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Waste Management in Iron & Steel Management

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                          Foreword
                    Steel Sector has been facing a lot of Challenges. Indian Institute of
                    Plant Engineers (IIPE) has been instrumental in creating platform for
                    the professionals The Indian in various industries and also for cross
                    industry exchange of views that have been instrumental in Plant
                    Productivity.

                    A seminar in Nov 2005 on “Approaches to Zero Break Down
                    Maintenance at Steel Plants” attended by over 150 delegates gave
                    an overwhelming response and the recommendations of the seminar
have become Industry guidelines. This seminar was not possible without the support of
SAIL, Bhilai Steel Plant.

A seminar titled “War on Waste”, inaugurated by Dr V Krishnamurthy, was organized in
Sept 2006, which covered Waste Management in various sectors. During the valedictory
function, chaired by the then Min. of State for Steel, it was recommended that the Industry
specific Waste Management should be organized at Plant locations. This seminar in Iron
& Steel Sector is the first in the chain of such Seminars to be organized eventually in
all industrial sectors including Oil & Gas, Fertilizers, Power (thermal, nuclear, hydro
etc) Mining, Textiles, Chemicals etc.

With the active support of SAIL (RSP), the present Seminar being organized at Rourkela,
will have Technical papers form all over the world including those from developed
and developing nations. The overwhelming response from Steel Entrepreneurs,
throughout the world, has already been demonstrated with participation of
delegates from USA, China, Nepal, Pakistan etc.

I am personally grateful to the Management of SAIL in general and the Managing
Director, RSP in particular for their wholehearted support.




J.S. Saluja
National Vice President, IIPE
& Chairman IIPE (Delhi)
                          Editorial
                   World Competitive standards, Rising input costs, Scarcity of raw
                   materials, Wastes generated like in other Sectors, have compelled
                   Mining, Iron & Steel Manufacturing Companies, to have a re-look
                   into their respective operations for all inclusive development and
                   sustainability in the operations. The Iron & Steel Industry is undergoing
                   a phase of uncertainty, volatility and speculation. Waste Management
                   in the Mining, Iron & Steel Industry has gained importance in view of
                   these dimensions.

The rapid advancement in technology, has made it possible to realize the task of Waste
Reduction, recycling in the Iron & Steel Industry on a sustainable basis.

This jointly organized by Steel Authority of India (SAIL) & Indian Institution of Plant
Engineers (IIPE) seminar, has been planned to share the experience, propagate and
recommend Waste Management potential of Raw Materials, socio economic and political
factors, which may have direct and indirect impact on the growth dreams of the Industry
among other relevant issues of strategic importance. The strategy of Wastes generated at
the Womb –the mine to the Tomb - the Salable Product is to be conceptualized in total.

The papers presented are a product of extensive and in depth analysis with incredible
amount of time spent by various writers.

An attempt has been made to highlight some of proven and established technologies,
systems, processes, and attitudes etc., which are essential for continuous world wide
efforts being made towards achieving Waste Management Practices available for further
improving the same. The contributions from experts and practicing professionals have
great potential for implementing these practices.




YP Chawla,
Program Director
National Jt .Secy. IIPE
   International Seminar “Waste Management in Iron & Steel Industry,
                         9-10 May, 2008, Rourkela
                                       Program

  Registration of Delegates - 9th May 2008 Friday 0800-1000 Hrs

      International Seminar “Waste Management in Iron & Steel Industry,
                                       9-10 May, 2008, Rourkela

                     Inaugural Session        9th May 2008 Friday



10.00-10.15           Welcome address               J S Saluja
10.15-10.30           About the Seminar             NP Singh ED Works RSP
10.30-10.45           Key Note Address              BN Singh MD RSP
10.45-11.00           Inauguration                  SK Roongta – Chairman, SAIL
11.00-11.10           Vote of Thanks                SS Mohanti- ED (MM) , RSP

              International Seminar “Waste Management in Iron & Steel Industry,
                                  9-10 May, 2008, Rourkela

                     Panelists for Panel Discussions: 10th May 2008
BN Singh – MD RSP- Head of Panel
Ms. Rita Singh – MD Mesco
R P Singh- Ex MD Bhilai Steel Plant , CEO JIndal Steels
PR Tripathi – Ex CMD NMDC,
Om Narayan – Sr.Vice President Tata Steels
PC Aggarwal Chairman / Hira Singh – MD      Ashok Steels , Nepal
SK Jain –      ED (O), SAIL
Ashok Kumar – ED (W), B S P
Dr. Xia Sheng- Director Engg. Bao Steel, China
Oommen, Dilip- CEO / A K Das – GM , Essar Steel
JS Saluja – National Vice President, & Chairman, IIPE, Delhi.

                     Valedictory Function 10th May 2008 Saturday 1620 -1655 Hrs
            16.20-16.30       Welcome         Balbir Singh ED P&A , RSP
            16.30-16.40         Summing up         NP Singh , ED Opns. RSP RSP
              16.40-16.50       Journey Forward    J S Saluja National Vice Pres. IIPE
              16.50-16.55       Vote of Thanks     YP Chawla National Jt. Secy
                                                   IIPE & Program Convener
Program of International Seminar on Waste Management in Iron & Steel Industry
08.00   10.00 Registration Registration of Delegates and Paper
                            Presenters
10.00   11.10 Inaugural     Please See Inaugural Program Details
               Session

11.10     11.25 Tea


11.25     12.45 Session 1      Present Practices:An Overview * Please see Paper Details.


12.45     13.30 Lunch

13.30     15.30 Session 2           Wastes in Iron & Steel Industry * Please see Paper Details.


15.30     15.50 Tea


15.50     18.00 Session 2      Wastes in Iron & Steel Industry * Please see Paper Details.
                Contd

                Cultural Program & Fellowship Dinner


Day 2 10th May 2008 Saturday


0900      10.30 Session 3      Solutions to Wastes in Iron & Steel Industry * Please see
                               Paper Details.

10.30     11.00 Session 4                   Business Opportunities in Waste Reuse in Iron &
                                            Steel Industry * Please see Paper Details .

11.00     11.20 Tea


11.20     13.00 Session 5

                               Success Stories
13.00     14.00 Lunch

14.00     16.00 Panel
                Discussions    Please see the List of Panelists
16.00     16.20 Tea

16.20     16.55 Valedictory
                               Please see Valedictory Program details
 Technical       Paper                             Topic                                       Author
  Session
                   1.0    Base Paper                                                 YP Chawla
Present Practices – An Overview
                   1.1    An Overview on Waste management In Steel industry          V K Dhawan
                   1.2    Zero Waste Journey at ESSAR Steel                          Dr. A.K Das. T Bhaskar
 Session-1
                   1.3    Need for Indian Iron & Steel Industry                      R.K.Agrawal A.Sengupta
                   1.4     The Waste Management and Integrated Utilization           Ming Kang, Bin Liu
Wastes in Mining , Iron & Steel Industry
                   2.1     Use of Sub-Grade Ore- A case study                        N.K. Mayson, A. Mukerji
                   2.2    Benefaction of Low Grade Iron Ore Fines                    S Madhavan, Saroj Jain
                   2.3    Waste management efforts in Iron Making zone (BF)          Sajeev Varghese
                   2.4    Solid Waste Management in Coke ovens                       S Roy Choudhury
                   2.5    Effective Biological Treatment of Coke Oven Byproduct      Dr. B N Das,
                          Plant’s Effluent For Removal of Ammonia, Cyanide &         B Vaidyanathan,
                          Phenol                                                     K K Manjhi, Dr. S P Kalia,
 Session-2         2.6    Waste Utilization & Minimization- BF                       DD Patra,
                                                                                     DM Srivastava,
                                                                                     S.Ranade.
                   2.7    Recycle Management of Waste Refractory                     S.K.Bandopadhyay,
                                                                                     P.K.Ray Choudhury,
                                                                                     D.Ghosh, S.K.Vadher,
                                                                                     S.Chandrasekaran
                   2.8    Management of Solid and Liquid Wastes at Coke Oven         K.K.Sanyal
                          and By Product Plant
                   2.9    Challenges and solutions for upgrading indian iron ores    Satyabrata Mishra
                          to optimize mining and steel production



Solutions to Wastes in Mining, Iron & Steel Industry)
                                                                                     R.P. Singh
                  3.1     BF Slag and SMS Slag utilisation
                                                                                     R.G. Segaran
                                                                                     S.Nanda,
                          Management of Splinters in SMS
                  3.2                                                                D. Mohapatra,
                                                                                     Md. Islamuddin ,

Session-3                 Effective Solid Waste Management in                        Dr. B N Das,
                  3.3
                          Iron & Steel industry                                      V V R Murty

                          Recycling of Wastes from Iron Steel Industries for Safer   B. Sankar R.K.Dutta
                  3.4
                          Environment & better productivity                          P.K.Pani
                                                                                     Navin Kumar
                  3.5     Waste Lubricating Oil Management
                                                                                     VK Srivastava, AK Oli
Business Opportunities in Waste Reuse in Iron & Steel Industry
                  4.1     EAF Dust Recycling Through Vitrification                   John H. Buddemeyer

                  4.2     Recovery and use of steel mill In-Plant Wastes             TC Inc.
Session-4
                          Use of Plastic Waste in Iron and steel Industries – An     R.B. Gupta,
                  4.3
                          Approach for Energy Reduction                              G.C Pattnaik
                                 INDIAN INSTITUTION OF PLANT ENGINEERS
                                               Office Bearers (2007-2008) - National

Sl.   Position           Name &                           Address                     Phone (O)         Fax           Phone (R)
                      Designation
        IIPE        Lt. Gen. SS Apte       E-506, Soma Vihar Appts,                  9810310233     011-26854525    011-26105997
1      Patron         PVSM (Retd)          RK Puram New Delhi- 110 022                                              011-26168627
                      Past NP, IIPE
         IIPE      Shri CK Varughese       E-218, Mayur Vihar,                       9868553045                     011-22779856
2
       Patron         Past NP, IIPE        Ph-IInd, New Delhi-91
        IIPE-        Shri NP Gupta         President Desein Indure Group, Greater    011-29211185
3
       Patron                              Kailash II, New Delhi 110048              011-29219566
      President     Shri Rakesh Nath       CEA, Sewa Bhawan, RK Puram, ND i          011-26102583                   011-22150630
4
                        Chairman
       National      Shri J S Saluja       Director ,Essar Group                     0120-6626666   0120-6626690    011-26942660
5
      Vice Pres.     Director Project      A-5, Sector-3, Noida-201 301               9811101181
       National      Shri YP Chawla        Zoom Developers (P) Ltd                   011-46591105   011-46591100    011-25262517
6      Jt. Secy            CEO             A-9 A , Ground Floor,                                                    011-25279434
                            .              Green Park, Aurobindo Marg , ND 16

                                                         Office Bearers - Delhi
Sl.   Position           Name &                           Address                     Phone (O)         Fax           Phone (R)
                       Designation
      Chairman     Shri J S Saluja         Director Essar Group                      0120-6626666   0120-6626690    011-26942660
1
                   Director Projects       A-5, Sector-3, Noida-201 301               9811101181
      Secretary    Shri YP Chawla          Zoom Developers (P) Ltd                  011-46591105    011-46591100    011-25262517
2                  CEO                     A-9 A , Ground Floor, Green Park,                                        011-25279434
                   .                       Aurobindo Marg , New Delhi-110016
      Secretary    Shri Satish Bahadur     Business Combine,                         9811916962                     011-23710822
3
        (Fin)                              13 Babar Road, New Delhi- 110 001                                          23319962
      Manager      Shri A Bhatnagar        IIPE, 664 Kamaljit Sandhu Block, Asian    011-26493252   011-26493974    011-22629546
4
                                           Games Village N D- 110 049                 9811319198

                     Steering Committee – Intl’ Seminar on Waste Management in Iron & Steel Industry
Sl.   Position           Name &                           Address                     Phone (O)         Fax           Phone (R)
                       Designation
      Chairman     Shri NP Singh., ED      Rourkela Steel Plant , Rourkela –         0661-2510641
1
                   (Works),                Orissa 769011
        Vice       Shri SS Mohanti,                          -do-
2
      Chairman     ED - MM
      Incharge     Shri RK Mathur,         HRD, address as above
3
      Co-ordn.     Sr DGM
      Resource     Shri S Ranadey ,        Iron Dept, address as above                 2523241                         2642111
4
       Person      GM ,
      Chairman     Shri J S Saluja         Director Projects ,Essar Group            0120-6626666   0120-6626690    011-26942660
5
                   Director                A-5, Sector-3, Noida-201 301               9811101181
      Progm.       Shri Y P Chawla,        Zoom Developers (P) Ltd                  011-46591105    011-46591100    011-25262517
6     Director     CEO                     A-9 A , Ground Floor, Green Park,                                        011-25279434
                                           Aurobindo Marg , New Delhi-110016

                   Coordinating Committee – Intl’ Seminar on Waste Management in Iron & Steel Industry
Sl.    Position     Name & Designation                     Address                     Phone (O)        Fax           Phone (R)
       Chairman     Balbir Singh ED P&A       Rourkela Steel Plant , Rourkela –      0661-2611140
 1
                                              Orissa 769011
       Incharge     Shri JC Mohapatra,                                               0661-250050                       2646306
 2
        Co ordn     COC,                                     --Do--                  94370-85885
 3      Member      Shri GN Mathur                          Ex. CBIP                                                011-25079178
                    Shri P. Bansal, SAIL                     --Do--
 4       --Do--
                    HQ
                    Shri Mahesh                          Rep RSP Delhi              22531226,                      98685 14255
 5       --Do--
                    Takhtani,                                                       2240 3564
       In charge    Shri Narayan Pati –       0661-2510920                          094370 47402    0661-2642
 6    Reception     DGM – COP                                                                       402
      Committee
       In Charge    Shri BB Mishra            0661 2511288                          094379 63741
 7      Seminar
      Task Force
 8       --Do--     Shri A M Pujari           0661 2510395                          094379 63732
                    Shri Satish Bahadur,         President, Business Combine          9811916962                    011-23710822
 9       --Do--                                                                                                       23319962
                    Shri P Varshney,            Power Trading Corp., New Delhi       98101 53223
10       --Do--
                    Vice President,
                    Technical Committee – Intl’ Seminar on Waste Management in Iron & Steel Industry
Sl.     Position    Name & Designation                   Address                     Phone (O)          Fax           Phone (R)
        Chairman    Shri SK Jain – ED      SAIL HQ Ispat Bhavan Lodi Rd.              2222388                          2241777
    1
                    (Opns)                 New Delhi 110 003                          2221023                          2242339
    2    Member     Shri GS Bhatia,        Rourkela Steel Plant
    3     --Do--    Shri MR Diwakar, GM    Rourkela Steel Plant
    4     --Do--    Shri D Pal GM ,                Rourkela Steel Plant               2510359                         2646326
          --Do--    Shri Mohan Hirani,       D-II /2449, Vasant Kunj, ND-70                                         011-26138209
    5
                    Ex-GM, NTPC
          --Do--    Shri SK Jain, Vice     Essar Group
    6
                    President,                A-5, Sector-3, Noida-201 301
          --Do--    Shri L N Sharma,       GM In charge SAIL Burnpur
    7
                    SAIL

                                                         AMMP-Division
Sl.     Position    Name & Designation                   Address                      Phone (O)          Fax          Phone (R)
        Chairman    Maj Gen S K Sharma      ADG, EME (ESM) AHQ, New Delhi           011-23011423    011-23018608    011-25691904
    1
                           ADG             R-256, D.S., Arjun Vihar, Delhi Cantt.    9350040427
           V.        Shri Mohan Hirani        D-II/2449, Vasant Kunj, ND-70                                         011-26138209
    2
        Chairman
        Secretary     Brig Kuljeet Singh       DDG EME (ESM) , AHQ, ND              011-23019478    011-23018461    011-24677784
    3


                                                  Advisory Board Members
Sl.      Position   Name & Designation                   Address                     Phone (O)          Fax           Phone (R)
         Member      Shri Rakesh Mehta                Chief Secy Delhi
    1
         A. Board
          --Do--      Shri Rakesh Nath              CEA Sewa Bhawan,                011-26102583    011-26109212    011-22150630
    2
                           Chairman                RK Puram, New Delhi
           --Do--        Dr PS Rana                                                  9810131406                     011-26493129
    3
                      Ex-CMD, HUDCO
    4      --Do--       Shri Y. Prasad          Cmn. Utrakhand Jal Vidyut
           --Do--     Shri Chandan Roy          NTPC Ltd SCOPE Complex              011-24360232    011-24363478    011-24692543
    5
                        Director (Oprn)          Core V Lodi Road ND-3
           --Do--       Shri U C Misra                CMD, BBMB                                                     0124-4043679
    6
                        Director (Pers)
           --Do--      Shri K K Khanna       SAIL , Ispat Bhawan, Lodhi Road,       011-24367105    011-24367250   011-26492434
    7
                        Director (Tech)              New Delhi 110 003
           --Do--     Shri S K Roongta       SAIL , Ispat Bhawan, Lodhi Road,       011-24368094    011-24367015   011-26493004
    8
                       Chairman, SAIL                New Delhi 110 003
           --Do--     Shri PC Aggarwal        Ashok Steel Inds. Ltd Bhagmati        9771-243148       009-771-
                           Chairman         Chambers Milan Marg. Kathmandu          9771-242395        4226477
    9
                                                          PO-121112,                                     009-
                                                           KA-2-2/18                                 7753520155
           --Do--      Shri V S Verma           Sewa Bhawan RK Puram,               011-26102583    011-26197267    011-26492024
 10
                           Member                Sec-I, New Delhi-110 066
           --Do--     Shri K Ravi Kumar       BHEL , Siri Fort, Asian Games         011-26001001    011-26492043    011-26493933
 11
                             CMD                     Village, ND-110049
           --Do--       Shri J Mehra         Essar Group A-5 Sector 3, Noida        0120-6626602    0120-6626690
 12
                           Director
           --Do--      Brig AK Adlakha      AIREA ,81/2, Adchini, Sri Aurobindo     011- 51071555   011-51070555    0120-2430769
 13                   Executive Director           Marg, ND – 110017.                 51072555
                                                                                     9810039364
           --Do--       Shri NP Gupta         Desein Indure Group , Greater         011-29211185    011-29219566
 14
                          President           Kailash-II, New Delhi-110 048          9810096139
 15        --Do--       Ms Rita Singh                  MD , Mesco
           --Do--       Dr A K Lomas          Mineral Exploration Corpn Ltd.,       0712 2510289                    0120-4260204
 16
                             CMD                          Nagpur                                                    0712-2510338

                                                         Vice Chairman
Sl.     Position    Name & Designation      Address                                 Phone (O)       Fax            Phone (R)
1       --Do--      Shri RC Gupta           Desein Indure Group Greater             011-29223761    011-29218393   011-26132279
                    Vice President          Kailash-II, New Delhi- 110 048          9810019907                     011-26132193
2       --Do--      Shri HL Tayal           PGCIL, Corporate Centre                 0124-2571957    0124-2571956   011-26894118
                                             th
                    Exe. Director           7 Floor, Plot No-02 Sec.29              9811612124
                                            Gurgaon- 001
4       --Do--      Shri V K Dhawan         SAIL, Ispat Bhawan, Lodi Road,          011-24366740    011-24366470   0120-2771278
                    ED (Operations)         New Delhi
                                                    nd
5       --Do--      Srhi P Varshney         PTC, 2 Floor, NBBC Tower 15             011-51659132    011-51659145   011-26277936
                    Vice President          Bhikaji CamaPlace ND 66                 98101053223
6       --Do--      Shri Digvijai Nath      Office of ED Subanisiri Basin        03788-225832                  0129-2428574
                    ED                      Projects NHPC Ltd, Ziro, Arunachal   09436068834
                                            Pradesh-791 120
7       --Do--      Dr GS Yadava            IIT Hauz Khas                        011-26591272                  011-26591615
                                            New Delhi & Chmn. Institution of     9891334151                    26856058
                                            Engineers Delhi                                                    26861834

                                    Standing Committee-Industrial Sector’s Conveners
S.       Category    Name & Designation                  Address                   Phone (O)        Fax           Phone (R)
No
 1      Convener         Dr. KK Govil              132 Vasant Enclave             9811165557                    011-26147514
         Power          Ex- Dir (P), PFC           New Delhi- 110 057
          Sctr.
    2   Convener     Shri G Ojha Director    SAIL, Ispat Bhawan, Lodi Road,      011-24367259   011-24367250    011-264925174
          Steel                                        ND-110003
         Sectr.

                                                   Executive Committee
S.       Category    Name & Designation                  Address                   Phone (O)        Fax           Phone (R)
No
 1       Member       Col Mahesh Mathur                    AHQ                    9810843739                    011-25089974
 2        --Do--        Shri YK Mattoo        Simon India Ltd., Devika Tower,     9810492884                    011-26843281
                          Sr Adviser               Nehru Place, ND-19
3         --Do--       Shri Ashish Jain          ONGC Limited New Delhi          011224064651                   0135-2720278
                            Dy. S.E.
4         --Do--         Shri SK Kaila           Kaila Technical Services                       011-27941082    011-27941082
                          Consultant           24/C-9, Sec-8, Rohini , ND 85
6         --Do--        Shri SK Goyal               National Fertilizer,
                        Dy. GM (Mech)                    Panipat
7         --Do--       Shri L N Sharma                    SAIL,
                         GM Incharge
8         --Do--       Shri A B Agrawal        NHPC Ltd.,Salal Hydroelectric     01991-255433                   011-22624985
                       General Manager       Project PO Jyotipuram, Vai Reasi,
                                                    Dist Udampur J&KK
9         --Do--        Shri AG Ansari             NHPC Limited Sector-33        0129-2258834   0129-2272806     9810546695
                        Chief Engineer               Faridabad-121 003
10        --Do--       Shri S Majumdar            PGCIL, Corporate Centre        0124-2571955   0124-2571956    011-26890926
                                                 th
                       Executive Director      7 Floor, Plot No-02, Sec.29,
                             (DMS)                   Gurgaon-122 001
11        --Do--          Shri LC Jain         M/s Flowmore Pvt Ltd A-292,       011-30623740       011-        011-26511605
                       Vice President (P)      Mahipalpur Extension, N.H.-8        9313980341    26783278,
                                                      New Delhi - 110037                         26781483
International Seminar on Waste Management in
             Iron & Steel Industry
                           Jointly organized by:

                                            INDIAN INSTITUTION OF PLANT
                                            ENGINEERS
                              Co Sponsored by :
                   BeeKay Engineering Corporation
                         www.beekaycorp.com




                            Knowledge Partners:




                                                     SailCon
                                                     Rourkela
                                                     Bokaro
                                                     Bhilai

                                            Pacific Sterling Inc. USA




  A Premier Project Development Company
Base Paper                                                                         [1.0 / 1 ]


             Base Paper: YP Chawla CEO Zoom Developers P Ltd.
                                  National Jt .Secretary IIPE
                     Iron Pillar Erected by King Ashoka before Christ

     This paper is intended to give some inputs and data that has been collected for
reference by our Paper presenters , delegates to work out the Strategies intended to be
developed in this seminar and come up with recommendations that will make this
Industry self sustained to the extent possible targeting Zero Waste. The reports and
data referred in this paper might have gone changes at the time of Seminar. These
have been updated at the time of Compilation and are intended for giving direction to
the process of interaction and to be referred as base paper during the Seminar.
      The Steel Industry is presently vibrant due to demand as well as volatile due to
high cost of inputs. The World Steel industry has entered a new phase. Finished steel
consumption in the five years since the start of the millennium has increased by 233
million tonnes - an average annual rate of around 6 percent. This compares with a 1.2
percent average yearly rise in the previous three decades to 2000.
     Large Steel inventory building has occurred around the world. The talk of
shortages of raw materials has possibly prompted buyers to carry higher stock levels
than previously considered necessary. Fluctuating interest rates at moderately low level
the world over (barring India) have made inventory building exercise less painful than in
the past.
      On the other end, Chinese government is deliberating on avoiding overheating of
Chinese economy by attempting to reduce growth in key industrial sectors, including
steel.
      Overall, the World has not seen so much demand in last 20 years as it is now. The
global steel demand is seeing the rise on the back of accelerated infrastructure activity
in China, CIS and India, housing boom in USA, and white goods resurgence in Europe.
During the recent recessionary phase, the industry has consolidated in terms of
ownership as well as mothballing of inefficient capacities. And the Steel prices continue
firming up.
     The Demand of Steel in India, China and other Asian countries is led by emphatic
investment activities in infrastructure. While, the reconstruction work in Iraq is expected
to fuel further demand for steel over the next few years. China is consuming steel like
never before for its infrastructure with investments such as Three Gorges project on
Yangtze as well as part of its build up to the Beijing Olympics in 2008 and the Shanghai
Expo in 2010.
Base Paper                                                                       [1.0 / 2 ]


    In Europe, there is demand from housing and white goods industry which is on
buoyancy, according to industry estimates.
     The global metals and mining industry grew by 17.5% in 2007 to reach a value of
US$1,457.4 billion. In 2011, the global metals and mining industry is forecast to have a
value of $1,600 billion, an increase of about 12% since 2007.
     The demand supply gap is expected to increase driving the steel prices
northwards, even as the global steel industry is not prepared for this demand onslaught.
Approx. 90 percent of global steel demand growth over the next two years will take
place in the emerging or developing nations of the world.
     Steel is an input for Global Industry. Steel Sales account for 67 % of the global
industry’s value.
      The challenges that the Industry faces today are the requirement of a sustainable
development by meeting the needs of our present generation without compromising the
ability of future generations to meet their own needs. The Industry is required to
understand the importance of a sustainable approach to the operations of any company
across the entire value chain, from the extraction of raw materials from the Mine through
to the manufacture of finished steel products and the distribution to our customers.
(Womb to Tomb Approach)
     Steel is an integral part of our developing world, both now and into the
                    future. As one of the most common materials we come in contact
                    with everyday, it is difficult to imagine a world without steel. The
                    reason for this is steel’s strength, versatility and ability to be
                    recycled. Steel can be used many times over with re-processing
                    techniques maintaining properties and qualities, something that
                    makes it unique from other materials.
Base Paper                                                                         [1.0 / 3 ]


     The Challenge of the high energy Cost (Iron and Steel sector is the largest
energy consuming sector in the world, devouring 15% of world industrial energy)
coupled with a pressure on the Carbon emissions and, the employing Competitive
Specific Energy consumption pattern is the challenge to the Technology Providers.
       The benchmarking of Energy Consumption is another challenge by India being a
net importer of Crude Oil. In India, average specific energy consumption in steel making
is in the range of 6.2 –8.2 GCal/TCS (vis-à-vis international value –4-4.5 GCal/TCS)



                                                    Similarly      benchmarking        Co2
                                               emissions, the average CO2emission is
                                               in the range of 2.2 –3.2 T/TCS in
                                               India(vis-à-vis international value of 1.5 –
                                               1.7    T/TCS)          CO2emissions       in
                                               steelmaking stem from the intense
                                               consumption of fossil fuels –for thermal
                                               energy,      coke      making,      process
                                               requirement and electrical energy mainly
                                               is another task to be considered.


                                                     Carbon dioxide emissions from steel
                                               production, which range between 5 and
                                               15% of total country emissions in key
                                               developing countries will continue to
                                               grow as these countries develop to cater
                                               to global steel demand


                                                   Reducing energy intensity is
therefore not only beneficial in saving scarce resources but also in reducing carbon
emissions and thus mitigating global climate change.
      With increasing energy prices, diminishing reserves of conventional forms of
energy, and increasing GHG emissions, it is a need of the hour for the iron and steel
industries of the developing world to a take sustainability approach for utilization of the
limited fossil fuel reserves of the earth.
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                                                                         GHG emission
                                                                  reduction in iron and
                                                                  steel manufacturing
                                                                  facilities can be done
                                                                  through        different
                                                                  routes               like
                                                                  replacement              /
                                                                  switching of CO2
                                                                  intensive fuel (e.g. oil
                                                                  to gas, coal to gas),
                                                                  energy efficiency in
                                                                  the            process
technology, waste processing, waste heat recovery projects including power generation,
energy savings by elimination of reheating processes. Such technological initiatives for
curbing GHG emissions, requires substantial capital investment, because of which
India, with its mixed bag of plant and machinery (power + industrial) in terms of old,
outdated industrial and power generation equipment coexisting with the latest, most
modern machinery, is widely seen as a key CER supplier under CDM
     Some steel companies in India have initiated ‘Climate Change initiatives’ towards
improving its energy performance through fuel substitutes, modernization, recovery &
reuse of by-product energy. In integrated steelmaking, a major source of energy and
CO2 emissions is from the manufacturing of coke consumed in the blast furnaces. With
continuous inflation in global steel demand and supply, there will be a necessity for
increasing amount of coke production
     In this Context the Waste Management in Iron & Steel Industry becomes important
, covering the complete cycle of Process from Mining Ore to Saleable Product has been
planned to debated on transiting the process from ‘end - of - Pipe approach’ to
Reduction, Recycle & Reuse i.e. Cleaner Production leading ultimately to Zero
Emissions’ in continuing with Zero Philosophy .
    Zero Defect – (Total Quality Management) ; Zero Inventory- (Just in Time
Production)
     Zero Emission – (Total Productivity): Reengineering of the Manufacturing
Processes for fully Utilize the resources within Industry for higher Revenues and Jobs.
Zero Emissions extend as under :
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    End-of Pipe           Cleaner Production                   Zero Emissions
     approach          (Reduce, Recycle, Reuse)
                                                                (Total Productivity)
                                                     Adding New Industry in Up Stream,
          Minimizing effects on Down Stream
                                                     Utilizing Wastes in existing Industry
                   Minimize Waste                                  Value Addition
                   Cost Reduction                                Revenue Increase
 Continuing with                                     Developing Industry Cluster for using
 Existing             Modifying the Existing Unit Waste as Input to next Industry
 Production           Process
 Process
 Measures at the
 Outlet    of   the        Input- Output Analysis             Output- Input Connection
 process.
 Water,     Energy, Waste Minimization through
 Wastes               Production             Process Integrated Approach- Holistic Approach
                      Modification
    Industry is
     presently
                       Transit Stage to next stage                 Ultimate Goal
  focused on the
       above
     Wastes Recycling will lead to Minimization of exploitation of Natural Resources
      The factors that require Measurement of the industries’ sustainability are to:
       Develop indices of benchmark
       Develop “successful” standards and labeling programs
       To learn “best-of-kind” operation
       To build a kind of “Energy Code”
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        To facilitate technology deployment by gathering information on “State-of-the-
Art” technologies
     The Technology of Manufacture is required to be examined for better productivity.

                              o 40 per cent of the world’s steel production takes
                                  place through the EAF route, which manufactures
                                  steel from scrap metal.
                              o Steel recycling is common practice and scrap steel
                                  has become a valuable commodity because there
     is a technology that can accept it. Engineers and Scientists to take on exciting
     route to develop technologies and processes to be able to take into account all
     Waste Materials. The possibilities are endless!
   o Enhancing existing processes to be able to use all kinds of Waste resources to
     make the Sustainable Materials Processing, including recycling of waste in
     steelmaking, lowering of energy and emissions in processing, iron and
     Steelmaking technologies.

    While debating various issues, the Industry Recent High Lights on the
Resource Position may also be examined:
   o India's iron ore resources can increase significantly as per ICRIER
   o Iron Ore reserves can increase significantly from the current estimated level by
     increasing investment & exploratory efforts.
   o Concerns over reserves in view of the proposed capacity additions need to be
     dispelled, as significant share of steel gets recycled and efforts will made through
     improvement in technologies and waste recycling , demand for iron ore is to be
     attempted to be stable.


      The studies have indicated that in the current scenario, export restrictions will
make it difficult to take care of excess fines. Restrictions on trade in iron ore will also
restrict the economies of scale to Indian mining Companies and they may remain
inefficient in global comparison forever. Such restrictions could also lead to closure of
some of the mines, leading to loss of direct and indirect jobs.
     India's iron ore production in 2006-07 was around 181 million tonne, which was in
excess of the consumption level. India exported about 93 million tonne during that fiscal,
which is expected to come down to about 88 million tonne in the current fiscal. Nearly
80% of exported ores are fines, because those are not adequately used in India. India's
competitiveness in the Chinese market has already started falling, the study points out.
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World Scenario on Steel

  Sl          Country           2007         Share each          Sl            Country           2007      Share each
         Total                  15.3
  1      Japan                  3.364         22.00%             22    Chile                     0.034       0.20%
  2      Brazil                 2.418         15.80%             23    Saudi Arabia              0.027
  3      US                     1.551         10.10%             24    Sweden                    0.022
  4      Belgium                1.539         10.10%             25    Tanzania                  0.022
  5      India                  0.977          6.40%             26    Argentina                 0.021       0.10%
  6      Pakistan               0.687          4.50%             27    Indonesia                 0.016
  7      Turkey                 0.64           4.20%             28    Malaysia                  0.015
  8      Holland                0.509          3.30%             29    Philippines               0.008
  9      UK                     0.481          3.10%             30    North Korea               0.008
  10     France                 0.451          3.00%             31    Norway                    0.007
  11     Taiwan                 0.384                            32    UAE                       0.006
  12     South Africa           0.382          2.50%             33    Egypt                     0.006
  13     South Korea            0.382                            34    Morocco                   0.006
  14     Iran                   0.376                            35    Russia                    0.005
                                                                                                             0.00%
  15     Kazakhstan             0.27           1.80%             36    Mexico                    0.004
  16     Italy                  0.213          1.40%             37    Bengal                    0.003
  17     Canada                 0.169          1.10%             38    Burma                     0.002
  18     Germany                0.096          0.60%             39    Algeria                   0.002
  19     Viet Nam               0.082          0.50%             40    Hong Kong                 0.001
  20     Australia              0.073                            41    Sri Lanka                 0.001
  21     Thailand               0.038          0.20%             42    Mozambique                0.001

            SUMMARY OF APPARENT CONSUMPTION (Million Tonnes) OF FINISHED STEEL 1998 to 2008
Region                  1999        2000        2001      2002        2003       2004    2005      2006     2007         2008
European Union          152.9      160.0        156.5     156.7       154.4      162.1   164.1     167.0   167.3        166.5
European Union          128.6      132.6        129.5     127.4       137.4      144.1   145.4     146.9   146.9        146.2
Other Europe            18.2        22.1        20.6      20.7        24.1       26.0    27.0       28.0    29.7         30.5
Former USSR             31.0        38.8        41.2      38.3        43.4       47.0    50.0       52.0    53.5         55.0
NAFTA                   142.4      149.2        132.1     135.1       132.9      152.5   153.5     157.5   157.5        155.5
S America               24.8        28.1        28.4      27.4        28.1       31.5    32.5       34.5    35.5         36.5
Africa                  15.4        15.0        16.3      17.4        17.1       17.5    18.0       18.5    19.0         19.0
Middle East             16.6        18.4        19.1      20.9        21.6       23.5    25.0       26.5    27.5         28.5
PR China                122.6      124.6        153.4     185.6       230.8      257.4   291.4     302.0   310.0        322.0
Japan                   68.9        76.1        73.2      71.7        73.8       75.5    76.5       76.8    77.0         76.8
Other Asia              109.0      119.5        118.9     129.5       133.3      141.0   143.5     145.7   147.0        149.2
Oceania                  6.7           6.4       6.3       7.1         7.5        7.5     8.0       8.0      8.5          8.5
WORLD TOTAL             708.5      758.2        766.0     810.4       867.0      941.5   989.5    1016.5   1032.5       1048.0
 Region             1999       2000       2001      2002     2003                2004    2005      2006     2007         2008
Totals may not be arithmetically correct because of rounding
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                                                                          Ref : MPES UK
Governmental Interventions on Iron & Steel:
      China began to levy a 5% export duty on coke in November 2006. It raised the tax
rate to 15% on June 1st 2007. As the world's largest coke producer and exporter, the
country has a say in pricing for coke on international markets. Foreign buyers chose to
bear price rises based on the 15% export duty.
       India : Govt. of India in order to cool down the surge in steel prices in India by
improving availability is planning to duty cuts on raw and finished material and the
inflation and with a view to controlling prices exports would be disincentivised with levy
of export duty. Imposition of export tax , Reduction of custom duty on Iron & Steel
,Abolishing Countervailing duty on re bar imports etc.

Prospects for International Steel Industry
     Present status of the International Steel industry Steel is primarily a raw material
based industry as for the production of one tonne of steel, an integrated plant consumes
4 tonnes of raw materials.
     India with its abundant availability of high grade Iron ore, the requisite technical
base and cheap skilled labour for the development of steel industry and to provide a
strong manufacturing base for the metallurgical industries.
      India presently accounts for less than 5% of the global output of Finished Steel and
1% of global trade. The per capita consumption of 27 kg. is also well below even the
Asian average of 128 kg. China on the other hand shall consume 280 million tonnes of
Steel, including 30 million tonnes through imports against the total consumption of 30
million tonnes by India.
    Chinese Steel and metallurgical industries have provided a major thrust to the
economic development, GDP growth and generation of massive employment
opportunities.
     In India , Non-integrated or the secondary producers accounting for over 50%
output of the Finished Steel but without any captive mines have not gained much due to
the sharp rise in the prices of Melting scrap, Sponge Iron, Coke, Iron Ore and other
inputs.
      The growth has been mainly export based, boosted by the high global prices and
liberal export incentives.
      The current status of the Indian Steel industry amply reflects the vast potential for
the future growth of steel and allied industries through integrated planning to exploit the
potential and the Indian steel is indeed poised for a quantum jump in the next decade.
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      Structure of Indian Steel Industry Indian Steel Industry comprises of several
interdependent and interlinked segments for value addition, broadly classified as the
integrated or the majors producers and non-integrated or the Secondary Producers.
India has played a pioneering role in the recycling of scrap for the production of Steel
through EAF/Induction Furnaces and the rolling of both the Long and the Flat Products
in Mini/Midi Mills at highly competitive prices. The Secondary Sector accounted for over
50% of the total indigenous output of Finished Steel
     The Secondary Producers focus on the production of high grade steels and
specialty products to meet the specific requirements of the industry and the
development plans must include the strengthening of the Secondary sector along with
the major producers.
     Ample scope for the reduction of production costs by the Secondary Sector
through the technological up-gradation, particularly by the Electric Arc and the Induction
Furnace Producers, through the conversion of Electric Arc Furnaces to Twin shell
Furnaces.
      Technological developments in the past decade, the non integrated producers and
the integrated compact Mills have emerged as low cost producers of Finished steel due
to low capital investment and breakeven points intense customer orientation and
flexibility in altering the product wise.
     The Sponge Iron/Mini/Midi Rolling Mill route appears to be the appropriate for a
large country like India and the requisite support be provided to the Secondary
Producers on merits, for the modernization and expansion projects and these Mills
adopting Waste Recycling Techniques.
      Key role of the domestic market The expansion of the domestic market in a huge
country like India holds the key to the future growth of the steel industry and the basic
input like Steel should obviously be utilized for the industrial and the economic
development of the country. Besides, the export prices and markets are subject to wide
ranging fluctuations triggered by economic and political developments in different parts
of the world.

Targets of the Seminar
      The major responsibility for the implementation of the development plans and
strategies shall however rest on the industry through (i) Benchmarking with the leading
global steel producers in term of the production costs, quality and service, to meet the
global competition in the low tariff regime. (ii) Customer orientation and collaborative
research and development with the metallurgical industries, to develop cost effective
products for the domestic and export markets and to develop India as a low cost global
Base Paper                                                                         [1.0 / 10 ]


manufacturing base for the metallurgical products. (iii) Development of rural markets
and providing requisite infrastructure support for fabrication and after sale service in the
rural areas. (iv) Promote construction of steel intensive commercial buildings and
domestic housing in collaboration with Architects and town planners.

To Resolve
Protection of the Biosphere
     We will reduce and make continual progress toward eliminating the release of any
substance that may cause environmental damage to the air, water, or the earth or its
inhabitants. We will safeguard all habitats affected by our operations and will protect
open spaces and wilderness, while preserving biodiversity.
Sustainable Use of Natural Resources
     We will make sustainable use of renewable natural resources, such as water, soils
and forests. We will conserve non-renewable natural resources through efficient use
and careful planning.
Reduction and Disposal of Wastes
     We will reduce and where possible eliminate waste through source reduction and
recycling. All waste will be handled and disposed of through safe and responsible
methods.
Energy Conservation
     We will conserve energy and improve the energy efficiency of our internal
operations and of the goods and services we sell. We will make every effort to use
environmentally safe and sustainable energy sources.

Risk Reduction
       We will strive to minimize the environmental, health and safety risks to our
employees and the communities in which we operate through safe technologies,
facilities and operating procedures, and by being prepared for emergencies

                                            ****
Present Practices – An Overview                                                    [1.1 / 1 ]


     AN OVERVIEW ON WASTE MANAGEMENT IN STEEL INDUSTRY
                                  V.K. Dhawan ED (SAILCON)
                                  Steel Authority of India Limited
                                            New Delhi


1.   Waste Management: For Sustainable Development
     Development of an industry in the present age of ‘Sustainable Development’ is
synonymous with the concern for environment along with its social and economic goals.
Steel is the driving force of economic progress. The intrinsic ability of steel to be
completely recycled offers good prospects for ‘Sustainable Development’ of the steel
industry. The challenge for steel in the new millennium is no longer to prove its capacity
to create growth, but to show that it is a material with a future, resolutely adapted
through recycling /reuse of wastes to the integrated concept of ‘Sustainable
Development’. When the steel industry is to remain committed to ‘Sustainable
Development’, there is no option for the industry other than gainful utilisation of all the
wastes.
     One of the major concerns of world steel industry is the disposal of wastes
generated at various stages of processing. The global emphasis on stringent legislation
for environmental protection has changed the scenario of waste dumping into waste
management. Because of natural drive to be cost-effective, there is a growing trend of
adopting such waste management measures as would convert wastes into wealth,
thereby treating wastes as by-products. This has led to aiming at development of zero-
waste technologies. The technologies developed to economically convert wastes of
steel plants into wealth provide new business opportunities for prospective
entrepreneurs. Such technologies are divided in two categories, namely technologies
for gainful utilization of wastes in manufacture of conventional products and those for
gainful conversion of wastes into altogether new products.

2.   Waste Management
     Waste management is the collection, transport, processing, recycling or disposal of
waste materials, usually ones produced by human activity, in an effort to reduce their
effect on human health or local aesthetics or amenity. A subfocus in recent decades has
been to reduce waste materials' effect on the natural world and the environment and to
recover resources from them.
    Waste management can involve solid, liquid or gaseous substances with different
methods and fields of expertise for each.
Present Practices – An Overview                                                  [1.1 / 2 ]


     Waste management practices differ for developed and developing nations, for
urban and rural areas, and for residential, industrial, and commercial producers. Waste
management for non-hazardous residential and institutional waste in metropolitan areas
is usually the responsibility of local government authorities, while management for non-
hazardous commercial and industrial waste is usually the responsibility of the generator.

3.   The Waste Hierarchy
     The waste hierarchy refers to the "4 Rs" reduce, reuse and recycle, restore which
classify waste management strategies according to their desirability in terms of waste
minimization. The aim of the waste hierarchy is to extract the maximum practical
benefits from products and to generate the minimum amount of waste. The waste
hierarchy remains the cornerstone of most waste minimization strategies.




     In general by reducing or eliminating wastes an industry can:

     •     Solve the waste disposal problems created by land bans
     •     Reduce waste disposal costs
     •     Reduce costs for energy, water and raw materials
     •     Reduce operating costs
     •     Protect workers, the public and the environment
     •     Reduce risk of spills, accidents and emergencies
     •     Reduce vulnerability to lawsuits and improve its public image
     •     Generate income from wastes that can be sold.
Present Practices – An Overview                                                    [1.1 / 3 ]


3.1 Waste Minimization Techniques
      Waste minimization includes any source reduction and/or recycling activity
undertaken by a waste generator (i.e. any business that produces waste through their
operations). These activities result in a reduction of waste produced and/or a reduction
in the toxicity of the waste. Some examples of waste minimization techniques are listed
below.

3.2 Source Reduction Techniques
    •   Change the composition of the product to reduce the amount of waste
        resulting from the products use.
     •     Reduce or eliminate hazardous materials that enter the production process.
     •     Use technology (including measuring and cutting) to make changes to the
           production process; equipment, layout or piping; or operating conditions.
     •     Purchase what you need to avoid waste from unwanted materials.
     •     Good operating practices such as waste               minimization programs,
           management and personnel practices, loss             prevention, and waste
           segregation help to reduce waste at their source.

3.3 Recycling Techniques
    •   Return waste material to original process.
     •     Use the waste material as a raw material substitute for another process.
     •     Process waste material for resource recovery.
     •     Process waste material as a by-product.
     •     Investigate contractors to recycle waste material.

3.4 Waste Management In Steel Industry
     Metallurgical industry is both capital and energy intensive and its production
volumes are very high. Process chains within the industry are long. Many different
technologies are applied and the industry has a significant impact on the environment.
Steel industry is a mature industry with overcapacity as well as the strongly cyclic nature
is a problem. In the future, the competitiveness of the steel industry depends on
reducing the production time-to-market time, lowering the production costs, increasing
the performance of products and minimizing the environmental impacts. One of the
major concerns of world steel industry is the disposal of wastes generated at various
stages of processing. Because of natural drive to be cost-effective, there is a growing
trend of adopting such waste management measures as would convert wastes into
wealth, thereby treating wastes as by-products. This has led to aiming at development
of zero-waste technologies. The technologies developed to economically convert
Present Practices – An Overview                                                              [1.1 / 4 ]


wastes of steel plants into wealth provide new business opportunities for prospective
entrepreneurs.
       On an average about 400 Kg of solid by products is generated in the steel industry
per tonne of crude steel and the world steel industry in 2006 had produced about 1.239
billion tonne of crude steel, thereby generating huge wastes. Major share of this (70-
80%) consists of Blast Furnace Slag and Basic Oxygen Furnace Slag. These wastes
are an ecological hazard. The total steel production in India in 2006 was about 44
million tonne and the waste generated annually was around 14 million tonne with
associated ecological problems. There remain opportunities in utilization of the
generated wastes into commercial products. Technologies have been developed in
most of the developed nations of the world for utilization of the generated wastes. In
India though utilization of wastes has begun it is still quite some time before there is
total utilization.
      The objective of this paper is to bring out the scope of waste management in steel
plants through waste auditing, yield loss improvements and by implementing zero waste
programs in respective areas for waste minimization and match with the corresponding
figures in the developed world and again identify measures to minimise generation of
wastes, maximise utilisation of generated wastes and achieve ‘zero waste’ status.
      Integrated steel plants usually consist of Coke oven, blast furnace, sinter plant,
steel melting shop and rolling mills. In addition to the above the plants may have
auxiliary units like oxygen plant and power plant and Engineering shops for their own
uses. In India, Steel Plants are facing the challenge to make and process steel without
adversely impacting the environment, from complying with the requirements of the law
to adopting environmentally friendly, clean technologies. The Ministry of Steel has been
emphasizing on the importance of solid waste management. More than 30 per cent of
solid waste generated in the country’s steel industry is being economically used and it
needs to be further improved.
                     Solid waste arising from different major shops:
        Sl no   Major Shop        Major Solid Wastes
        1       Co & BPP          Coke & Coal Dust, Tar sludge, Sulphur Muck, Acid sludge,
                                  Refractory waste
        2       Sinter Plant      GCP, Sludge
        3       RMP               Lime fines, ESP dust
        4       BF                BF Slag Flue dust, BF GCP Sludge, Refractory wastes
        5       SMS               LD Slag, GCP sludge, Refractory wastes
        6       Rolling Mill      Mill Scale, Scrap, oil sludge
Present Practices – An Overview                                                        [1.1 / 5 ]


     Typically, in an integrated Steel Plant, to make one tonne of crude steel even with
good quality raw materials and efficient operation requires 5 tonne of air, 2.8 tonne of
raw materials and 2.5 tonne of water. These will produce in addition to one tonne of
crude steel, eight tonne of moist dust laden gases and 0.32 tonne to 0.5 tonne of solid
waste.
                   A Glance to typical Solid Waste utilization in a SAIL plant
                                                                                          ‘000T
                               2006-07                              2007-08
     Solid Waste                Actual                                Plan
                     Gen            % Utilization   Generation   Utilization     % Utilization
 BF Slag             1743           41              1890         984             52
 BF Flue Dust        62             100             55           55              100
 LD Slag             397            78              485          403             83
 Lime Fines          25             100             30           30              100
 Mill Scale          76             100             80           80              100
 Refractory          12             50              15           7.5             50
 Carbide             3.5            100             3.5          3.5             100
 Sludge

     Taking clue from the waste utilization being done as shown above a holistic view point on
waste management in iron & steel industry is being conveyed in this paper.

4.      Scope of Management of Steel Plant wastes involves
        •   Waste Audit-- Quantification, characterisation and management of all types
            of wastes in a steel plant, analysis of the wastes and characterisation of
            hazardous wastes,related Ecological problems
        •     Yield loss improvements--Reduce, Reuse, Recycle and Restore-      The
              Four R’s, Reduce, Reuse, Recycle and Restore, all contribute to saving
              energy and natural resources
        •     Zero waste program- Present practices of steel plant waste management
              vis-à-vis best practices, Envisage new products from wastes, their market
              scope, project cost estimate for implementation, preliminary evaluation of
              order of investment and running cost of implementation of a feasible
              technology.
        •     R&D opportunities:- Technology development efforts required to be carried
              out with special context to the wastes from steel plants
Present Practices – An Overview                                                   [1.1 / 6 ]


4.1 Waste Auditing
    A waste audit:

     •     Defines sources, quantities and types of wastes generated;
     •     Identifies where, when, how and why these wastes are produced;
     •     Identifies areas of wastage and waste problems; and
     •     Establishes targets and priorities for waste reduction.

     The waste audit can be used to:

     •     ensure external regulatory compliance;
     •     develop base-line data; and
     •     evaluate alternatives to minimize wastage of resources

     To conduct a waste audit, the following steps may be followed:

     •     List all generated wastes
     •     Identify the composition of the waste and the source of each substance
     •     Identify options to reduce the generation of these substances in the
           production or manufacturing process
     •     Focus on wastes that are most hazardous and techniques that are most
           easily implemented
     •     Compare the technical and economic feasibility of the options identified
     •     Evaluate the results and schedule periodic reviews of the program so that it
           can be adapted to reflect changes in regulations, technology, and economic
           feasibility.

4.2 Yield Loss in the Steel Industry
      From the available information, in a typical year, the U.S steel industry consumes
approximately 120 million tonne of raw materials and ships approximately 100 million
tonne of products. Roughly 53% of these shipments are produced by integrated
steelmakers, i.e. blast furnace and BOF operators, and 47% via the electric furnace
route. This represents a total yield loss of about 20 million tonne each year. The losses
are realized throughout many different operations in a steel mill. They appear in the
form of “home” scrap and waste oxides; integrated producers also lose a small
percentage of coal and coke. Yield losses also reduce the overall energy efficiency of
steelmaking. The steel industry consumes about 18.1 million Btu per ton of product,
22% more than the practical minimum energy consumption of about 14 million Btu/ton.
These energy losses – about 4 million Btu/ton – are a result of the energy “embedded”
in yield losses and process inefficiencies. Additional losses are generated in the use of
Present Practices – An Overview                                                  [1.1 / 7 ]


steel as it is manufactured into steel products. Examples of these “intrinsic” losses are
excess scrap generated because of quality rejects, poor or inconsistent steel properties,
or corrosion; excess material consumption due to excessive corrosion and safety
factors; the misapplication of materials; and manufacturing rejects and excesses from
manufacturing operations.
     For example yield loss improvements can be achieved through use of dusts,
scales and sludge as an input material in converter process but it has its own merits &
demerits.

5.    What Steel Industry should do for yield loss improvements
      The steel industry should strive to make improvements in yield losses in order to
become more competitive through better waste management. Yield loss in steelmaking
is a function of waste oxide production, slag formation, and in-plant scrap returns. In
addition, any off-specification steel that may be returned from the customer will be a
substantial yield loss. Finally, the yield loss associated with the use of finished goods
cannot be ignored; improvements in steel processing techniques that improve steel
quality and the development of new materials and their implementation by customers
have the potential to save up to substantial amount of energy required to manufacture
the steel used in the product.
     The steel industry needs more precise knowledge of steelmaking processes, feed
stocks, and products in order to address the complex combination of inefficiencies that
lead to yield losses. Better understanding and control of iron making and steelmaking
manufacturing processes will help reduce these inefficiencies. Advanced technologies,
operating practices, and materials that increase steelmaking productivity and yield will
also generate sizeable energy savings.
     Improvements in operating techniques and practices can reduce the yield losses
associated with in-house scrap returns, waste oxide production, excess slag formation,
lower throughput, and reworking. In-house scrap and the produce that returns due to
non conformity of specifications from customer must be reprocessed. Both kinds of
scrap represent significant yield loss since the energy consumed in the production of
these is lost.
     The operation of electric arc furnaces, for example, presents an opportunity for
improving yield by optimizing charging practices, reducing furnace heat time, and
optimizing operating cycles. The productivity of many finishing processes can also be
increased by minimizing process times and adopting practices that reduce defects.
Other examples are scaling due to improper atmosphere control and excess soaking
time in the reheat and annealing furnace. Lack of chemical control produces excess
slag volume and iron losses in the blast furnace, BOF, and EAF.
Present Practices – An Overview                                                  [1.1 / 8 ]


5.1 A Step Towards a Zero Waste Plant
     Globally, steel industry has made tremendous efforts in the past decade to
drastically reduce its operating costs and to comply with environmental requirements.
Given this situation, the promotion and acceptance of a "zero waste" philosophy in
environmental circles may appear to be an unwelcome challenge for the industry,
involving more up front exploratory work than continued operation with a pollution
control/compliance philosophy.

5.2 The Zero Waste Concept
    A zero waste approach should -
     1.    Be a structured approach to minimize -waste generation, energy
           consumption, emissions
     2.    View wastes & emissions as potential raw materials to be conserved or
           reused rather than wasted.
     3.    Clearly identify appropriate manufacturing processes and ensures bottom line
           cost savings.
     4.    Implement the identified projects which
           •     reduce process wastes,
           •     convert waste to economically beneficial material
           •     develop new processes that eliminate waste.

           For example, the value of EAF steelmaking slag is greatly increased if it is
           modified for use in cement-making operations.
           Redesign or develop a process which produces no unusable by products. For
           example, the COREX iron making process eliminates the need for coke
           making and coke oven gas byproduct recovery plants.

5.3 Potential Zero Waste Process for the Steel Industry
      Economics for every plant is uniquely determined by its location, age, product mix,
equipment, cost structure among other factors. It is neither reasonable nor economical
to attempt to make every process within a steel plant into a zero waste process, since
the thermodynamics and kinetics of some reactions mitigate against achieving absolute
zero waste.
     Some zero waste approaches and technologies in these areas are provided below.

5.4 Coke making
    •   Waste can be minimized by improving up the operation and maintenance of
        existing processes.
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     •     Zero waste option to develop new coking processes that reduce emissions at
           the source.
     •     Non-recovery coke making processes are technically viable for a lower quality
           of Coking coal.
     •     The combination of COREX and a Non-Utility Generator NUG is a reasonable
           option in areas with an inadequate power supply grid

5.5 DRI Production
     Iron oxide fines generated during the screening of ore and pellets are a process
waste for which there is no current economic use. Many DRI plants buy pellets and it is
not economical to return fines to the pelletizing plants that supply their raw materials. A
DRI technology that uses iron ore fines is a zero waste complement to the two DRI
technologies widely used. There are several processes like the DIOS coal based
process (Japan) uses iron ore fines, which are pre-reduced in a fluidized bed, to
produce liquid iron from a bath smelting reduction process. The FIOR natural gas based
process (Venezuela) uses 100% fines in a multiple stationary fluidized bed. The Lurgi
Circofer (coal based) and Circored (hydrogen based) processes use iron ore fines to
produce DRI.

5.6 Slags
    •   Evaluation of slag reuse is a low cost, high value option for steel plants.
     •      Opportunities for waste minimization include the reduction of slag volume
           through better control of lime input to the furnace and improved control of
           silicon and sulphur in blast furnace hot metal.
     •     The technology for reducing slag volume and increasing its value to other
           industries exists. It is dependent more on steelmaking chemistry and
           operating practices than on capital investment
     •     Blast furnace slags are used for the manufacture of cement, road base,
           railroad ballast, light weight concrete block, glass and artificial rock. Recycling
           it to the blast furnace may raise the hot metal phosphorus content to
           undesirable levels.
     •     The processing of steel slags for metals recovery is important for reuse at the
           steel plant and is also important to facilitate the use of the nonmetallic steel
           slag as construction aggregate.
     •     Slag processors to be developed in the vicinity to handle a variety of
           materials such as steel slag, ladle slag, pit slag, and used refractory material
           to recover steel metallics.
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     •     segregate spent refractories at the source of generation, use them for less
           critical applications after necessary conditioning and use them as constituents
           in manufacture of new bricks/mortars

5.7 Hot Rolling
     The hot rolling operation generates scales and sludges with high iron content,
contaminated with significant amounts of oil and grease.
     The zero waste approach in this area may have three elements:

     •     Minimize Scale Generation. Direct rolling or hot charging and good reheat
           furnace
     •     management can reduce scale loss.
     •     Reduce Oil Contamination: One of the primary sources of oily scale is
           leaking bearings. Reductions in oil losses through the use of sealed bearings,
           thus reducing maintenance, operating costs, and the quantity of oil in sludge.
     •     Oil Separation. Oily sludge is slurry of water, oil and metallic which is difficult
           to separate. It has been significantly demonstrated by North American Steel
           Industry improved separation of the constituents can be obtained using
           microwave technology and specially developed oil release agents.

6.   R&D opportunities in Waste Management in Steel Industry
     The steel industry can improve its fuel efficiency and productivity by capturing the
heat value of by-product gases and optimizing its mix of fuels and feedstock. In a similar
fashion, efficient use of iron and steelmaking by-products can improve yield by
maximizing the industry’s use of its iron-bearing feedstock. Recycling scrap may
consume less than half the energy required for iron ore reduction. R&D to increase
recycling includes improved measurement technologies to classify scrap and
processes.
      The reliance of iron making on coke is a productivity barrier that can be overcome
by increased use of coke alternatives such as coal and natural gas. Research have
shown Iron-bearing by-products generated within the steel mill can also be used as
feedstock to the blast furnace. Waste oxides contain iron units plus lime, coal and coke
fines.
     Research leading to increased internal recycling of these residues will increase the
steel industry’s primary yield while reducing disposal costs and saving energy.
Advanced refractories and other improved materials can reduce the frequency of both
scheduled and unscheduled downtime for furnaces and ladles. The development of
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rolling and finishing technologies with reduced maintenance requirements or faster
operating speeds can eliminate bottlenecks that inhibit productivity in these stages.
     R&D in the Material properties can optimize steels in ways that minimize the yield
loss in manufacturing. For example, appropriate alloying, rolling, and heat treating
practices must be determined as well as weld ability, forming, and annealing schedules.
     R&D opportunities to improve microstructure control and reduce defects include
better sensors for chemistry, cleanliness and defect detection systems. Half of the
Waste oxide generation in steelmaking furnaces contains iron. A major barrier to
reducing this loss is maintaining reliable process control and furnace stability. Potential
R&D opportunities to overcome this barrier include sensors for critical chemical and
physical parameters in the BF, BOF, and other furnaces; real-time chemistry adjustment
technologies; and advanced combustion control systems.

6.1 Viewpoint
     It is proposed that to ensure Zero Waste in steel industry, waste management
departments should be created mandatory in every steel industry and then steel
industry should have an apex body comprising of personnel of waste management
department/environment/safety with a mission to promote steel as the material of choice
and to enhance the competitiveness of steel industry by targeting for sustainable waste
management programmes through more and more R&D in this area with an ultimate
aim for zero waste implementation in steel industry.
     As part of its strategy for achieving the goals, the body should create an extensive
high-risk R&D program to develop new technologies and reduce the lead time between
discovery and commercialization. The program should be highly leveraged by steel-
producing companies, steel users, and equipment suppliers. Because the waste
management apex body R&D accomplishes a public purpose as well as the industry’s
objectives, the local/central Government may share cost of the R&D projects taken up
by this body. The other part of the strategy of this body should be to ensure the
implementation of Zero Waste program.
     The waste management apex body and steel companies in individual capacity and
Steel sector as a whole will share several common goals, including maintaining a
globally competitive manufacturing sector, increasing energy efficiency, reducing
environmental impact, and creating and saving jobs.
    The numerous benefits of this collaborative partnership of the industry and
Government are summarized below.
     •     Increasing Energy Efficiency and Improving the Environment:
     •     Leveraging High Risk Research
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     •     Maintaining Globally Competitive Manufacturing
     •     Delivering Safe, Low-Cost Consumer Goods
     •     Utilizing Government Resources and Expertise
     •     Accelerating Technology Development

     Based on the discussions in this paper some of the key R&D Opportunities that
may be taken up for Yield Improvements by the industry are given below. The lists of
opportunities are not meant to be exclusive; rather, they are representative of the kinds
of activities that could be included in the overall pathway for yield improvements.
     •     Modeling, Measurement, and Control
     •     Operating Techniques and Practices
     •      Process Equipment
     •     Fuels, Feedstocks, and Recycling
     •     Material Properties and Manufacturing Technologies


6.2 Zero Waste Implementation
     Waste minimization and recycling is widely perceived to require more initial
exploratory work. An organized approach to waste minimization is required to identify
and economically justify opportunities to reduce environmental costs and/or make a
valuable product from waste.
     A zero waste program will be successful only when it has five key factors:
     1.    Total commitment from the highest levels of management.
     2.    Cross discipline teamwork.
     3.    Clear-sighted identification of areas which provide environmental and
           economic opportunities.
     4.    Objective process evaluation.
     5.    A continuous improvement outlook.

7.   Conclusion?
     Waste Management requires a new attitude. Traditional thinking places all the
responsibility on a few experts in charge of for it. The new focus shall make waste
management everyone's responsibility. Waste management may be a new role for
production-oriented managers and workers, but their cooperation is crucial. It will be the
workers themselves who must make waste management succeed in the workplace.
     Management commitment and employee participation are vital to a successful
waste management program. Management can demonstrate its commitment to pollution
prevention and encourage employee participation by:
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     •     Training employees in waste management techniques
     •     Encouraging employee suggestions
     •     Providing incentives for employee participation
      •     Providing resources necessary to get the job done.
      Waste management projects may be selected & strategies developed for new
installations right from the design stage during the expansion/modernization going on in
the Steel industry.A systematic approach will produce better results than piecemeal
efforts. An essential first step is a comprehensive waste audit. Areas that pose a
significant problem with respect to environmental compliance and/or costs are good
places to start.
     The zero waste concept can be applied to both integrated and mini-mill steel
plants. Waste Management does not end with project implementation, follow-up and
continuous improvements are crucial to waste management. Measurement and
reporting of waste reduction and cost saving goals achieved will help to justify future
projects and indicate areas for further work.
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                   ZERO WASTE JOURNEY AT ESSAR STEEL
                                      Dr. A.K Das
                                  Senior Vice-President
                                   Essar Steel Limited

1.   Introduction
     Essar Steel Ltd., Gujarat (India), is part of the Essar Group of Companies which
has established roles in other fields like Shipping, Oil, Power, and Communication. It is
involved in manufacturing of Hot Briquetted Iron (HBI) and Hot Rolled Coils (HRC),
through the ‘Direct Reduced Iron (Hot Briquette Iron) – Electric Arc Furnace (DC) –
Ladle Furnace – Vacuum Degassing / Vacuum Carbon Deoxidation - Continuous Slab
Caster – Hot Rolled Coil – Cold Rolling - Galvanizing’ route at its Hazira operation 1.
The steel plant generates by-products such as slags, fines and dust. Essar steel is
aiming to achieve the status of a “Zero Waste Company” through recycling and reducing
the by-product generations.

2.   Global trends of waste utilization
     The iron and steel industry represents one of the most energy intensive and waste
generative sectors within the Indian economy and is therefore of particular interest in
context of both local and global environmental discussions 2. The present day scenario
demands a balance in the productivity as well as the reduction in the wastes expelled
from the Industry. Hence there is a great drive among steel giants as to find a way for
proper utilization of various wastes and energy in order to maintain a “clean sheet” in
the global market.
     Scrap is one of the primary waste materials which are now being effectively
recycled. Recycled iron and steel scrap is a vital raw material for the production of new
steel and cast iron products. Recycling of scrap plays an important role in the
conservation of energy because the remelting of scrap requires much less energy than
the production of iron or steel products from iron ore 3.
      Blast furnace flue dust is a solid waste material from the integrated steel plant. The
flue dust is a mixture of oxides expelled from the top of the blast furnace, whose major
components are iron oxides and coke fines. It also contains silicon, calcium, magnesium
and other minor elemental oxides in lesser amounts. The direct recycling of flue dust is
not usually possible since it contains some undesirable elements (like zinc, lead and
alkali metals) that can cause operational difficulties in the blast furnace. As these
undesirable elements are in very low quantities it is not economically feasible to extract
them on an industrial scale.. The same is seen in Electric Arc Furnace dust also called
Fume Extraction System (FES) dust, which contains a large amount of iron oxide.
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These dusts are first processed for extraction of zinc and other metals (if scrap is used
during charging) and later pelletized. Research has found that it could be used as a
source of lime and phosphorous in fertilizers.
     Slag produced during the processing of iron and steel poses risk as its utilization
possibilities are limited. Blast Furnace slag, due to the lower iron content and its glassy
nature has found bulk use in the production of slag cement and pozzolanic cement 4.
Basic Oxygen Furnace (BOF) slag has the useful components like CaO, MgO with high
basicities (CaO/SiO2) of above 3.0. BOF slag therefore has high fluxing capacity and is
being charged in the blast furnace due to easy melt and better utilization of calcium
values. In the European countries, 30% of such slags are recycled into the blast
furnace. However, the most harmful components in the BOF slag is Phosphorous
which needs to be accounted for before use either in sintering plant or blast furnace.
      Electric Arc Furnace (EAF) slag owing to its high crystallinity and high iron content
has presently no well established method for potential recycling. The Basicity Index (BI)
of the slag is generally between 1.2-1.8 which comes under the low hydraulic Merwinite
group. Also the Grindability Index, which is a measure for the energy required for
grinding a particular material to a given size, is high due to high Iron oxide content. This
makes the further grinding and processing of EAF slag energy intensive. Research is
presently focused on investigating the partial replacement of clinker with EAF slag for
the production of slag cement. Some other researchers have tried to substitute standard
sand with EAF slag and have reported benefits like increase in the compressive
strength and lower consumption of water. Ecomaister Co. Ltd. of Korea has invented,
patented and commercialized Slag Atomization Technique (SAT) by means of which
molten slag is converted to small round balls which is later used as a blasting material
or in cement admixtures 5.
     Most of the materials of sludge and dusts from steel industries are recycled
through sinter making. The recycled wastes also have some effect on sinter quality,
strength and productivity. The recycling is generally controlled depending on the
analysis of the waste material.
      The process byproduct of mill scale from the rolling process containing >70% Fe is
generally recycled into the sintering plant. Generally, 70–100% mill scale containing
high iron is being recycled through either briquetting or sintering route with out any
difficulties. In some cases, de-oiling of the material is required. Rolling mill sludge
contains fine particles, which take the oil portion along with the rolling cooling water.
Recycling of these particles are challenging due to very high oil content. The reduction
of oily mill scale sludge along with blast furnace flue dust in laboratory experiments and
in a pilot plant rotary kiln has indicated that it is possible to reduce oily mill scale sludge
to sponge iron in the rotary kiln.
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3.   Scenario at Essar Steel
     Essar Steel Ltd. With a current capacity of 4.6 million tones per annum, generates
various materials as by-products from the steel melting plant and other plants. Some of
the major by-product generations are given in the Table 1. Electric Arc Furnace slag
and Ladle Furnace slag are the predominant by-products that need immediate attention.
Understanding this, the management as well a key professionals have focused their
attention and also have chalked out several projects for their effective utilization.
                     Table 1: By-product generation at Essar Steel Ltd.
                                                            Source of
            By-product
                                                            Generation
            Lime fines                                      Lime plant
            Dolime fines                                    Dolime plant
            Slag (Electric Arc Furnace & Ladle
                                                            Steel Making Plant
            Furnace)
            Fume Extraction System Dust                     Steel Making Plant

4.    Waste utilization at Essar Steel
      A Sinter plant with a capacity of 1.32 million tons located on an area of 120 m2
has been commissioned. The main function of this plant would be to sinter the iron ore
fines generated from the calibrated lump ore degradation as well as from the broken
pellets. A 12 ft diameter disc pelletizer is a part of the plant. Essar is planning to utilize
the sludge pond fines, mill scale and fume extraction system dust for making
micropellets using this pelletizer and hence increase the amenability for these materials
to sinter. The sinter produced would be then utilized for making hot metal in the blast
furnaces and later charged in the Electric Arc furnaces.
       EAF slag generated at SMP after necessary characterization with respect to the
chemical and physical properties has been effectively utilized for filling the low lying
areas in and around the plant. The slag has also been used as an effective aggregate
for road making within the plant premises as well as in surrounding areas. Trials have
been completed in joint collaboration with Surat Municipal Corporation and Reliance
Industries Ltd. Essar has also initiated collaborative research work along with Central
Glass and Ceramic Research Institute (CGCRI) Calcutta to make vitrified ceramic
tiles from the slag. Prototypes have been prepared; field trials of the tiles will be taken
up shortly. Trials of recycling ladle slag as a source for lime is also being carried out.
Characterization studies of Fume extraction system dust is being carried out to find
other potential route for its recycling/reuse.
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      Steel Making Plant (SMP): SMP generates various by-products such as scraps,
skulls, lime fines, dolime fines, slag and Fume Extraction System (FES) dust. Scrap,
skulls, all metallic wastes are directly being utilized/recycled for use in the Electric
Arc Furnace for steel making.
      Lime fines generated during lime making process are binded along with
pulverized coal and fed to the Electric Arc Furnace. Trials of making pellets out of lime
fines and pulverized coal has been completed. These pellets will be part of the feed mix
to Electric Arc furnaces. Slurry made from lime fines is also used to coat pellets
before charging in the Hot Briquetted Iron (HBI) modules to prevent clustering at high
temperatures inside the module during operation.

5.   References
     1. “Electric Arc Furnace (EAF) Slag - An excellent substitute for materials of
         construction in Essar Steel Ltd” – Internal report, Essar Steel Ltd.
     2.    B.P.Radhakrishna, “Boom in India’s Iron and Steel Industry”, Current Science,
           Vol: 92, No.9, May 2007.
     3.    Michael Fenton, “Iron and Steel scrap”, U.S Geological Survey, Mineral
           Commodity Summaries, January 2003.
     4.    B. Das, S. Prakash, P.S.R. Reddy and V.N. Misra , “An overview of utilization
           of slag and sludge from steel industries”, Resources, Conservation and
           Recycling, Volume 50, Issue 1, March 2007, Pages 40-57.
     5.    “Slag Atomizing Technology (SAT): Strategic management of electric arc
           furnace slags”, Global Slag Magazine, June Issue.
     6.    Luckman Muhmood, “Slag utilization possibilities at Essar”- Internal Report,
           Essar Steel Ltd.
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               NEED FOR INDIAN IRON AND STEEL INDUSTRY
                                   R.K. Agrawal & A.Sengupta
                                  E-mail: sailemd@rediffmail.com



                                            Abstract

        Indian steel industry is, though nearly 100 years old, has not been able
to cross the crude steel production figure of 100 MTPA even though the country
has vast reserves of iron ore, coal and other minerals. Of the total crude steel
production around 45.1 MTPA (2005-2006), nearly 49% production is from primary
steel producers and balance 51% from secondary steel producers. With the total
liberation of industry sector since 1990s, the country is aiming to achieve 100
MTPA crude steel production within a span of 12 to 15 years, based on clean
technologies, at par with the world standard. A large number of new process
technologies for iron making is presently available in the world, particularly in the
developed countries. The relevance of these modern clean technologies with regard
to the conventional technologies and their feasibility for introduction/adoption in
India have certain limitations in Indian conditions:-
     Absence of suitable technologies for beneficiation of Indian raw materials ,
specially iron ore and coal, Tata Steel has adopted their coal beneficiation
technology to bring down ash level to 14%; but more reduction is required. Coal,
based DRI is forced to use high ash coal of 25 to 40%. VM content in coal is
high and fixed carbon in coal is low . Hence, they are limited to be used even in
the alternate clean route of iron making by COREX process in India.
      Several Indian steel plants have adopted some of the modern technological
innovations such as pre and post-carbonisation techniques. Stamp charging for
coke making as well as partial briquetting are also being tried to use inferior
quality coal. Non-recovery coking with heat recovery is finding nowadays much
preferred option. Jindal Steel also has installed Non Recovery type coke oven.
     As most of Indian iron ores are combination of hematite-goesthite and
hematite-limonite, the sintering technology has to be developed for high fusibility
characteristics of iron ore. Energy efficient sintering process technology having
least emission is in demand. India requires low capacity cost-effective pelletisation
plant.
     For iron making, in Blast Furnace area, coke rate has been brought down to 475kg
/thm from earlier 550 kg/thm. This is an important area for Indian steel plants as
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coking coal stock is very limited. Technological innovations on BF are continuing by
modernisation. In the secondary sector, DRI (Direct Reduced Iron) based steel Plants
are coming in the area where coal and gas availability is abundant. To day India is the
highest producer of DRI in the world. Jindal’s COREX plant is one of the pioneers of
Iron making by smelting reduction process.
     In the steel making process, many technological development have been taken
place through out the years including secondary refining, still a lot more to be done to
be competitive in the world. On line sampling of steel, installation of secondary de-
dusting facilities, maximising continuous casting, etc are the emerging trend now.
     Electric Arc Furnace Steel Making sector, there is wide variation in the
technological profile . Few Indian plants are of world class but others still suffer
with technological obsolesces . Electrode consumption of the order of 1 kg/ton
needs to be adopted. Fume emission control devices need improvement in
accordance with national environment policy-2006.
     Steel makers around the world are switching over to continuous casting. In India
Steel Production through continuous casting route is only 66% which is much less
compared to the world average of 91%. India also need to enhance the continuous
casting facility, Thin Slab casting etc. Utilisation of Rolling Mills sludge and oily Mill
Scales also need to be increased .
      For Energy/GHG Emission Reduction, Energy Audit for all the plants has become
almost mandatory. All the steel plants, particularly, primary steel producers, are
striving hard to bring down the energy consumption level by waste heat recovery
from all the practicable sources . Energy savings has government bearing on the
operational cost of the plant. The report of the expert committee on integrated
energy policy of planning commission has recommended for creation of national
energy fund to finance energy research and development which inter alias include
technology up gradation as well as to reduce energy and GHG emission.
      In accordance with the National Environmental Policy-2006 and for the
sustainable growth of the society, Indian steel industry being one of the core
contributors towards GDP, technological-cum-financial assistance are needed in
some of the key areas like quality improvement of prime raw materials, utilisation of
inferior quality of raw materials, dust pollution reduction to a level of 1 kg per ton of
crude steel or even below, SOX /NOx pollution reduction to a level below 1.2 to 1.5
kg per ton of crude steel, complete treatment of phenol, cyanide, ammonia and
other eco-toxic materials from the wastewater of the steel plant, comprehensive
energy recovery and GHG emission reduction.
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   KEY WORDS: DRI, COREX, STAMP-CHARGING, NON-RECOVERY COKING,
GHG, TRT, CONARC, CONTIARC, SCOPE-21, COKE DRY QUENCHING, CDI,
CREP, EAF

1.    Introduction
      Steel in its many forms plays a crucial role in shaping modern industrial society. It
is a decisive factor for the economic and social development of our global society.
However, in this global and highly competitive environment, we have to continue our
efforts to produce steel at less cost, fulfill the stricter quality demands and find solution
to the limitations of energy and raw materials as well as environmental constraints.
      A time existed when there were limited options for producing liquid steel. This
situation has changed with recent technological advancements. Many technological
routes have been identified for making hot metal at different parts of the world to avoid
high capital cost of conventional Blast Furnace and make use of different types of
available raw materials to produce steel at lesser cost - depending on the regional
advantages, market demand and techno - economics. While many processes are under
pilot or demonstration scale, few of them have come up as commercial plant.




2.   Current National & International Scenario

    Global crude steel production during the year 2006 accounts to 1240 Million
Tonnes, which shows a growth of 8.8 % over 2005. China accounted for most of the
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incremental production. Further growth in Production / consumption is expected to
come from BRIC (Brazil, Russia, India & China) countries. Cost / availability of raw
materials (mainly iron ore & coal ) are areas of major concern. India is the 7th largest
steel producing country in the world with crude steel production of 45 MT in 2006.
     In India, the producers of Iron and Steel have been divided into two broad sectors,
namely the Primary and the Secondary, depending on the technological process used in
production. The sectors using the various routes are given below:
     1.    Primary Sector - Coke Oven - Blast Furnace - Basic Oxygen Furnace
     2.    Secondary Sector - Scrap based Electric Arc Furnace (EAF) steel making
     3.    DRI based EAF steel making
     4.    Mini Blast Furnace based plants
     5.    Induction Furnace ( IF)based plants

     At present, the primary sector consists of public sector integrated steel plants
under Steel Authority of India Ltd. (SAIL), Rashtriya Ispat Nigam Ltd. (Vizag Steel Plant)
and the private sector Plant of Tata Steel. In the secondary sector, major steel is being
produced through the Electric Arc Furnace route with some of the new generation plants
having captive DRI (Direct Reduced Iron) & COREX facilities. In addition, there are a
couple of induction furnace units for producing steel ingots. There are a few lone DRI
producing units also, who produces sponge iron as input material for the Electric Arc
Furnaces as substitute for scrap.
       While the integrated steel plants in the primary sector have downstream rolling
facilities, the secondary sector has innumerable small, medium and large rolling
facilities which produce finished steel, using feed materials of semis from the primary
sector, EAF and IF units. However, there are many Induction Furnace and Electric Arc
Furnace units who have there own downstream rolling facilities.
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     Crude Steel Production in India shows an exponential growth in last few decades
which shows more than 100 % increase of production in last 10 years.




     Growth in steel demand is highest in developing world. In India present per capita
consumption of finished steel is 30 kg/annum compared to world’s average of 170 kg
/annum. Per capita consumption in India shows a growth of about 46% in last 7-8
Years. The reason for increase in demand is due to more urbanisation and subsequent
change in life, style. This has subsequently lead to infrastructure development, demand
in automobiles and transportation sector.

3.    Raw Materials
      Major raw materials used for Iron & Steel making industry are iron ore and coking
& non-coking coal. As per National Steel Policy, to produce 110 million tonnes of steel
by the year 2020, iron ore & coal (coking & non- coking) requirement will be around 190
million tonnes and 100 million tonnes, respectively. Keeping this in mind, review of our
raw material resources, particularly iron ore and coal have gained utmost importance.
Though India has abundant reserves of iron ore, beneficiation of ore to improve the
quality and increased recovery of Iron Ore fines are necessary for effective &
sustainable use of the resource. For this, various techniques like use of hydro-cyclones,
flotation, magnetic separation, jigging etc., can be used. Indian mining industry requires
modern washing and beneficiation techniques for effective utilization of our resources.
     Presently most of the fines generated in Indian mines are being exported or
stocked at the mine site, as there is no demand from the Indian steel industries.
Pelletization of these fines can be done for direct use of fines as a feed material for iron
making. In the pelletization process, the iron ore fines are initially agglomerated into
green pellets by adding a binder, usually powdered bentonite. The green pellets are
hardened by drying & heating in an oxidizing atmosphere in the furnace / kiln. India
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needs low capacity pelletization plant for effective utilization of ferruginous wastes like
iron ore fines / dust etc.




      India has also huge coal reserves, but significant portions of the coal reserves are
characterized by high ash content. The estimated coking coal reserves in India is only
32 billion tonnes which is about 13% of the total coal reserves of our country, and
having high ash content. Hence Indian steel industry are mostly dependent on import of
coking coal, containing low ash. For effective utilization of the Indian coal reserves, high
efficiency coal beneficiation and washing methods are required which includes cleaning
of coarse coal in Jigs, Barrel or Heavy Media Bath and cleaning of fine coal using
flotation technique or Cyclone /Hydro cyclones, with closed circuit water recovery. This
will not only improve the utilization of the Indian coal but also reduce the dependency on
the import as well as less environmental problems.

4.   Coke Making
     Most of the recovery type Coke Ovens of Integrated Steel Plants in India (except
few like RINL) were set up during 1950s to 1970s and were subsequently expanded
and modernized. During those days, the pollution control facilities were installed
basically aiming at process requirements rather than control of pollution. There were no
emission/ discharge standards except the standard of CO emissions (3 kg/ton of coke)
and Stack PM emissions standard. (50 mg/Nm3). In 1997, Govt of India notified the
Present Practices – An Overview                                                 [1.3 / 7 ]


environmental standards for coke making. Subsequently there was a Industry
Regulatory Authority charter on CREP (Corporate Responsibility for Environmental
Protection) which emphasizes on the fugitive emissions control from Coke Ovens and a
specific time bound rebuilding target of the batteries.
      In due course of time, several other technological developments and initiatives
have been taken place in Indian steel industries for the manufacturing of coke.
However, for rebuilding, due to absence of indigenous Coke Oven designers and the
equipment / technology suppliers, Indian coke makers are facing difficulty in achieving
the time bound rebuilding target.
     Most of the phenolic water treatment plants (BOD Plants) are facing problems in
meeting the effluent discharge quality standards. These units also need revitalisation
keeping in view of the existing regulations. However shifting from wet quenching to dry
quenching serves the dual role of energy efficiency and pollution control. Emerging
technologies for coke making with less impact on environment & energy efficiency
includes Coke Dry Quenching, Stamp Charging , Taller Coke Ovens Battetries, Scope -
21 Process etc.

4.1 Coke Dry Quenching
     CDQ charges hot coke produced in a Coke Oven into a chamber by lifting device
and cools it with circulating gas (inert gas) which is heated to the temperature of 900-
950oC by heat exchange with hot coke. This heated circulating gas, after passing
through the primary dust removing device, is conveyed to a boiler to generate steam.
Approximately 0.58 tonnes of steam per tonne of coke is generated in the boiler, and
the steam is supplied to the steam network power generation system for power
generation. Circulating gas is cooled down to around 200oC in the boiler and then
recycled into the chamber to quench the next shift of hot coke. CDQ (Coke Dry
Quenching) facility exists in Rastriya Ispat Nigam Limited- 3 MTPA Plant in India and is
giving satisfactory result. However most of the new Coke Plants at green field sites are
planning for CDQ installations in future.

4.2 Stamp Charging Of Coal Charge
      Stamp charging is a process where the entire coal charge to the coke oven is
stamped or compressed and then pushed into the oven for coking. It is one of the
effective way of densification of coal charge. The stamping process brings the coal
particles into more intimate contact with each other which enhances the coking
property. This technology has tremendous potential for improving the coke quality for
inferior coking coal. In India, TATA Steel has Stamp Charged Batteries.
Present Practices – An Overview                                                [1.3 / 8 ]




4.3 Scope- 21 Process For Coke Making
      This is innovative coke making, developed by Japan, allows greater use of poor
quality coal and provide higher productivity and less polluting coking process.
    Keeping in mind, the demand and supply of coal, it is anticipated that there may be
a shortage of quality coal, unless a new economically viable and environmentally
acceptable coke production facilities are installed.
      However, application of this technology in India needs further research depending
upon the quality of Indian coal and quality of coke in demand in the down stream of
steel making process.
     SCOPE -21 eliminates the problems of limited choice of coal sources, associated
environmental pollution and high energy consumption in conventional recovery type
Coke Ovens.
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4.4 Non Recovery Type Of Coke Ovens
     Large scale Non Recovery Coke Plants are not much prevalent in India. except at
Jindal Steel Works, at Karnataka. However, this technology is being considered by
number of coke makers during future installations in the green field areas.
     In the areas of coke making, technology transfer is solicited in the areas of coke
oven rebuilding / design, modern and improved design of battery machines, pushing
and charging emissions control, improved askania control, modern quenching tower
with quenching emissions measurement facility, facilities for smooth functioning of BOD
Plants etc.

5. Sinter Making
       Sensible heat recovery from the main exhaust gas from the Sinter Machines and
Sinter Coolers have got great potential for energy conservation in steel plants. This
facility is available in some of the new generation Sinter Plants in India, however, Sinter
Plants of first generation (1960- 70s) are unable to recover this sensible heat due to
logistics and space problems. A suitable technology/design supplier for retrofitting the
same in the existing layout would definitely yield less pollution and less energy cost for
steel production.
     Effective utilisation of iron bearing dusts and sludge by agglomeration process
using rotary hearth furnace has been developed by Japan. The pellet produced in this
process can be directly fed as sinter feed or directly in Blast Furnaces.




6.    Iron Making
      Iron Making through Blast Furnace route includes capital cost for a new Coke
Oven Plant and a new Sinter Plant. To avoid such high capital investment and to utilize
low grade coal and iron ore fines. Alternative iron making technologies have had been
tried and tested in India and were found successful. Some of the alternative Iron making
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technologies are through Direct Reduction, Smelting Reduction along with combination
of EAF or BOF for production of steel.

6.1 Direct Reduction Processes
     Presently India ranks 1st, amongst the producers of DRI, with an annual production
of 15 MTPA, (25 % of the world out put) followed by Venezuela 8.6 MTPA and Iran 6.9
MTPA.
     India’s Ispat Industries Limited (IIL) is one of the leading integrated steel makers
and the largest private sector producer of hot rolled coils in India through DRI process. It
produces world-class sponge iron, galvanised sheets and cold rolled coils, in addition to
hot rolled coils, through its two state-of-the art integrated steel plants, located at Dolvi
and Kalmeshwar in the state of Maharashtra. It’s 1,200 acre Dolvi complex, houses the
3 MTPA Hot Rolled Coils Plant, that combines the latest technologies - the Conarc
Process for steel making and the Compact Strip Process (CSP) - introduced for the first
time in Asia. The complex also has a 1.6 MTPA Sponge Iron (DRI) Plant, which was
commissioned in 1994 as the world's largest and most efficient gas-based single mega
module plant. Moreover, the Dolvi complex has a 2 Million Tonne Blast Furnace. Ispat is
the only steel maker in India and amongst a few in the world to have total flexibility in
choice of steel making route, be it the conventional Blast Furnace route or the Electric
Arc Furnace route. Its’ dual technology allows Ispat the freedom to choose its raw
material feed, be it pig iron, sponge iron, iron ore, scrap or any combination of various
feeds. It also has total flexibility in choosing its energy source, be it electricity, coal or
gas.

6.2 Smelting Reduction Process
      The new smelting reduction processes are based on the use of coal together with
pellets or lump ore. One objective of these processes is to eliminate Coke Ovens and
Sinter Plants. Another goal is to achieve non agglomerated fine ore. The smelting
reduction processes can be divided into two groups, the indirect reduction or “inbed”
process and direct reduction or “inbath” process, which includes COREX, HISMELT,
ROMELT, DIOS etc. Compared with the traditional hot metal production through Blast
Furnace route, only the COREX process offers the possibility of produceing hot metal
without BF quality coke on industrial scale. The operation results achieved from the
operating COREX plants at POSCO, SALDANHA and JINDAL STEEL, India confirm
this.
      JINDAL’s COREX Plant has 2C-2000 modules. Module -1 was commissioned in
August 1999 and Module -2 was commissioned in April 2001. This process has greater
flexibility in operation and uses various types of non-coking coals as a primary fuel and
requires raw materials of less stringent quality. The gas generated from the process is
Present Practices – An Overview                                                    [1.3 / 11 ]


used for power generation for the pellet plant and as a fuel in the integrated plant
complex. The special features of COREX hot metal are; high temperature (1480 - 1510o
C), low sulphur, low nitrogen and least amount of impurities. Finally, it is more eco-
friendly compared to the conventional Blast Furnace route due to exclusion of Sinter
Plant and Coke Ovens.




6.3 Conventional Blast Furnace Route
      In the field of Conventional Blast Furnace route, emerging technologies are direct
injection of reducing agents, energy recovery from top gas pressure, Cast House De-
dusting and Cast House Slag Granulation Plants etc.

6.3.1 Direct Injection Of Reducing Agents
      Direct injection of reducing agents (hydro carbons) in place of coke, in the furnace
at the tuyere level, reduces the need for coke, reduce overall pollution and energy
demand as well as avoid emissions at the Coke Oven Plant. Hydrocarbons may be in
the form of heavy fuel oil, tar, granular or pulverised coal, natural gas or plastic wastes.
Since coke acts as a mechanical medium as well, certain amount of coke is still
necessary to allow proper Blast Furnace operations.

6.3.2 Coal Injection
      Theoretical maximum rate for coal injection at the tuyere level is @ 270 kg/thm
For every kg of coal injected, approximately 0.85 - 0.95 kg of coke production is
avoided. At an injection rate of 180 kg/ton of hot metal, energy savings amount to 0.68
GJ/ thm or 3.6% of the gross energy consumption of the Blast Furnace. This saving is
Present Practices – An Overview                                                  [1.3 / 12 ]


achieved indirectly due to reduced coke consumption. The use of CDI along with
oxygen enrichment, saves coke and increases productivity of Blast Furnace.

6.3.3 Energy Recovery From Top Gas Pressure
     High top pressure Blast Furnaces provide an ideal opportunity for recovering
energy from the large volume of pressurised top gas generated by means of an
expansion turbine, which is installed after the top gas cleaning device. The electricity
generated is reported to be as much as 15 MW in a modern Blast Furnace with a top
gas pressure of 2 - 2.5 Kg / cm2. Energy saving is estimated up to 0.4 GJ/thm for a 15
MW turbine. SAIL, in its Corporate Plan 2012 has envisaged the installation of TRT in
new Blast Furnaces. For the old furnaces it has been planned during furnace up-
gradation/ relining, keeping in mind the logistics and space.




7.   Steel Making
     The performance of the technological routes of steel making in the steel plants of
our country is considerably inferior as compared to the technology at the advanced
countries. The inferior performance is due to the inefficient /obsolete use of technology,
mismatch of Indian input materials with imported qualities --- all leading to low
productivity of capital and labour.
     Though the production of steel through secondary refining has been increased
over years in India but the quantum has been comparatively low with respect to other
advance countries. Technology is crucial to long term competitiveness. Some of the
Cleaner technologies for Steel making are energy recovery from the BOF gas, on-line
sampling and analysis of steel, secondary de-dusting, dust hot briquetting & recycling,
treatment of wastewater from wet de-dusting and treatment of wastewater from
continuous casting.
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7.1 On -Line Sampling And Steel Analysis
      Oxygen steelmaking is a batch process. Every charge of pig iron has to be refined
until the required steel quality is achieved. In order to monitor progress, samples are
taken from the steel bath for analysis. The result of the analysis is used to determine the
additional time of oxygen blowing needed to achieve the required steel quality. In
modern plants, samples are taken on-line during oxygen blowing by means of sub
lance. This shortens production cycle times and so increases productivity. Emissions
are lower compared with the previous sampling method as the position of the BOF is
not changed. All modern plants apply on line sampling.

7.2 De-Dusting Of Secondary Off-Gases
     Sources of secondary off-gases result from reladling and deslagging of hot metal,
BOF charging, tapping of liquid steel and slag from BOF (Converters) and ladles,
secondary metallurgy and tapping operations handling of additives, continuous casting
etc.




      Until the early 70s, oxygen steelmaking plants were built without secondary dust
collection equipment. As a result, most of today’s secondary and subordinate primary
source dust collecting installations are retrofitted. The efficiency of such systems is
highly dependent on local conditions. These play an important role when it comes to the
choice and design of the recovery system (enclosures, hoods, etc). Determination of the
waste gas flow rates often depends on local conditions and on the available space for
installing piping systems together with the possible size of the pipe cross-sections.
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     As per the CREP charter, Ministry of Environment and Forests, all the integrated
steel producers to install secondary de-dusting facility at the Steel Melting Shops by
2008.

8.   Electric Arc Furnace Steel Making
      In the steel industry, the arc furnace is mainly used for the melting / refining of
steel which mainly eliminates undesirable components such as phosphorous, hydrogen
& oxygen from the material through different chemical reactions including
decarburization, dephosphorisation, desulphurization and de-oxidation, in order to
obtain the desired physical and mechanical characteristics while adjusting the major
components such as carbon so that steel with good qualities can be obtained.
     Through out the world, various arc furnace technology like Energy Optimizing
Furnace, CONARC, CONTIARC etc have been developed where the off gas from one
furnace can be utilized for pre-heating of other furnace.

8.1 Conarc
      Process combines conventional Converter process with Electric Arc steel making
in a furnace with two identical shells. The furnace is equipped with one set of
electrodes which are connected to transformer and can be slewed alternatively to each
of the two shells. Oxygen is injected through water cooled lance which also can be
slewed between the furnaces. The process is split into two processes, Converter
process during which the liquid iron is de-curburised by injection of oxygen and Electric
Arc process where electrical energy for melting of the solid charge and for superheating
of the bath to tapping temperature is used .


8.2 Contiarc
     Mainly consists of a melting reactor with an inner electrode, holding and guiding
system inside a central water cooled shaft, which serves to protect the electrode. In this
process the off gas from the furnace is used to preheat the charge .
      In the Indian context, there is a wide variation in the technological achievements in
the Arc Furnace Technology. There is limitation in the development of Electric Arc
Furnace Technology due to high energy cost and poor availability of scrap. However,
few secondary producers in India have done considerable progress (refer Ispat Industry
in the Iron making section) in this regard. Installation of proper secondary emission
control system, utilization of EAF dust & slag and control of high noise in the EAF
steel making processes have further scope of improvement . Electrode consumption
of Electric Arc Furnace need to be reduced to 1 kg/thm from the existing level of 6.1 –
6.9 kg/thm (Reference Plant: Alloy Steels Plant, SAIL) .
Present Practices – An Overview                                                    [1.3 / 15 ]


9.    ROLLING MILLS
      Ingot casting is an obsolete technology and steel makers all over the world are
switching over to continuous casting. Continuous casting eliminate the primary mills and
produce much superior quality material with high surface finish. It saves about 20%
energy. Rolling Mill can be categorized as Hot Rolling and Cold Rolling operations.
Pollution from a Rolling Mills mainly includes mill scale, oily mill sludge, oil emulsion,
pickling acid sludge, emission from reheating furnaces, Noise etc.

9.1 Mill Scale
      contains approximately 70 % Fe content. Presently approximately 100 % of the
total generation is either recycled or sold. Hence little pressure is there to develop
further technological improvement for the utilization of mills scale. Rolling Mill sludge
which generally comes out of the secondary treatment from the effluent from mills
mainly contaminated with oils and inorganic particles. As the mill sludge are fines
bonded with grease and oil, its’ utilization is difficult and presently being dumped in most
of the units. Technology to utilize this in the annealing zone of sinter bed has been
developed by Burns Harbour, technology transfer in this aspect is solicited as oily mill
scale have a great potential for air pollution.

9.2 Thin Slab Casting
      The important thin slab flat rolling technologies developed in the world are
Compact Strip Production (energy savings 50% over conventional Hot Strip Mill) and In-
line Scrap Process (energy savings 40% over conventional HSM). This is being
installed in the new generation Rolling Mills wherever feasible.

10. Waste Utilisation
      In an Iron & Steel Plant, about 85 % of the wastes is slag from Blast Furnace and
Steel Melting Shop. Hence utilisation of slag is an area of concern. Cement Plants can
take Blast Furnace Slag as a input material in it’s blend. High capacity Steel Plants can
install captive cement plants for the utilization of BF Slag. This will also attract CDM
benefit.
     Technology option for the utilization of other ferruginous and non ferruginous
wastes includes various pelletisation and rotary hearth furnaces. Fastmet process is
one such example.

10.1 Fastmet Process
     Fastmet is a coal based DRI (Direct Reduced Iron) process developed by Kobe
Steel Ltd. and Midrex Technologies, Inc. Iron bearing materials viz. virgin iron ores and
waste oxides are thoroughly blended with a reductant like coal or waste carbon and
rapidly heated in a Rotary Hearth Furnace to produce 85-92% metallised DRI in 6-12
Present Practices – An Overview                                                 [1.3 / 16 ]


minutes. This DRI is directly charged to Electric Arc Furnace to produce hot metal. The
hot metal produced in this process is same as conventional hot metal produced through
Blast Furnace route. This process utilizes metal bearing wastes both ferrous and non-
ferrous. Integrated steel plants find it difficult to process this waste and achieve zero
waste concept. The waste which can be processed through this technology include
residue from iron oxide screening, bag-house dust, mill scale, ESP fines, radial settling
sludge. This process can also utilize stockpiled metal bearing fines from various mining
and processing operations. This is a cost effective, energy conservative and
environment friendly process for recycling of steel plant wastes. This process is one of
the Best Available Technologies – converting Waste to Gold.

11. Energy / Green House Gas Emissions Reduction And Pollution Control
      Steel industry is one of the highest consumers of energy. It is evident that even
slight improvement in energy consumption in the Iron and Steel sector would mean
considerable saving of money from national point of view. The last two decades have
witnessed an unprecedented increase in the prices of energy available for steel
industry. This has initiated a renewed impetus for introduction of energy efficient
process technology as further energy conservation measures. The major energy inputs
in a steel plant are through Coal (coking & non coking, both), Electricity, Petro- fuels
and Steam, etc.
     The Indian Steel plants accelerated their focus towards energy conservation since
the oil crisis in 1973. Various energy conservation measures have been adopted
progressively in the Indian Iron & Steel plants. With the expansion plan of Iron & Steel
Industry, more thrust for energy consumption / conservation is solicited.




                                  Fig: 13 FASTMET Process
Present Practices – An Overview                                                   [1.3 / 17 ]


     The industry has made significant reduction in energy consumption, pollution
control and resource conservation, over the decade. However, specific energy
consumption at Indian steel plants is still in the range of 6.2 – 8.2 G Cal/tcs compared
with the global average of 4.5 G Cal/tcs. Particulate emission (PM) rate matter varies
from 1.6 to 2.5 kg/ tcs and water consumption varies from 3.9 to 7.6 m3/tcs, at the
Indian steel plants, compared to the best achieved figures of 0.5 kg /tcs and 5- 10
m3/tcs, respectively. Improvement in energy conservation and pollution prevention &
control at the Indian steel plants can be achieved through adoption of more efficient and
cleaner technologies. Energy consumption can be brought down by adopting various
techniques like Coke Dry Quenching (CDQ), injection of coal dust / tar / natural gases,
Top Pressure Recovery Turbines, more efficient & modern BOF process with
continuous casting, strip casting etc. In addition to these, energy efficiency of the steel
industry can be improved through recovery of sensible heat from high temperature flue
gases, improved recovery of furnace gases, better sealing & insulation of ovens /
furnaces, elimination of reheating processes, computerized combustion & process
controls, etc. All these modifications / measures not only conserve energy but also
reduce the CO2 emission and can get benefit from Clean Development Mechanism
(CDM) under the Kyoto Protocol.
     Energy audit at all plants have become mandatory in Integrated Iron & Steel
Plants. The report of the expert committee on Integrated Energy Policy of planning
commission has recommended for creation of National Energy Fund to finance Energy
Research and development which inter alias include technology up-gradation as well as
energy conservation & GHG (Green House Gas) emission reduction.
      Reduction in water consumption and effluent discharges can be achieved by
intensifying localized and centralized recycling systems. Adoption of dry cleaning of fuel
/ flue gases in place of wet cleaning will not only reduced the water consumption &
effluent discharge but also increase the recyclability of the dusts/fines. For improving
the air quality, de-dusting systems for capturing and cleaning the fugitive emissions
generated from the various operations like Cast House De-dusting Systems at Blast
Furnace & dog house at BOF can be installed.
     As per the National Steel Policy, steel production in India will increase from the
present level of 45 million tons to 110 million tones by 2020. During expansion, major
thrust will be given for adoption of best available technologies for further reduction of
specific energy consumption and pollution control.

12. Conclusion
      Indian Steel Industry is poised for a massive transformation, credit goes to the
significant change in the Indian Economy. Steel is the backbone for infrastructure
Present Practices – An Overview                                                    [1.3 / 18 ]


building and engine for development. Simple calculation reveals that even to catch up
the world average per capita consumption of 170 kg of steel, India’s production falls
short by 132 MT annually (which is almost three times of the present annual out put).
      To achieve global competitiveness, major expansion/ modernization and new
installations of Indian Iron and Steel Industry is underway. This steel making process is
associated with severe environmental impacts, from mining through production process.
With increasing concern at global and local levels on environmental degradation,
existing regulatory measures are being tightened and new regulations are on the anvil.
Project proponents of the expanding steel industry, when contemplating new
installations or expanding/modernization of the existing facilities, must have to plan
environmental safe guards to meet the more stringent pollution norms. The proposed
technologies must envisage Quality improvement of prime raw materials, maximizing
utilization of inferior grade of raw materials, total recycling of other ferruginous and non
ferruginous wastes, maximum thrust of energy saving and reuse, reduced GHG gas
emission, complete control of secondary emission and low particulate and gaseous
emission from the stacks through superior air pollution control systems.
    THE ULTIMATE OBJECTIVE IS, EVERY TONNE OF STEEL PRODUCED MUST
AIM AT IMPROVING THE QUALITY OF LIFE FOR EVERY ONE, NOW AND FOR
FUTURE GENERATIONS. IN ONE WORD SUSTAINABLE.

13. Acknowledgement
     The author acknowledges with thanks to the management of Steel Authority of
India for the valuable support that have been provided for publishing this paper.

14. REFERENCES
    1. Agrawal R.K. and B.M.K. Bajpai (1999), “Solid Waste Recycling,
       Reconditioning and Reuse”, in Proc. of REWAS 99 Global Symposium on
       Recycling Waste Treatment and Clean Technology, eds. I Gaballah, J Hager
       and B.Solozabal, Vol 2, San Sabestian, Spain, pp. 1638-1646.
    2. AISI, 2001. American Iron and Steel Institute, Steel Industry Technology
       Roadmap, AISI Report
    3. Ameling D (2000), “ New Developments in Integrated Steel Making in
       Europe”, MPT International, December-2000, 6, 36-42
    4. Balajee S R, P E Callaway, L M Jr Kelman and L J Lohmen (1995), “
       Production and BOF recycling of waste oxide briquettes containing steel
       making sludges, grit and scale at Inland Steel”, Iron and Steel Maker, 22, 8,
       51-55.
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     5.    Ban B C and B M Lim (1994), “ EAF-Dust Treatment by DC-Arc Furnace with
           Hollow Electrode and New Concept of Dust Recycling ”, SEAISI Quarterly,
           23, 1, 54-66
     6.    Cartwright D and J Clayton (2000), “Recycling oily mill scale and dust by
           injection into the EAF”, Steel Times International, 24, 2, 42-43.
     7.    Degel R and O Metermann (2000), “Redsmelt, An Environmentally Friendly
           Iron Making Process”, Steel Times International, 24, 2, pp. 30-33.
     8.    Fruehan. R J (1998), “Future Iron Making in North America”, in Proc of
           ICST/Iron Making Conference, ISS, Toronto Canada, pp. 59-67
     9.    Griscom F, J T Kopfle and M Landow (1999a), “ Don’t waste Waste-it could
           mean Profit”, Steel Times Inernational, 23, 1, 72-74
     10.   Griscom F, J T Kopfle and M Landow (1999b), “Fastmet-your Waste to Profit”,
           Steel World, 4, 2, 20-24.
     11.   Heinz J, Lehmkuhler and G Rath (1999), “Red Smelt: A Virgin Iron Making
           Process for Production of Low Residual Steel in Mini Mills”, Steel Times
           International, 43, 1, 56-61.
     12.   Hoffman G E (2000), “Waste Recycling with FASTMET”, Direct from Midrex,
           4th Quarter, in house publication, 15-17.
     13.   Holmes AT and D Greenwalt (1997), “Saldanha Steel Project – the Zero
           Emission Philosophy”, in Proc Iron Making Conference, Chicago, U.S.,
           pp.451-457
     14.   Kinzel J, O Pammer, W Gebert, W Trimmell and H Zellner (1997),
           “Successful Application of the Top Layer Sintering Process for Recycling of
           Ferrous Residuals Contaminated with Organic Substances”, in Proc.Iron
           Making Conference, Chicago U.S.,pp 377-383.
     15.   Landlow M P, J F, Torok, T P Barrett, J F Crum and J Nelesen (1998), “ An
           Overview of Steel Mill Waste Oxide Recycling by Cold Bonded Roll
           Briquetting”, in Proc ICSTI/Iron Making Conference, Toronto, Canada pp.
           1237-1242.
     16.   Ministry of Environment and Forests, Govt. of India, Notification dated the 6th
           January 2000 of Hazardous Wastes (Management and Handling)
           Amendment Rules 2000.
     17.   Vancini F (2000), “Strategic Waste Prevention”, OECD Reference Manual,
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           BF in Pohang Works”, SEAISI Quarterly, 28, 1, pp 27-29.
Present Practices – An Overview                                                     [1.4 / 1 ]


                THE WASTE MANAGEMENT AND INTEGRATED
                     UTILIZATION IN BAOSTEEL GROUP
                                    Ming Kang, Bin Liu
                              Baosteel Group, Shanghai,China
                              Email:tongjiliubin@yahoo.com.cn


      Abstract: On the basis of sustainable development, environmental protection and
ecological equilibrium are considered on the top of the list in Baosteel Group. The
integrated utilization strategy is carried out to industrialize the wastes or biproducts of
steel production such as slag, ash, water, gas, oil. The waste management in Baosteel
Group has formed three levels: The first level is to treat the waste as raw material of
related industry on the base of avoiding secondary pollution, which ensures regular
operation of steel making and avert the stack of wastes. The second level is to build up
series of integrated utilization programs, form the industry system technologies and
products system of waste management. The third level is to develop technology-
focused competitive products based on deep processing of wastes and by-products.
     Key Words: waste management, integrated utilization, sustainable development,
recycling economy

1.   Introduction
     The harmonious development of resource, environment, energy and population is
a key social problem in China even in the whole world. Environmental protection and
ecological equilibrium are considered on the top of the list in Baosteel Group on the
basis of sustainable development. In the implementation of the strategy as “quality steel
production”, it is also put forward as a integrated utilization strategy that carry out the
environmental protection policies, industrialize the wastes or biproducts of steel
production such as slag, ash, water, gas, oil.
     It has been making great progress in the management of waste in Baosteel Group
during 10 years of unremitting efforts. The integrated utilization ratio of the waste is
close to 100%. The integrated utilization of slag, ash, mud and oil is developping toward
the specialization and industrialization.

2.   Waste management is a path to the Recycling Economy
     Recycling economy is a new type of practical model to promote the sustainable
development in the current international society. It emphasizes the greatest efficiency in
the utilization of resources and also in the protection of the environment. Recycling
economy is different from the linear developing form of traditional large-scale industry, it
Present Practices – An Overview                                                       [1.4 / 2 ]


follows the "3R" principal of reducing, recycling and reusing, which makes the economic
activity as a close cycling system of "resource – producing – consuming – reclaimed
resource" and achieves a "win-win" result of the economy, enviroment and the society.
Therefore, the nature of the recycling economy is ecological economy, the core is the
integrated utilization of resources. The integrated utilization is the key part of the
recycling economy and it is also a path to the recycling economy and sustainable
development.
     Baosteel as a example of metallurgy industry in China, attaches great importance
to environmental protection and integrated utilization of resources. We recycles wastes
through internal and external ways, minimizes waste discharge to achieve the "zero
release" for years, We make it true that the “so-called waste” is very the “resources in
the wrong location”.

3.   The discharge and management of wastes in Baosteel
     Discharge Of The Waste
     It is produced more than 20 million tons of steel annually in Baosteel. With the
expanding and extending of the scale, the wastes hsve increased in both varieties and
volume, which reaches more than 10 million tons a year. According to the
characteristics of metallurgical waste, the industrial waste in Baosteel is divided into two
categories: ferrous wastes and non-ferrous wastes. The ferrous wastes include iron in
the metallurgical slag, oxide iron skin of rolling steel, gray iron dust, etc; non-ferrous
wastes are mainly fly ash, quenched blast furnace slag, dry blast furnace slag,
Bessemer steel slag, electric furnace slag, iron containing dust, waste refractory
materials, and other industry waste. As to statistics, in 2006 Baosteel discharged
industrial wastes with the amount of 11,667 thousand tons, including the slag, steel
slag, iron containing dust, iron oxide scales, waste acid, fly ash and other industrial
waste. Especially, the utilization ratio of such wastes as blast furnace slag, steel slag, fly
ash reached nearly 100 percent, more than 80 percent of the wastes was utilized by
various ways of utilization.
     The integrated utilization of the main wastes in Baosteel
     a) Development and Utilization of Slag Fine Powder
     As is the largest amount of metallurgical slag resources, blast furnace slag was
mainly sold to the cement company in before. It is used as high-performanced concrete
admixture as slag fine powder based on scientific research as guide. We have also
learnt advanced experiences from foreign countries and through many years of
scientific development. Specialized company was established to produce slag fine
powder and the company has participated in the formulation of national standards “the
granulated blast furnace slag powder used in cement and concrete ” (GB/T18046-
Present Practices – An Overview                                                    [1.4 / 3 ]


2000), which plays a guiding role on the development of the blast furnace slag powder
in China. At present, we have set up two grinding lines which produces 1 million tons of
slag fine powder each, the production has been widely used in many projects such as
bridges, Shanghai Grand Theatre, the Maglev project, and overhead roads. Blast
furnace slag fine powder promotes the utilization of wastes, not only greatly ease the
pressure of scarce resources, reduce the cost of concrete project, but also significantly
improved the performance of concrete in working ability, strength, durability and other
properties.
     b) Development and Utilization of Dry Slag
     To enhance the application value of the dry slag, the dry slag products have been
widely used in concrete roads, floors and blocks, three slag roadbed material, cement
admixture, new fossil cotton products and so on after many years of experimental
research and market development. Dry slag has many advantages such as stable
performance, small density, high strength and high temperature endurance, which can
be used as concrete aggregate.
     c. Development and Utilization of Steel Slag
     As a large kind of waste, steel slag has a great amount and many varieties. We
has made great progress in the use of recycling the steel slag in the plant. It is recycled
about 170,000 tons of steel slag stablely per year. We also make the utilization from
general back filling to apply to the cement production, road embankment material,
concrete projects and soft ground handling. Balance has been made between Emission
and utilization. The sesearch of steel slag has made great progress in the application of
composite admixture, dry-mix mortar and so on. Compared with the traditional
techonology on piles and bottom, the application of steel slag works as a low cost and
high allowable bearing pressure. The resistance to wear of the floor material using steel
slag is higher than that of ordinary aggregate concrete. The utilization of steel slag is
developed from simple working to the profound processing of resource utilization and
product orientation.
     d) Development and Utilization of Fly Ash
     The comprehensive utilization of fly ash in Baosteel Group has come through more
than 20 years by continuous research and productive practice. On the base of
breakthrough in high-capacity utilization and multi-channel exploration, fly ash has been
developed into several varieties as dry ash, wet ash, wetness adjusting ash, grinded
asd, compound ash and so on. These products are widely used in project backfilling,
road engineering, concrete or mortar projects, wall materials and insulating materials
especially that the grinded ash and compound ash has become the essential
components of the pump concrete because of its excellent flow ability and low hydration
heat. By 2003, we have made use of more than 600 million tons of fly ash, the utilization
Present Practices – An Overview                                                      [1.4 / 4 ]


ratio has been 100% for 13 years in series. The integrated utilization of fly ash is
gradually on the way of resources recycling.
     e) Development and Utilization of Waste Oil
     It generates thousands of tons of various waste oil every year in Baosteel Group.
In order to avoid environmental pollution and enhance the value of the use of waste oil,
we introduced waste oil processing equipments from the United States and set up 700-
ton recovery line of waste oil. The quality of the reproduct reaches the standard of the
clean oil. At the same time, we have made much research to develop numerous
technology and patents.
     f) Development and Utilization of Iron-Containing Dust
     Iron-containing dust is a waste of the most varieties and with the most
components. It includes: the mud from blast furnace gas, the converter mud, dedusting
ash of converter, electrical furnace, the mud of cold-roll or hot-roll, graphite mud in pipes
and so on. At present, the low zinc mud (such as the mud from blast furnace gas, the
converter mud ) is used for recycling. Other dust is simply disposed and then sold as
raw materials for cement plants and steel plants. .
      g) Development and Utilization of Waste Refractories
      It generates about 50,000 tons of refractories every year in Baosteel Group mainly
including: magnesia-carbon brick, magnesia-chrome brick, converter ladle brick and
others. There are seven major categories and dozens of varieties. In recent years, We
has increased the comprehensive utilization of waste refractories through scientific
research and market development. Some waste refractories are processed into
particles to mix with homogeneous new refractories products. We successfully
developed the technology as "the technology of making magnesia-carbon brick into
renewable raw materials", "the recycling technology of quartz sand". Thses technologies
are applied into the production. However, the utilization level of waste refractories in the
Baosteel is still relatively low in general.
      h) Development and Utilization of Desulfogypsum
      Baosteel, as a giant steel enterprise, has a relatively low emission of SO2 per ton
of steel. But, the total amount of emission reaches 35,000 to 40,000 tons / year, in
which the SO2 emission of self-owned power plant accounts for 80 percent. To reduce
pollution on the environment, Baosteel has been carrying out flue gas desulfurization of
the power plant and also the sintering system. Desulfurization devices have been put
into use in the power plant. We also set up a production line for wall plaster to suit the
market of surrounding aeras, which is prepared for deep processing and utilizatin of
desulfogypsum.
Present Practices – An Overview                                                        [1.4 / 5 ]


4.    Conclusion and Expectation
      Generally speaking, the waste management in Baosteel Group has formed three
levels: The first level is to treat the waste as raw material of related industry on the base
of avoiding secondary pollution, which ensures regular operation of steel making and
avert the stack of wastes. The second level is to build up series of integrated utilization
programs, form the industry system technologies and products system of waste
management. The third level is to develop technology-focused competitive products
based on deep processing of wastes and by-products. All that we do for waste
management is to insure clean production, helps to decrease pollution and increase the
ratio of utilization, which simultaneously brings in a new point for the economic growth
for the enterprise itself.
     It is certain that there are a lot to do in the aspect of integrated utilization according
to the demand of recycling economy. It is essemtial to strengthen international
exchange and cooperation. We can exchange successful application as well as
practical experience through communication. Let’s make great effort to make the waste
management a prospective career.
Waste in Mining, Iron & steel Industry                                             [2.1 / 1 ]


                     USE OF SUB-GRADE ORE A CASE STUDY

                                  Shri N.K. Mayson, ED (Mines)
                                                 &
                                    A. Mukerji, DGM (Tech.)
                                       Mines Organisation
                                         Bhilai Steel Plant

                                           Synopsis

      The global increase in demand for steel has caused a corresponding increase in
steel demand in India. To cope up with the demand players in both the Private and
Public Sectors are planning to increase steel production both through brown field and
green field expansion. Addition of new capacities of more than 100 Mtpa are proposed
in the next few years requiring an additional 160 Mtpa iron ore.
     At this rate a 20 to 25 year balance life of Indian Iron Ore beyond 2020 surely is a
major concern for the steel industry. The steady depletion of high grade, lump yielding
ore reserves, accumulation of large quantities of sub grade fines and tailings are
compounding the problem further.
     The need of the hour is to meet the challenge head on and devise technology to
beneficiate and agglomerate the tailings and sub grade fines. Bhilai Steel Plant has
already initiated proactive steps to utilize more than 11.5 Mt of tailings and 12 Mt of low
grade generated fines through suitable beneficiation and Pelletisation.

1.    Complete Paper
      Steel Industry in India is on an upswing because of the strong global and domestic
demand. India's rapid economic growth and soaring demand by sectors like
infrastructure, real estate and automobiles, at home and abroad, has put Indian steel
industry on the global map. According to the latest report by International Iron and Steel
Institute (IISI), India is the seventh largest steel producer in the world.
      The announcement of the 'National Steel Policy' in 2005 set’s out the
Government's vision for future growth of the sector. The policy largely aims to develop a
modern and efficient steel industry of world standards, catering to the diversified steel
demands. It focuses on achieving global competitiveness not only in terms of cost,
quality and product-mix, but also in terms of global benchmarks of efficiency and
productivity. It seeks to enhance indigenous production of steel to 200 million tonnes
(mT) per annum by 2019-20 from the 2004-05 level of 38.1 mT. This implies a
compounded annual growth of 11.5 percent per annum.
Waste in Mining, Iron & steel Industry                                             [2.1 / 2 ]


     India is the 4th largest producer of iron ore, producing around 154 million tonnes
annually, which is nearly 12% of the global output. India’s proven iron ore reserve at
25.2 billion tonnes is 7% of the world total at around 370 billion tonnes (of which high
grade >65 % Fe hematite is about 14 %).
    India's largest iron ore deposits are located in Jharkhand-Orissa belt, which
accounts for 44% of the total reserves, followed by Karnataka-Goa (32%) and
Chhattisgarh – Maharashtra (16%).
     Of the many problems that beset the steel industry, one is that India is deficient in
raw materials required by the steel industry. Iron ore deposits are finite and there are
problems in mining sufficient amounts of it.
     This problem can be tackled by optimum processing of raw materials, search and
use of low grade ores, beneficiation and sintering/pelletisation of iron ore etc.
    The National Mineral Policy, 1993 has outlined certain key objectives in the area of
mineral conservation and use like

      •     As minerals are exhaustible and non-renewable resources, their exploitation
            has to be done keeping in view not only the present but the long term needs.
      •     The best use of available mineral resources shall be ensured by adopting,
            during mining operation, effective measures for conservation and
            beneficiation, recovery of associated minerals and later by efficient
            processing of minerals.
      •     Conservation of minerals shall be construed not in the restrictive sense of
            abstinence from consumption or preservation for future use, but as a positive
            concept leading to augmentation of resource base through improvement in
            mining methods, beneficiation and utilisation of low grade ore and rejects,
            recovery of associated minerals, reduction in the requirements of minerals per
            unit of material output, etc.
      •     Utilisation of low grade minerals, mineral wastes and rejects shall also be
            encouraged through appropriate incentives.

       Bhilai Steel Plant, an integrated ore based steel works, was commissioned in 1959
with production capacity of 1.0 mT of steel. In successive phases, capacity was
enhanced to 2.5 and 4.0 mT in the year 1962 and 1984 respectively. Figure depicts
facilities available with Bhilai Steel Plant for 4.0 mt production. As of now this is the
largest steel plant in India with present capacity utilisation more than 100%.
Waste in Mining, Iron & steel Industry                                                   [2.1 / 3 ]


     Bhilai’s share in the 26 mT hot metal production earmarked for SAIL in 2009 -10 is
7.5 mT. The iron ore requirement in 2009 -10, vis-à-vis its current requirement is
tabulated below
                                         Iron Ore Requirement of BSP
  YEAR                                                07-08     08-09     12-13       17-18
  Hot Metal                                             5700      5800      7500         7500
  Sinter Production                                     7100      7100      9700         9700
  Skip Sinter                                           5652      5652      8245         8245
  Pellet                                                                     900          900
  Net Lumps Required                                    4768      4847      3323         3323

  Net Fines required                                    5176      4952      7813         7813

  Mines Potential                Lumps                  4196      4465      4032         3324
                                              Fines     4932      4604      6156         8399
  Surplus / Shortfall            Lumps                  -505      -382       709              1
                                              Fines     2630      1641     -1656          586
  % SINTER                                               58.0      57.6      67.5         67.5
  %LUMPS                                                 42.0      42.4      25.2         25.2
  %PELLET                                                                     7.4          7.4
     Note: For 2007-08 & 2008-09 short fall in the requirement of fines will be met from old fine
stocks.

     The iron mines at Dalli-Rajhara have been in production since 1958 and have so
far produced more than 207 mT of iron ore. With nearly 50 years of mining the ore
reserves have started dwindling giving rise to numerous constraints in mining thereby
creating a shortage of iron ore to meet the future requirement of the steel plant. The
current reserve position is tabulated below

1.1 Constraints in Mining
    •   Depletion of Ore Reserves at Iron Ore Complex
            •   Exhaustion of Ore reserves of Dalli Manual. Jharandalli & Mahamaya
                Mines by 2009-10, 2010-11 & 2011-12 respectively.
            •   Dalli Mech. Mine will be exhausted by 2014-15
      •     Working at lower horizons in Rajhara Mech. Mine below ground water table.
            Pit likely to go 130 m below water table.
      •     Increase of Silica & reduction of Lump yield with depth as we are nearing the
            BHQ basement
Waste in Mining, Iron & steel Industry                                                      [2.1 / 4 ]


                               Mineral Reserves as on 01.04.2007
       Mines                             Reserve (in MT)    Fe %      SiO2 %     Al2O3 %
       Rajhara Mech Mine                            20.67     67.31       1.76       0.84
       Dalli Mech. Mine                             32.87     64.09       4.38       2.26
       Jharandalli Mine                              9.97     63.44       4.36       1.90
       Dalli Manual Mine                             4.05     62.33       4.71       2.61
       Mahamaya Mine                                 4.32     62.00       5.00       2.90
       Dulki                                         7.66     63.67       3.60       2.76
       Total                                        79.54     64.88       3.48       1.83



1.2 Bhilai Steel Plant’s initiatives to use Sub-grade ores
    In order to supplement supply of iron ore along with a view to gainfully utilize the
accumulated slime (waste) & generated fines and facilitate environment management,
BSP is in the process of installing following two model projects.

      •     Reclamation and up gradation / beneficiation of low grade generated fines
            into sinter grade fines.
      •     Installation of Slime Beneficiation Plant along with down stream Pellet Plant
            for utilization of the tailings.

1.3 Beneficiation of Generated Fines
     12 million tonnes low grade fines (-8 mm) have accumulated at Jharandalli,
Mahamaya and Dalli Mines which have been termed as “Generated Fines”. These low
grade fines are having about 57-58% Fe content and contain 12-14% +10 mm fraction.
     It is proposed to reclaim / utilize these Generated Fines dumps by processing
through the existing Dalli Crushing, Screening & Washing Plant with certain
modifications.

2.    Benefits
      •   Gain-full utilization of low grade fines for iron making after beneficiation. The
          yield of beneficiated fines shall be about 60 – 65 % having +63 % Fe.
      •     Reductions in the dumping load at mines to an appreciable extent & reduce
            the influx of fine grained washouts which cause land degradation.
      •     The slime generated from beneficiation process can be further utilized as
            input to the beneficiation pellet plant being installed at mines.
Waste in Mining, Iron & steel Industry                                                 [2.1 / 5 ]


      •      In future all the regular generation of low grade fines shall be directly diverted
             to the proposed unit instead of dumping.

2.1 Slime beneficiation & down stream Pellet Plant
      Dalli Mechanized Mine has crushing, screening and washing facilities which
generates slimes beside washed lump and fines. The slimes are accumulated in a
tailing pond where solids settle down and clarified water over flows through weirs to
down stream water bodies. The pond is now almost full with 11.7 Mt slimes with an
additional generation of 0.78 Mtpa from day to day washing activities. The average Fe
content of the slimes is about 49% with size below 100 mesh.

      •      The proposed installation includes a slime beneficiation plant which will
             produce ore concentrate of 64% Fe grade with approximately 50% yield
             (Annex.-I).
      •     This concentrate will be the feed material for the Pellet Plant which would
            employ Grate Kiln – cooler process of pellet making (Annex. – II). Pulverized
            coal will be used as fuel for kiln firing.
      The pellet thus produced will be used in blast furnaces. The quality of BF grade
pellets is envisaged to be as follows:-
      Fe content                 :       63.50 (Min)
      Size                       :       9 -16 mm
      CCS                        :       250 Kg/p (Min)
      Reducibility               :       70% (Min)
      Swelling index             :       18 (Max)

2.2 Benefits
    •   Disposal of current slurry generation from the existing washing facilities and
        also gradually reclaim slimes from Hitkasa tailing pond.
      •      Gainful utilization of waste material (slime) for iron making in the form of
             pellets.
      •      Pellets will directly replace lump ore with additional advantage of improved
             productivity and reduced coke rate at Blast Furnaces.
      •      Recycling of huge quantity of water which is otherwise going as waste at
             present.
      •      Waste disposal load after ore processing/washing shall further reduce by
             about 50% - better waste management.
Waste in Mining, Iron & steel Industry                                             [2.1 / 6 ]


3.    Conclusion
      Such initiatives will not only meet the Objectives of the National Mineral Policy but
also establish the techno-economic feasibility of use of tailing and other sub-grade ore
for iron making thereby opening avenues for installation of similar units in India attached
to iron ore processing/washing plants. Beneficiation and use of such type of low grade
(Fe) hematite slime lying unused at various mining units will lead to benefits like -

      •     Sustainable and gainful utilisation of mineral resources
      •     Recovery of economic value from wastes
      •     Better solid waste management
      •     Creation of space for tailings generated in the future
      •     Reduction of pressure on primary mining
      •     Reduction in the dumping load at mines to an appreciable extent

     There are possibilities that the rejects of beneficiation plant may also be utilized
gainfully in the form of new products. This needs to be explored.
      Alternatively the rejects after slime beneficiation having very low Fe content can be
reclaimed and used for back filling of exhausted mine pits with subsequent afforestation.
Waste in Mining, Iron & steel Industry   [2.1 / 7 ]
Waste in Mining, Iron & steel Industry   [2.1 / 8 ]
Waste in Mining, Iron & steel Industry                                             [2.1 / 9 ]


About the Authors

      1.    N. K. Mayson Executive Director (Mines), Bhilai Steel Plant had joined
            Durgapur Steel Plant in 1971 after completing B.E. (Metallurgy) from Nagpur
            University. Worked in different capacities in rolling mills at Durgapur before
            assuming charge of ED (Mines) in Oct. 2006. Awarded the National
            Metallurgical Day Award. Has visited different countries like USA, UK, France
            Germany, Italy & Finland.
      2.    A. Mukerji Deputy General Manager (Tech.) Mines HQ, Bhilai Steel Plant had
            joined BSP in 1980 after completing M. Tech. (Applied Geology) from Saugar
            University. Qualified Lead Auditor for ISO 14001. Has visited Australia and
            China.
Waste in Mining, Iron & steel Industry                                             [2.2 / 1 ]


              BENEFICIATION OF LOW GRADE IRON ORE FINES
                            S. Madhavan & Saroj Jain, Essar Group

      Synopsis: Till date Indian Iron & Steel Industry had luxury of using High Grade
Ores for making Iron & Steel. With the increasing mining activity and exports of high
grade ores; high grade reserves are slowly & steadily getting depleted. Moreover,
existing high grade reserves are not readily being made available to new steel projects
due to a number of policy and procedural issues.

        With the ever increasing prices of iron ore in the international markets as well as
        non-availability of high grade reserves for new steel making capacities, it has
        become essential to look at low grade reserves as an alternative for sourcing Iron
        bearing material for the production of iron and steel.

        It has become economical and essential to go for Agglomeration Techniques like
        Sintering or Pellets making process to utilize the Iron Ore Fines after following
        suitable Beneficiation Techniques for the low grade ores containing high
        proportion of Alumina, Silica as well as slimes. It is a challenge for the
        Beneficiation plants to adopt a suitable process to achieve a proper liberation as
        well as keep the slime level under control.

        Essar has adopted a process to Beneficiate Low grade Iron Ore fines of about 58
        % Fe Content from Joda Sector to convert it to a suitable Pellet feed of about 64
        % Fe Content. The Beneficiation Plant will be set up at Dabuna, Joda Sector &
        the Beneficiated Concentrate will be transported by a long distance Slurry Pipe
        Line to a Pellet Plant being set up at Paradeep.

        The Paper Explains the process being adopted by Essar Steel Orissa Limited for
        the Beneficiation for up gradation from 58 % to 64 % Fe.

        It also explains the Eco Friendly & Economics of Slurry Transportation of Iron
        Ore Concentrate.


1.   Introduction
     India is a fast developing economy with GDP growth rate exceeding 8% during last
4 years. This growth rate is likely to be sustained for the next 10-15 years.
       Steel is the basic material for industrial development. Finished steel consumption
is likely to go to 74 Mtpa by 2012 and to a level of 120 Mtpa by 2018 from a level of 47
Waste in Mining, Iron & steel Industry                                               [2.2 / 2 ]


Mtpa in 2007. Production of 74 Mtpa finished steel would require about 125 Mtpa of Iron
Ore.
     India has reserves of about 12 Billion tonnes of iron ore. However, with the
increasing mining activity and exports of high grade ores; high grade reserves are
slowly & steadily getting depleted. Moreover, existing high grade reserves are not
readily being made available to new steel projects due to a number of policy and
procedural issues.
      Appropriate planning is required to have a consistent supply of Feed Material of
63.5+ Fe %. If we continue to consume High Quality Iron Ore Lumps, the resources in
the country will get depleted in a very short period. It is essential to utilize the fines to
full extent. The utilization of fines alone may not solve the resource problems. Hence
Beneficiation of Low grade fines is a must for sustaining steel industry in India.
      Essar Steel Orissa Limited is putting up 8 Million Ton Iron Ore Beneficiation Plant
at Dabuna in Joda Sector to utilize the Low Grade fines of about only 58% Fe to up
grade to 63.5+ Fe% using Beneficiation Techniques. Essar Steel has already put up a 8
Million Ton Beneficiation Plant at Kirandul, Bailadila, Chattisgarh to produce 67+Fe %
Direct Reduction grade high Quality material from Ore of 62-63% Fe %.

2.    Need For Beneficiation
      The Low Grade fines of 58% Fe% cannot be directly fed to Blast Furnace or DR
plants since it will be highly uneconomical due the presence of Gangue materials like
Silica & Alumina to the extent of 10%. This increases the Slag Volume abnormally &
demands high amount of Limestone & Dolomite as flux for maintaining basicity which
ultimately increases Coke consumption. Al2O3 also has a negative effect of increasing
reduction degradation Index & decreases productivity. Hence it is essential to reduce
the Alumina Content in the cold stage itself at a lower cost by proper Beneficiation
Techniques.

3.    Normal Beneficiation Techniques
      The following techniques are common for Mineral Beneficiation:

      •     Gravity Separation which uses principle of the difference in Specific Gravity
            between the valuable mineral & Gangue
      •     Magnetic Separation which uses the magnetic property of one material with
            Respect to other.
      •     Flotation which depends on surface characteristics of minerals. In this case
            certain chemicals will be added to modify the surface of one mineral which
            tends to float due tob surface tension & other material will sink.
Waste in Mining, Iron & steel Industry                                               [2.2 / 3 ]


      •     Electrostatic Separation which works on the principle of one material is
            conductive to electrical charge & other non conductive/less conductive.

      According to the nature of Ore, the quality of final product required, the value of the
ineral & the overall economics one technique or combination of techniques are being
followed by different mineral industries.

4.  Iron Ore Beneficiation
    Magnetite (Fe3O4) , Hematite (Fe2O3) & Geothite (Fe2O3.H2O) are common
minerals for Iron Ore.
    If the ore is contains Magnetite the process generally adopted is Low Intensity
Magnetic separation.
     The number of stages depends on the Nature of Ore , Feed Quality & Product
Quality. If ROM is a mixture of Magnetite, Hematite & Geothite the process followed is
Low intensity Magnetic Separation followed by Gravity Separation. If very high Quality is
needed then Flotation is followed after Magnetic as well as Gravity separation.
     In case of only Hematite & Geothite are present then Gravity separation followed
by High Intensity Magnetic Separation is normally the Beneficiation Route.

5.    Iron Ore Beneficiation In India
      Kudremukh Iron Ore Company Ltd.:
      Kudremukh Iron Ore Company (KIOCL) is the first company in India to install a 7.5
Million Ton per annum Iron ore Beneficiation Plant for the beneficiation of low grade
magnetite ore to High Quality concentrate for BF as well as DR feed material with the
consultancy help from MS Canadian Met Chem Inc., Canada as a 100% Export
Oriented Unit to supply concentrate to Iran. Due to political changes in Iran, the country
could not lift material in 1980 & the Concentrate was first exported to many other
countries since the same is a good feed material for sintering & Pellet.
      KIOCL, which started Iron Ore Beneficiation & commissioned the Beneficiation
plant way back in 1980 & the plant was beneficiating Low Grade Magnetite & Hematite
ore from 38% Fe content ROM to 67% Fe Concentrate. The process adapted was Low
Intensity Magnetic Separation followed by Spiral Gravity Separation. The plant added
Flotex density separators after Spirals followed by Mechanical Flotation & Column
Flotation Cells after second stage Low Intensity Magnetic Separation. The Beneficiated
concentrate was transported through a 67 KM long slurry pipeline from the Beneficiation
plant at Kudremukh to the Pellet plant at Mangalore for further process.
Waste in Mining, Iron & steel Industry                                               [2.2 / 4 ]


     The company’s Beneficiation Process stopped from 1-1-2006 after Hon. Supreme
Court verdict to stop Mining operations. That was the only Magnetite deposit in India
being mined.
      Essar Steel Ltd. (ESL)
      Essar Steel Limited has put up 8 Million ton Beneficiation Plant at Kirandul
(Bailadila Sector) to upgrade 62-63% Fe content Hematite Ore to produce 67% + Fe
content Direct Reduction Grade Concentrate. This is the only second plant in India for
Iron Ore Beneficiation & the fist plant in India for Hematite Beneficiation. The
Concentrate produced in the plant is pumped to the Pellet Plant at Vishakapatnam
through 260 Km long Slurry Pipeline. This is the longest distant pipeline in India passing
through three states in difficult terrain. The process adapted is Gravity separation by
Spirals & Magnetic Separation by High Gradient Magnetic Separation.
    For the liberation of the ore & for grinding the material suitable for Pipeline
Transportation, Ball Mills are installed.
     Challenges in Beneficiation for Orissa Ore
     The Low Grade Iron Ore Fines in the Orissa is having higher Alumina Content &
combined water. The alumina distribution & Geothite distribution is spreading in all Size
ranges. Hence it is the real challenge for Mineral Beneficiation with this type of material.
The common mineral Beneficiation methods are:

      •     Gravity Separation
      •     Magnetic Separation
    •     Flotation
    All the above methods requires de-slimed material as well as Liberation. In Mineral
Beneficiation, slime & liberation are two faces of the same coin.
     General Size Distribution of Orissa Ore
     The Coarser fraction of as received sample (+1mm ) fraction consists of Higher Fe
% than the average Fe % of the ore. But this fraction is not liberated. Only if this fraction
contains Fe % more than 63 + Fe % the same can be taken as Final Product. Only if
ROM Fe % is in the range of 60% & above the + 1mm fraction is having 63+ Fe %. In
case of 58% Fe in ROM the + 1 mm fraction is only 60 to 61 % Fe content which
requires liberation & further Beneficiation. The ultra fines of below 20 microns contains
only 45 % Fe content which can be taken out as waste slime before grinding. The
above constitutes 10% of ROM. Size distribution of typical are as follows for 58 % Fe in
ROM.
Waste in Mining, Iron & steel Industry                                          [2.2 / 5 ]


                Size in mm               % Retained    Fe %
              - 10 +6                       1.1       61.5
              - 6 +2                       37.5       60.5
             - 2+ 1                        18.2       60.0
              - 1 +0.5                     12.6       59.5
              -0.5 +0.21                    6.6       60.5
              -0.21+0.1                     5.7       58.0
             -0.1 +0.053                    2.7       57.0
             -0.053+0.02                    5.6       50.0
                -0.02                      10.0       45.0


      The minus 0.02 mm finest fraction which is only Slime with 45% Fe. The coarse
fractions needs grinding to liberate the material first at 1mm & below for Gravity
separation & below 150 microns for Magnetic Separation. The grinding should generate
least slime for better yield & to improve the efficiency of Beneficiation equipments.
     Process at Essar Steel Orissa
     The Process to be adopted in Essar Steel Orissa for Beneficiation is enclosed in
the form of flow sheet which shows the equipments and their sequence. The process
sequence is:
      Beneficiation Plant
      •   Screening at 10mm & Crushing the + 10 mm in close circuit with Screen.
      •   Classification of minus 10 mm fraction to separate slime at 100 microns
      •   De sliming Cyclones to reject minus 10 micron slime as overflow.
      •   Magnetic separation of De sliming cyclone Under flow.
      •   Screening of Classifier Coarse fraction at 1mm
      •   Primary Grinding of + 1mm Screen oversize in Ball Mill in close circuit with
          Screen.
      •   Gravity Separation of minus 1mm fraction.
      •   The concentrate of Gravity Separation is one part of Final Concentrate.
      •   Treat the Gravity Separation Tail in Magnetic separation along with de sliming
          cyclone under flow.
      •   Magnetic Concentrate is other final product.
      •   Magnetic tailings is final tailings.
      •   Regrinding of Concentrates in Secondary Ball Mill in close circuit with Hydro
          cyclones to produce final size at 99% passing 150 Microns & 70 to 75 %
          passing 45 Microns suitable for Pipe line transportation in Slurry form.
      •    Pumping of Concentrate through 253 km long Slurry line.
Waste in Mining, Iron & steel Industry                                                [2.2 / 6 ]


     Slurry Transportation
     Taking advantage of finer grinding our company decided to Transport the
concentrate in Slurry Form through 253 Km long Slurry Pipe line of 20” diameter. This is
a Eco Friendly way of transporting the concentrate. The advantages of this
transportation are:

      •     Transportation is Underground & no disturbance to people & traffic.
      •     No air pollution during Transportation.
      •     Conservation of Energy since no Fuel is required.
      •     The transported water is recovered in Pellet Plant after filtration & the same is
            used in Pellet Plant as make up water.
      •     The method is economical compared to other transportations.

      Pelletisation
      The Concentrate will be filtered at Paradeep & mixed with Bentonite & limestone to
produce pellets which is called as Green Pellets. The Green Pellets are heat hardened
in Indurating machine at 1320 Deg. C using Low Sulphur Oil as Fuel.
      The pellet produced is to be used in Blast Furnace as a feedstock.

6.    Conclusion
      •   It is possible to produce good quality Blast Furnace feed material Using Low
          Grade Iron Ore Fines using proper Beneficiation techniques. The Concentrate
          produced can be transported in Slurry form in an eco friendly & economical
          way. The agglomeration techniques of Pelletisation helps to produce material
          of correct size & strength material for Blast Furnace.
      •     Processing of low grade iron ore to high grade facilitates utilization of
            otherwise waste material. This low grade fine ore is presently not usable and
            is occupying space and causing environment hazards.
      •     Utilization of low grade is also in the larger National interest. By utilizing low
            grade ores, better quality material is being preserved for future generations.
Waste in Mining, Iron & steel Industry                                                                       [2.2 / 7 ]



                            RO

 Scree
             Roll
             crushe
                                                  +1
            Screw
                              Scree

                                                                        Intermediate
         Hydrocyclone                                                   thickener
                                        Hydrocyclone




                                                  Rougher                                 Magnetic
                                                  Spiral                                  separator
                                                            Cleaner
                                                            Spiral




                                                                                               Concentrate
                                                                                               thickener




                                                                                       Conc.
                                      Tailings
                                      thickener

                           Tails

                                      Flowsheet for iron ore beneficiation
Waste in Mining, Iron & steel Industry                                              [ 2.3 / 1 ]


                    WASTE MANAGEMENT EFFORTS IN
                IRON MAKING ZONE OF BHILAI STEEL PLANT
                                    Sajeev Varghese
                             Manager Blast Furnace (Operation)
                                     Bhilai Steel Plant


     The Blast Furnace (BF) is likely to continue as the main production process route
for hot metal in large integrated steel plants in the foreseeable future. The steel industry
wherein the quantum of raw materials, resource, energy utilization is high in magnitude
and which undergoes extensive processing, do certainly calls for greater management
and control efforts to minimize pollution, waste arising and optimize resource utilization.
Specific consumptions of natural resources and emissions / discharges to the
environment are mainly dependent upon the quality of raw materials, technologies, type
of pollution control equipments etc. Some of the waste management efforts of iron
making zone in BSP have been described below.

1.    Waste Heat Utilization From Stoves Of BF-6
      The flue gas from stoves is being used for drying of pulverized coal to bring down
the moisture level less than 1% in grinding system of Coal Dust Injection (CDI) for BF -
6&7. As the temperature of flue gas in stoves is about 180-200 degree centigrade, it is
further heated in hot gas generator with BF gas to attain the temperature required for
drying of coal. By using stove flue gas the size of HGG (hot gas generator) & its
peripheral are smaller in size and consumption of BF gas is less. Another distinct
advantage of using stove flue gas is less consumption of nitrogen gas, which is used for
inertization of grinding system.




                       Fig. 1. Pulverised Coal Dust Injection System
Waste in Mining, Iron & steel Industry                                              [ 2.3 / 2 ]




                        Fig. 2. Grinding System using stove off gas



2.   Reduction of SiO2 in iron ore fines
     Blast furnace route permits operations with high gangue materials at reduced
productivity. Carrying gangue through the high temperature steel making thermal cycle
has a huge environmental impact, compared to beneficiation of raw material at ambient
temperature before subjecting it to the iron and steel making temperatures.
       In Dalli mines of Bhilai Steel Plant, work has been carried out to decrease % SiO2
in the sinter fines from 4.4 to 3.9% to improve the functioning of the thickeners. It was
observed that the existing classifiers at crushing screening and washing plant can reject
fine silica particles through its overflow by operating with higher solid to water ratio.
Operating classifier at 20-25% pulp density increases the slime loss from existing 14%
to 19% and decreases silica content in iron ore fines by 0.5%. Increased slime loss was
also causing jamming of Radial settling tank and production loss. In order to reduce
silica content in iron ore fines & reduce slime loss, it is proposed to modify the Fluidized
Bed Classifier (FBC) system so that classifiers can be operated at higher pulp density
without thickener jamming.
    This modified system was able to recover iron fines concentrate with 63% Fe with
about 4% SiO2. FBC system was stopped due to failure of dewateriser screen. Now the
Waste in Mining, Iron & steel Industry                                                     [ 2.3 / 3 ]


damaged screen will be replaced by a slow speed spiral classifier (SSSC) unit to
recover the fine iron concentrate from the slime. It will thus ensure the slime loss to
remain at 14% level but improving the quality of sinter fines by decreasing 0.5% silica
content. As the faster settling iron particles would be recovered from SSSC unit, the
thickener jamming problem will be solved & clear process water will be recycled to the
Crushing Screening &Washing plant from the Radial Settling Tank pumping station
itself.
    Annual consumption of sinter in blast furnaces is 7.1 million tones for the year
2007-08. A reduction in SiO2 of .5% can reduce slag rate by 2kg/t of hot metal. Thus
annually we can save around 4000t of slag generation. The process flow diagram of
FBC and the proposed modification is given in Fig. 3. The civil work of the proposed
modification is almost complete & unit may start by Jan. 2008.

                                             -10 mm ore fines
     Slime –0.2 mm
     Fe:50%
     SiO2-14%                                      Duplex Spiral               -10 +0.2mm
                                                                               Sinter fines
                                                                                (avg.SiO2-4.4 %)

                         Fluidised Bed
                         Classifier (FBC)
                                                                          Slime beneficiation
                                                                          system
                              Slurry Pump
                                               Recovered fines: 50T/hr
                           Hydro cyclone       Fe: 63%
                                               SiO2 < 4%


                     Slow Speed classifier


                              Conveyor Belt                              Existing Fines
                                                                         Conv. Belt



3.   Use of LD slag in sinter & blast furnace
     The converter slag contains substantial amount of lime & iron. This slag is crushed
& screened at a separate place. The fines fractions are sent to sinter plant, which is
then used in sinter making to replace limestone. The lump fraction is sent to blast
furnace & is charged to the furnace as a replacement of limestone. This way we are
recovering the lime & Fe content of LD slag which otherwise goes as a waste.

4.  Covered Cast house troughs in BF-7
    It helps in substantial energy saving by preventing drop in overall hot metal
temperature during delivery to steel melting shops and also helps in controlling fugitive
emissions in cast house.
Waste in Mining, Iron & steel Industry                                            [ 2.3 / 4 ]


5.    Water cooling system
      A Closed loop demineralised water-cooling system has been installed at BF -7,
which is helping us in optimum usage of water. Apart from this the data generated by
the flow meter and temperature measurement devices are helping us to reduce the heat
losses of the furnace and making the furnace more energy efficient.

6.    Energy recovery from top gas
      BF-7 uses high top pressure for the improvement of productivity and the reduction
of coke rate. This high top pressure also provided an ideal opportunity for recovering
energy from the large volume of the pressurized gas generated. A project is in the
pipeline to tap this energy by means of an expansion turbine, which is installed after the
top gas-cleaning device. With this BF-7 can generate as much as 10 MW of electricity.
      These are some of the work done in the area of waste management & there is still
scope for improvement in reduction of waste & our ultimate target is to achieve zero
waste discharge. We all know that there is great impact on environment & efficiency of
the system for carrying high ash in coal & alumina in iron ore through the steel making
cycle. An additional 0.8 G calorie energy is consumed & 375 kg of carbon dioxide is
discharged for every ton of steel produced as a penalty for using high ash coal (say
17% ash) coal & high alumina iron ore fines (2-5% alumina) compared to an energy
efficient practice (say 10% ash coal & 1% alumina iron ore). In SAIL beneficiations of
raw materials particularly in high ash coals & high alumina iron ores should be taken up
on priority basis.
Waste in Mining, Iron & steel Industry                                            [ 2.4 / 1 ]


               SOLID WASTE MANAGEMENT IN COKE OVENS
                       OF BHILAI STEEL PLANT

                  S. Roy Chowdhury (Asst. Gen. Manager) Co. & Ccd
               Bhilai Steel Plant, Steel Authority Of India Ltd. Bhilai, (C.G.)



1.   Introduction
     Metallurgical coke making in by product recovery oven is one of the major source
of solid waste generation in an integrated steel plant where coke& coke oven gas are
the major source of energy. Right from the receipt, unloading handling, crushing
carbonization and subsequence coke handling dust & breeze is generated. The process
of coal charging of inside the oven, pushing & coke quenching operation generates lot
of waste into kind of hot air forms, dust, breeze, coke smaller freedom. Energy
requirement of this Steel Plant for heading purposes is mostly supplied by coke oven
gas, tar & pitch mixture.
     In the early nineties environmental regulation for coke oven emission was non-
existent, except for co emission (3Kg / ton of coke) & particulate emission (50Kg / m3).

1.   Waste Generation Sources

1.1 Coal preparation Plant
      In Bhilai steel plant, presently 15000 Ton / Day of coal of different grades &
different varieties are handle to cater the demand of production of coke 8000 Ton / Day
(Dry basis). Apart from unloading of coal, nearly 15000 Ton / Day coal is handling in
two area of coal preparation in coke oven BSP through stacker cum reclaimer & gantry
crane.
     In this area waste generated are mainly
     1. Coal dust generated during Coal crushing.
     2. Coal spillage from conveyer & chute areas.
     All the waste generated are being reused in situ.

1.2. Actions Taken For Reducing Waste Generation
     1. Dust suppression system is being reintroduced in Coal crushing area.
     2. Conveyor belt spillage reduction in Conveyor belt trough angle has been
          changed from – 25o to 35o.
Waste in Mining, Iron & steel Industry                                             [ 2.4 / 2 ]


     3.    Conveyor protective devices particularly, belt sway system are re
           Commissioned & chute jam limit switch has been installed for reduction of
           coal spillage.
     4.    All chute has been changed from mild steel to stainless steel for better flow
           ability.

2.   Reduction Of Dust Emission On Through Moisture Addition
     Factors like bulk density of Coal charge, energy requirement for Coke making and
flow ability of coal charge guide the extent of moisture in coal blend. Studies have
revealed that the bulk density of the change for the desired crushing level (80% through
3.0 mm) is more or less the same at a moisture level of 7.5 – 8.5%.
      At Bhilai Steel Plant water sprays have been installed in the Coal tippling station
and under each silo dozing the Coal for blend preparation. Sprinklers were also installed
in the open yard storing of Coal. Moisture addition was controlled automatically with the
help of solenoid valves & the blend moisture was maintained at 8 – 8.5% as against the
earlier figures of 6-6.5%. The above measures resulted in significant improvement in
working environment & operation in the Coal preparation Plant and Coke oven batteries.
On line coal moisture analyzer has been installed for better control & monitoring the
system.

3.   Coke Oven Batteries
     In Bhilai steel plant there are 10 coke oven batteries out of which Battery no
1,2,3,4,7,8 are 4.3 m high & are running, battery no. 5 & 6 (4.3m height) are under
rebuilding stage & coke oven battery no. 9 & 10 are 7m high & are also running &
present production of coke is 750 oven / day. (7900 ton B.F. Coke Dry Basis per day )
      In BSP coke oven batteries coal of quantity 16.5 ton (dry basis) are being charged
inside the oven (oven effective volume is 21.6 M3). The process of carbonization takes
place at a very high temperature 1200 – 1250oC in an air tight chambers. The coke
formation from coal takes about 17 to 19 hrs and after that coke is pushed from oven
through coke guide car into a quenching station where it is quenched with (phenolic
effluent came from coal chemical department for better environment). Quenched coke is
then stabilized in initially at wharf for steam removal & is sent through conveyers to coke
screening plant where particular size fraction (+25mm to –80mm) send to blast furnace
& other fraction send to sinter plant.(1,2,3)

4.   Sources Of Solid Waste Generation In Coke Oven Batteries
     The main processes which causes generation of waste in coke oven batteries
affects environment are listed below.
Waste in Mining, Iron & steel Industry                                             [ 2.4 / 3 ]


4.1 Charging of coal in coke oven
      Drawing of coal from coal tower to charging car bunker & as well as charging of
coal (16.5 ton / oven dry basis in 4.3m batteries, 30 ton / oven dry basis in 7m batteries)
into inside the oven, both these cases lot of coal spillage occurred due to lack of
automation in the system.

4.2 Coking Process
     Coal to coke conversion is the utmost important technology in coke oven &
maintenance of thermal regime & maintaining proper temperature in heating walls by
burning coke oven / blast furnace gas in heating flues is of utmost importance to
achieve proper carbonization, coke yield and coke quality. Improper heating leads to
green pushing, over coking, wastages to heating gas & may lead to sticker oven. Green
pushing (where coke mass temperature is not sufficient, i.e. coking not completed result
in evolution of thick black smoke to the atmosphere during pushing.

4.3 Oven Pushing
     After the carbonization cycle completed, in oven both side door needs open for
pushing out of coke from oven, as soon as quenching car is ready for receiving hot
coke. After pushing out of coke from oven, coke spillage occurred in front of both side of
oven. Improper mechanization of machine causes wastage of coke during pushing.
     Pushing of coke from oven to quenching car also produces lot of emission called
pushing emission. These emissions contain lot of ash, & coke dust, which increase
ambient SPM level.

4.4 Quenching process of Coke:
     In Bhilai Steel Plant hot coke is being quenched by phenol water effluent from coal
chemical department. During quenching lot of wastage are being generated in the form
of coke breeze at quenching pond & emission are produced during the quenching
process of coke in quenching station. It has high particulate matter contains coke dust &
ash particle.

5.   Coke Sorting & Coke Screening Plant
     In coke plant, coke spillage, coke dust & disintegrated coke have always been not
only a nuisance but also play an importance role for hindering the performance of plant.
      Important places where there particulate matter escapes out of the system are as
follows:
     1.    Transfer point of material at conveyors.
     2.    Coke culture &
     3.    Coke screen houses.
Waste in Mining, Iron & steel Industry                                                [ 2.4 / 4 ]


6.   Controlling Of Waste Generation In Coke Oven
     In order to control the generation of waste from coke oven batteries following steps
are needed.
      1. Reduce / generation of wastage eliminate.
      2. Effective management of wastage .
      3. Reuse of wastage.
      In batteries for reducing solid waste generations following actions are taken in
different areas.
     Areas                           Cause              Action
     1. Charging car Bunker          Spillage           1). All pocket opener for drawing
                                                        coal are in automode &
                                                        2).All Pocket opener are
                                                        interlocking with long travel of m/c.
     2. Charging car telescope                          Spillage at oven top P/S & C/S
                                                        telescope bunker charged at a
                                                        time & then middle bunker coal
                                                        changed & in middle bunker
                                                        sleeve with ring provided for
                                                        reducing spillage.
                                                        Timer introduced in middle
                                                        bunker pocket opener for full
                                                        charging of oven.
     Pusher car                      Spillage of coal   1). All pusher car
                                                        Leveling System in auto mode has
                                                        been installed.
                                                        2). All pusher car spillage chute tie
                                                        rod system provided for reduce of
                                                        coal spillage, earlier counter chain
                                                        system in flexible chute are there.
                                                        3). Leveler bar stand straightened
                                                        was done so that during leveling of
                                                        each. Oven, spillage coal came out
                                                        (nearly300kg) in coal spillage
                                                        bunker for reuse, which eliminates
                                                        coal spillage.
     Door Extractor machine          Dust emission      Battery no. 10 Door Extractor
                                     during pushing     machine (DE-3&4) hoods are
                                                        modified for dust emission
                                                        control.
                                     Spillage of coke   chain system has been provided
                                                        in cage of door extractor.

     In coke oven Battery NO-3 both coal charging cars, screw feeder charging system
has been installed for complete elimination of coal spillage at oven top level.
Waste in Mining, Iron & steel Industry                                          [ 2.4 / 5 ]


6.1 Combustion control of coke ovens
      Efficient combustion control system are being introduced in BSP coke oven Battery
– 3,9,10, 4 for proper combustion & heat control of coke oven. The system measures
end coke mass temperature with the help of infrared sensor located near. Door
extracter / Quenching tower. Correlation has been developed between temperature &
the actual coke mass temperature in the oven. This data is used to adjust the gas flow
rate to attain proper flue temperature in the heating walls. This saves not only heating
gas but eliminates green pushing, sticker formation & improves Coke quality also.

6.2 Modification in quenching process
     In coke oven Battery 9 & 10 quenching process has been modified in the following
areas.
     a). Quenching car & wagon modification.
     b). Quenching tower nozzle position modification.

     Quenching car operator cabin has been modified by changing window portion for
better visibility of operator and for better receiving of coke in quenching wagon.

6.3 Quenching wagon and Quenching nozzle modification
     All the holes for air circulation has been plugged & separate perforation has been
made in shutter gate of wagon, accumulates for few seconds & coke gets washed,
breeze are removed & more over due to high amount water in wagon for smaller time,
coke disintegration reduces drastically due to high thermal resistivity of coke due to
flood style quenching.
     Quenching tower nozzle angle has been changed from 900 to 1350 for smooth &
uniform quenching. Earlier water sprayed from nozzle couldn’t quenched the coke in
wagon receiving side & as water didn’t reach the spot. By changing the angle, problem
has been rectified. All the quenching route material has been changed from Mild Steel
to Stainless Steel for better life.
      In this way Quenching pond breeze generation has been reduces from 48 Dump
car to 40 Dump car in Battery 9 & 10 per month.

7.   Coke Sorting Plant
     All the transferring point of coke conveyor chute has been modified to Box type
chute from inclined chute so that direct impact of coke (which causes generation of coke
dust, coke breeze & nut coke) has been eliminated, diabase lining has been done in all
chutes.
Waste in Mining, Iron & steel Industry                                                [ 2.4 / 6 ]


      In screening area all 25mm grizzly 12 rolls has been provided for better screening
& in continues vibrating screen, double spring has been installed & angle of screen has
been changed from150to 221/20, for better screening. More over the convergent of
grizzly chute has been modified for effective utilization of grizzly rolls & as well as at the
end of grizzly roll, socket has been provided for eliminating coke breakages (which
causes coke disintegration.
     In these specific area by modifying CSP equipment BF grade coke generation has
been increased by 1%, and in Bf coke bunker coke fines has been decreased. More
over coke (-25mm) size fraction has been decrease from 3.3 T/Oven to 2.26 T/oven.
     All conveyers width has been increased from 1200mm to 1400mm & trough angle
has been changed from 250 to 350 & some leveler arrangement has been installed for
complete elimination of coke Spillage. Special type scrapper has been provided for
separating coke fines from conveyor (non carrying side).
      In Tripper care for coke feeding in Bf coke bunker limit switch has been installed
for complete elimination of break down & Spillage of coke.

7.1 Management of Waste
    In coke oven starting from coal to coke feeding, waste of different type are
managed differently.

7.2 Waste in Coal Plant
    All solid waste generated in coal plant has been reused in cycle by cleaning
manually

7.3 Waste In Coke Oven Battery
    Solid waste generated in coke oven Battery has been reused in two ways.
     Mechanized / manually mode used in battery area
     Manual mode in coke sorting area.
     Manual cleaning has been done for coal Spillage, & coal dust & reuse them in coal
plant.
     Mechanized mode like coke thrower used in coke pusher & JCB are being used for
coke Spillage occur during coke production, which is recycle with coke at stock yard.

7.4 Manual cleaning Process
     4 truck each having 6 Ton capacity regularly engaged for total territory cleaning
specially coal / coke dust / breeze, coke particle. Nearly 4x6x5 = 120 Ton coal dust are
being generated & reused in their system.
Waste in Mining, Iron & steel Industry                                                       [ 2.4 / 7 ]


                 Different size fraction of coke are handling in different areas.
 Fraction                   CSP-1                  CSP-2                 CSP-3
 +25 mm to –80 mm           BF 1 to 4              Bf 4,5/6              BF-7 & 6,5
 +20 mm to 25 mm            SP-3                   SP-3                  Sp-3
 -20 mm                     SP1                    SP-2                  SP-3
 Quenching pond breeze.     Soaking pit BBM        Soaking pit BBM       Soaking pit BBM


                            Sintering Plant I      Sintering Plant I     Sintering Plant I
 Coke dust                  K-0                    K-0                   K-0
 Coal dust                  CHP                    CHP                   CHP
 Coke particle              Coke Stock Yard-2      Coke Stock Yard-2     Coke Stock Yard-2



7.5 New screen provided in coke stockyard – 2
     In coke stock yard –2 two conveyor belts 24 C1 & 24C2 which fed coke to BFs & as
well as coke loading facility has been introduced with a new conveyor belt 24AC2 screen
has been introduced for separation coke smaller size –25 mm & +25 mm.

7.6 New coke screen at CHP –I
     New screen has been installed at CHP –I area for coke particulate separation of –
25 mm & +25 mm. This is for exclusively the coke fines generated from Blast furnace
coke bunker.
     As Blast furnace –7 coke screen size is +35mm so-35mm size coke generated
from Bf-7 is reused for screen & coke fines are sent to SP-3 & +25mm fraction of coke
is used in CSP-I for feeding to blast furnace.

8.   Conclusion
     Coke oven Batteries are considered to be one of the major contributors towards
waste generation & atmospheric pollution in the Steel industry. The coal preparation,
oven charging, pushing & quenching & coke screening operation causes lot of wastes in
kind of dust, coke particles, coal spillage, coke breeze, coke fines, that are considered
to be the harmful to the human system & this generation & their handling also
considered to be prime important for smooth production of coke oven. Due to large
number of emission sources, their transient nature, long life of coke oven batteries etc.
Control of emission from coke oven is a difficult task.
Waste in Mining, Iron & steel Industry                                        [ 2.4 / 8 ]


     Over the years a large number of different type control measures in the coke oven
have been introduced by the SAIL BSP in the different areas of coke oven Batteries to
improve significant working environment in the operating batteries.

9.   Reference
     1. Bandopadhyay s.s et al 1992 Modification of coke oven doors with heat shield
         to reduce gas emission.
     2. nashan G (1987) Coke making international volume no. 1 1987.
     3. Mr. Ghosh. RDCIS in EFCI, 2002 Production of BF Coke in Cleaner
         Environment.
     4. Abhijit Misra, in EFCI, 2002 Coke plant at Tata steel a technologies model for
         environment construction.
Waste in Mining, Iron & steel Industry                                                                      [ 2.4 / 9 ]


                POST CARBONIZATION TREATMENT OF COKE PRESENT STATUS

                                            COKE FLOW DIAGRAM


     BATT-1      BATT-2           BATT-3      BATT-4          BATT-6       BATT-7    BATT-8          BATT-9




                          CSP-1                                    CSP-2                     CSP-3




         SY-1      BF-1           BF-2      BF-3       BF-4        BF-5       BF-6    BF-7           SY-2




                                                                                                      BSP




                            “ICS NORM OF COKE IN BHILAI STEEL PLANT”


          Coke Quality                      CSP-1                  CSP-2              CSP-3
                                           2006-07                2006-07            2006-07
         M10 (MAX)                            8.2                    8.2                8.0
          M40 (MIN)                          80.4                   80.4               80.4
         CSR (MIN)                           64.8                   64.8               64.8
           S (MAX)                           0.55                   0.55               0.55
          CRI (MIN)                          22.0                   22.0               22.0
       MOISTURE (MAX)                         4.0                    4.0                4.0
        +80 mm(MAX)                          8.5                     8.5                8.5
           -40 mm                            22.0                   22.0               22.0



                                                                                                      BSP
Waste in Mining, Iron & steel Industry                                       [ 2.4 / 10 ]



                      POST CARBONIZATION TREATMENT OF COKE
                                         PRESENT STATUS

                                          COKE QUALITY
      COKE Quality              CSP-1                CSP-2      CSP-3
                               2006-07              2006-07    2006-07
          M10                    8.0                   7.9        8.0
          M40                    80.7                 80.9       80.5
          CSR                    65.4                 65.3       65.3
          CRI                    22.6                 22.7       22.7
       MOISTURE                   3.5                  3.6        3.8
        +80 mm                    8.6                  8.1        7.9
        -40 MM                     -                  17.0       21.8
       SULPHUR                   0.51                 0.51       0.51
       MEAN SIZE                 54.6                   -        54.0

                                                                            BSP



                   “EQUIPMENT USED IN POST CARBONIZATION PROCESS”

                              INSTALLED EQUIPMENT STATUS

      EQUIPMENT                  CSP-1               CSP-2          CSP-3
     80 MM GRIZZLY                 5                   5             10
      NO.OF ROLL
    80 MM CRUSHER                  √                      √           √
     25 MM GRIZZLY                 6                      6          12
      NO. OF ROLL
      CONTINUOUS               28.5 MM              28.5 MM     28.5 MM
       VIBRATION
      SCREEN SIZE
      IVS SCREEN                20 MM                20 MM          20 MM


                                                                            BSP
Waste in Mining, Iron & steel Industry                                        [ 2.4 / 11 ]




           POST CARBONIZATION TREATMENT OF COKE PRESENT STATUS

                               COKE QUENCHING PROCESS

       QUENCHING              BATTERY           BATTERY             BATTERY
         SYSTEM                   1-8               9                 10
     CONVENTIONAL
    TOP QUENCHING                  √                √                  √
       (STAGGER)
           SIDE
       QUENCHING                  ---               √                 ---

                                                                            BSP




                     POST CARBONIZATION TREATMENT OF COKE
                               PRESENT STATUS

                                   COKE SIZE IN 2006-07

                SIZE FRACTION                             AVERAGE %
                   +100 MM                                   2.1
                    +80 MM                                   10.2
                    +60 MM                                   19.4
                    +40 MM                                   40.1
                    +25 MM                                   19.8
                    + 10 MM                                  5.6
                    - 10 MM                                  2.9            BSP
Waste in Mining, Iron & steel Industry                                          [ 2.4 / 12 ]



                     POST CARBONIZATION TREATMENT OF COKE
                               PRESENT STATUS
                        SKIP COKE ANALYSIS 2006-07 (PERCENTAGE)

          SIZE                  CSP-1            CSP-2               CSP-3
        +100 MM                  NIL              NIL                 NIL
         +80 MM                   8.4             8.6                 7.4
         +60 MM                  25.5            25.6                 23.1
         +40 MM                  43.8            43.0                 45.9
         +25 MM                  21.2            21.0                 22.5
         +10 MM                   1.1             1.0                 1.1

                                                                             BSP


                        POST CARBONIZATION TREATMENT OF COKE
                                  PRESENT STATUS
                            POST CARBONIZATION PROCESS
         CSP-3                CSP-1           CSP-2                 CSP-3
      EQUIPMENT
       CHANGING
      FREQUENCY
     80MM GRIZZLY             6 MONTH          6 MONTH             6 MONTH
         ROLL
    80MM CRUSHER              6 MONTH          6 MONTH             6 MONTH
       SEGMENT
     25MM GRIZZLY             2 MONTH          2 MONTH             40 DAYS
         ROLL
      CVS SCREEN              3 MONTH          3 MONTH              3 MONTH
      IVS SCREEN              3 MONTH          3 MONTH              3 MONTH
    COKE MOISTURE                ---              ---             INSTALLED &
       ANALYZER                                                     WORKING
                                                                             BSP
Waste in Mining, Iron & steel Industry                        [ 2.4 / 13 ]




                      POST CARBONIZATION TREATMENT OF COKE
                                  FUTURE PLAN

                                         FUTURE PLAN
    BATTERY – 5

        1) SUBMERGED QUENCHING SYSTEM (TOP & BOTTOM).

        2) WHARF – 3 AUTOMATION DRAG PLOUGH SYSTEM.

        3) CSP-2 PLC BASED CONTROL SYSTEM

        4) A) DRYFOG SYSTEM FOR DUST SUPPRESSION

           B) WHARF BELT (HOSCH MAKE) SCRAPPER

        5) MOTORISED WHARF BELT CHANGING FACILITY             BSP




                       POST CARBONIZATION TREATMENT OF COKE
                                   FUTURE PLAN

                                         FUTURE PLAN
         BATTERY – 11

         1) COKE DRY QUENCHING

         2) WHARF AUTOMATION

         3) PLC

         4) DE SYSTEM



                                                              BSP
Waste in Mining, Iron & steel Industry                                     [ 2.4 / 14 ]




                      POST CARBONIZATION TREATMENT OF COKE
                                  FUTURE PLAN

                                         COKE QUALITY
    BATTERY – 5


    MOISTURE                                3.5%(MAX)
    VM                                      0.8
    M 10                                    8.0(MAX)
    M 40                                    81 (MAX)
    CSR                                     MORE THAN 63.5%




                                                                           BSP



                                    SIX SIGMA FILTER CONE


                                    25 factors received from I/O sheet


                                   12 factors filtered from c & E Metrix




                                    6 factors filtered from FMEA



                                              4 inputs for
                                                  DOE
Waste in Mining, Iron & steel Industry                        [ 2.4 / 15 ]




                         PHASE-4 – CONTROL
   RESULT
   BEFORE PROJECT               AFTER PROJECT
   MONTH          MOISTURE %    MONTH           MOISTURE %
   NOV’04         5.8           JAN’06          4.7
   DEC’04         5.6           FEB’06          4.8
   JAN’05         4.3           MARCH’06        4.9
   FEB’05         5.01          APRIL’06        4.6
   MARCH’05       4.81          MAY’06          4.5
   APRIL’05       5.06          JUN’06          3.9
   MAY’05         4.66          JULY’06         3.8
   JUN’05         5.29          AUG’06          3.8
   JUL’05         6.03          SEP’06          3.8
   AUG’05         5.32          OCT’06          3.7
   SEP’05         5.26          NOV’06          3.7
   OCT’05         5.24          DEC’06          3.7
   NOV’05         5.5           JAN’07          3.7
   DEC’05         5.58          FEB’07          3.7
                                MARCH’07        3.6
                                APRIL’07        3.6
                                MAY’07          3.7
                                JUN’07          3.8



                                                             BSP
Waste in Mining, Iron & steel Industry                                         [ 2.4 / 16 ]




                REDUCTION OF BF COKE SIZE (- 40MM)

                IN CSP-3 OF BATTERY – 9 & 10 CO & CCD




                            BHILAI STEEL PLANT, BHILAI


                                                                           BSP



 STATUS IN 2005-06                        -         22.3% (MONTHLY AVERAGE)
 TARGET                                   -         21.5% (MONTHLY AVERAGE)
 RESULTS (DEC.06 – MAY 07)                -                (MONTHLY AVERAGE)
 LOCATION                                 -         COKE SORTING PLANT –3
 METHODOLOGY APPLIED                      -         SIX SIGMA

 TIME OF COMPLETION                       -         SIX MONTHS
 OF PROJECT

 BENEFITS : -    1. IMPROVEMENT IN BF COKE YIELD.
                 2. IMPROVEMENT IN BF OPERATION PRACTICES.
                 3. IMPROVEMENT IN BF PRODUCTION.
                 4. LESS HANDLING OF –40MM COKE.
                 5. COKE SIZE IMPROVED.



                                                                           BSP
Waste in Mining, Iron & steel Industry                                             [ 2.4 / 17 ]




                      BEFORE PROJECT                        AFTER PROJECT
            MONTH                  40MM               MONTH                40MM
            Oct’ 05                23.5                Oct’06               22.5
            Nov’05                 21.8               Nov’06                22.3
            Dec’05                 21.8               Dec’06                21.3
             Jan’06                21.8                Jan,07               20.6
            Feb’06                 21.4                Feb’07               20.7
           March’06                23.2               March’07              20.7
            April,06               23.2               April’07              21.1
            May,06                 22.8               May’07                22.0
            June’06                22.8
            July’06                22.1
            Aug’06                 22.2
            Sept’06                22.2


                                                                                   BSP
           Table: Comparative productivity figures for different size ovens
         Parameters                Small   Large oven       Huckingen    Prosper   Kaiser
                                   oven    (Orghishima)                            Stuhl III
 Dimension (Usable),Height,m       4.50        7.65              7.85     7.10       7.63
                       Length, m   11.7        16.4              17.2     15.9       18.0
                       Width, m    0.450      0.435              0.550    0.590     0.610
                  3
Useful volume m                    22.1        52.2              70.0     62.3       78.9
Productivity, Coke/Oven, t         12.7        32.0              43.0     39.8       48.7
No. of ovens                       322         123               120      142        120
Total oven openings                2898        984               1080     1278      1080
Length of sealing faces, Km        10.5        5.1                6.0      6.2       5.5
No. of pushing/day                 430         171               128      138        115
Total of opening cycles/day        3870       1368               1152     1242      1035
Length of sealing faces to be      14.0        7.0                5.0      6.6       5.3
cleaned Km/day
(Capacity: Coke, 2Mt/year)
Waste in Mining, Iron & steel Industry                                              [2.5 / 1 ]


         EFFECTIVE BIOLOGICAL TREATMENT OF COKE OVEN
     BY PRODUCT PLANT’S EFFLUENT FOR REMOVAL OF AMMONIA,
         CYANIDE & PHENOL WITH A SPECIAL REFERENCE TO
                     ROURKELA STEEL PLANT

                           * Dr. B N Das, GM (Env. Management)
                  * B Vaidyanathan, AGM (Coal Chemicals Department)
                          * K K Manjhi, Sr. Mgr. (Env. Engg.Dept)
                        * Dr. S P Kalia, Dy. Mgr. (Env. Engg. Dept)
                            Rourkela Steel Plant, SAIL, Rourkela

1.    Introduction
      The Iron & Steel Industry in general is one of the major contributors of
environmental pollution due to the complex and diversified nature of raw materials and
by-products handled and various waste products, discharged into the surrounding eco-
system. Starting from mining of iron ores and fluxes and their beneficiation to coke
making, iron making, steel making and rolling, various solid, liquid and gaseous
pollutants are liberated which contribute to air, water, land and noise pollution which call
for proper treatment and disposal for better environmental management.
      One of the major pollution problem encountered in steel industry is treatment of
wastewater generated from various process. The waste water generated from Coke
Oven By Product Plant is the most polluted water arising from any Integrated Steel
Plant. This wastewater contains toxic chemicals like Phenol, Cyanide & Ammonia,
which are harmful to receiving water bodies when discharged, untreated.
      Rourkela Steel Plant is an integrated Iron & Steel Plant which was set up in the
year 1959 and modernised in early 90s to a production capacity of 1.9 MT of crude
steel. About 5000T of coal is carbonised daily to produce coke, which is an important
raw material for making hot metal along with iron ore. While making coke, lot of raw
gases are generated in Coke Ovens which will be cleaned and number of by products
like Tar, Benzol, Naphthalene, Carbolic acid, Pitch, Anthracene oil are separated in
Coke Oven By Product Plant commonly known as Coal Chemicals Department. The
cleaned coke oven gas is used as a main source of energy for various operations in the
steel plant.
      Lot of water is used in various operations in Coal Chemicals Department for
purification of coke oven gas and production of various byproducts. During the process,
wastewater is generated to the tune of 150 to 175 m3/hr. This wastewater is highly toxic
and contains high concentrations of Phenol, Cyanide & Ammonia.
Waste in Mining, Iron & steel Industry                                              [2.5 / 2 ]


      There are various methods to treat the wastewater arising from Coal Chemicals
area. The various processes can be categorised into two i.e concentration process and
oxidation process. In concentration process the pollutants are removed from the effluent
by concentration of pollutants into a small volume of waste that itself requires same
form of treatment of disposal. The concentration processes include adsorption of the
pollutants on activated carbon or ion exchange media, osmosis solvent extraction. In
oxidation process, the pollutants are oxidized to relatively harmless end products by
either chemical or bio-chemical means. Chemical oxidation includes, oxidation by
ozone, chlorine, electrolytic action. Biochemical oxidation methods include oxidation of
pollutants by using microorganisms. Biological oxidation is the most widely practiced
method and is generally followed by some other processes as a Polishing step. For
complex wastes generated in the carbonisation process, it is difficult to find a single
process that offers complete treatment. BOD (Biological Oxidation and Dephenolisation)
is the most common and preferred root through out the world because of its simplicity in
operation and easiness in maintenance. In all steel plants including SAIL plants, the
BOD plant was is being operated which was installed earlier and revamped recently.
There is certain variations in process and equipment in different steel plants but the
essential principle is the same.
     Principle of BOD plant: The pollutants present in the waste water are removed
due to oxidation/digestion by micro organisms. A common BOD plant consists of
various units and its flow chart of BOD plant is given in Annexure-1.
       The waste water arising from Coal Chemicals department generally consists of
various pollutants viz., tar, oil, phenol, cyanide & ammonia. The microorganisms are
highly sensitive to shock loads. To eliminate shock loads, equalisation tanks are
provided generally to make the influent, homogeneous. These equalisation tanks also
act as a place for settling tars and other suspended solids present in the influent. The
presence of oil in influent badly inhibits the growth of microorganisms. Oil is first
removed by means of dissolved air floatation (DAF) system before putting in for
biological oxidation. The wastewater, which is uniform in nature, is admitted into first
stage aeration where oxygen is supplied by means of mechanical aerators. The
required nutrients like phosphorous is supplied by addition of 5% phosphoric acids and
Nitrogen portion of nutrients are met through ammonia present in the wastewater. The
presence of Pseudomonas bacteria in aeration tank where sufficient oxygen is
maintained (>4 mg/lit) by aerators, help in multiplying their population by taking phenol
as food and come to an equilibrium as per food to mass ratio (F:M) of 0.4 so that no
nitrification can take place in the first stage aeration. After reduction of Phenol in first
stage, the liquor is admitted into a clarifier where the sludge is allowed to settle and the
supernent liquor is send to Trickling filer for removal of Cyanide.
Waste in Mining, Iron & steel Industry                                                [2.5 / 3 ]




        The liquor is sprayed on filter media and allowed to pass through it. During passing
through the filter media, Cyanide and thiocyanide are oxidised by the microorganisms
present on the surface of the filter media and form into a layer called slime layer. The
microorganisms will grow by taking Cyanide as food oxygen from the ambient air. The
microbial growth will increase thickness of the slime laver on the filter media till the inner
most layer of the microorganisms will die due to non availability of oxygen. This will lead
to slashing of the slime layer and the dead microorganisms will fall down along with
flowing water. The liquor is recycled to maintain sufficient hydraulic loading on Trickling
filter.
      After removal of Phenol, Cyanide & Thiocyanide, the liquor is treated in second
stage aeration, where Ammonia is removed. The ammonia is converted into nitrite by
Nitrosomonous microorganisms and nitrite is converted into nitrate by Nitrobacter
microorganisms. The nitrification reactions tend to make the medium highly acidic which
inhibit the growth of microorganisms. The growth of microorganisms is given in
Annexure-2.
                                     NITROSOMONOUS
                      2 NH4+ + 3O2             2 NO2- + 4H+ + 2H2O

                                         NITROBACTOR
                      2 NO2- + O2                  2 NO3-

                                         NITRIFIERS
                      NH4+ + 2O2                            NO3- + 2H+ + H2O
Waste in Mining, Iron & steel Industry                                             [2.5 / 4 ]


                                                   STATIONARY PHASE

                                       GROWTH CURVE OF MICRO ORGANISMS
                 3.5

                               3
     LOG (BACTERIAL DENSITY)




                 2.5

                               2

                 1.5

                               1

                 0.5

                               0
                                   1        1.75        4.25          5      7
                                                        TIME


      Alkali is dosed to maintain pH in the range of 7-8.0 and orthophosphoric acid as a
nutrient for better growth of microorganisms. The liquor is taken to second stage clarifier
where the mixed liquor suspended solids are allowed to settle down. The bottom
settled MLSS is recycled to second stage aeration tank to maintain optimum
concentration of bacteria in aeration tank. The supernent liquid is finally taken to clear
water sump and recycled back to Coke Ovens/Coal Chemical Department for reuse.
       Inherent problems with BOD Plant: Pre-treatment of tar & oil are essential
otherwise bio-organisms are destroyed by them. Inconsistent and high shock loads also
kill the microorganism and wash out occurs due to any problem in the plant operation.
Physio chemical condition like pH, flow rate, temperature, and retention time are very
critical to sensitive microorganism. The culture once destroyed is to be replenished by
fresh organism and they must be made acclimatized to the particular operating
conditions. The process also demands strict operational and technological discipline
otherwise washouts can occur frequently. This is also a slow kinetic process requiring
high residence time

2.    Bod Plant In Rourkela Steel Plant
      Biological Oxidation and Dephenolisation plant was set up to treat the waste water
arising from CCD in February, 1994 with an investment of Rs.8.32 Crores. Different
types of microorganisms in BOD plant treat the pollutants. The organic carbon present
Waste in Mining, Iron & steel Industry                                             [2.5 / 5 ]


in toxic substances viz., Phenol, Cyanide & Ammonia are bio chemically oxidised by
uni/multi cellular organisms like autotrophic bacteria, crustaceans by consuming part of
it to build their own cell tissues and part of it to produce energy for their survival and
producing CO2 and water as end products which are harmless to environment.
        The BOD plant has the following units for treatment of wastewater in stages;
     a) Equalisation tank
     b) Dissolved air floatation unit for removal of Tar & oil
     c) First stage aeration tank (AT#1) for removal of Phenol
     d) First stage clarifier
     e) Trickling filter for removal of Cyanide
     f) Second stage aeration tank (AT#2) for removal of Ammonia
     g) Second stage clarifier
     h) Sludge thickener
     i) Sludge drying bed
       Biological Oxidation and Dephenolisation is a near natural treatment of
wastewater by various types of microorganisms like Pseudomonas bacteria for removal
of Phenol, Nitrosomonous & Nitrobacter for removal of Ammonia. The
oxidation/digestion of the pollutants take place in aeration tanks where oxygen is made
available to microorganisms from air to breakdown the toxic substances. This is a
techno-economically viable solution for treatment in confirmation to IS2490-1982.
      The BOD plant was designed for influent water with the following characteristics.
Over a period of time the influent wastewater characteristics were changed due to
closing down of some units in CCD. This resulted in irregular feed of wastewater to
BOD plant which badly affected the growth of microorganisms and efficiency of
treatment of BOD plant. The design data, present level of pollutants at inlet and outlet of
BOD plant with norms are given below;



                                            INLET          PRESENT LEVEL        NORM
 SN.                PARAMETER
                                         DESIGN (mg/L)        ATINLET           (mg/L)

   1.      Waste water flow (m3/hr)        150 - 175           80 - 100            -
   2.      Ammonia                         300 - 350             157              50
   2.      Phenol                          400 - 500             167              1.0
   3.      Cyanide & Thiocyanite           100 - 150           1.5 & 150          0.2
   4.      BOD                               1700                410              30
   5.      Tar & oil                        30 - 40             Traces            10
Waste in Mining, Iron & steel Industry                                              [2.5 / 6 ]


     The wide difference in design data and the present influent characteristics resulted
improper growth/inhibited growth of microorganisms at various stages of treatment in
BOD plant. This has resulted in improper reduction of Ammonia and cyanide and failed
to meet the statutory norms.

3.   Problems Faced In Bod Plant Of Rourkela Steel Plant
     1. Reduction in hydraulic loading
     2. Shock loading of Ammonia in the influent
     3. Improper mixing in equilisation tanks
     4. Improper operation of DAF system and coagulation
     5. Insufficient contact time in Trickling filter
     6. Low pH at second stage aeration
     7. Very low presence of microorganisms in second stage aeration.

4.  Study For Enhancement Of Effectiveness Of Bod Plant, Rsp
    The problems were studied in detail and an action plan is formulated for complete
revamping of the BOD plant so that all the pollutants are treated properly and statutory
norms are met. The various steps being under taken to set right the BOD plant are;
     1.    Constant pumping of waste water from all 3 catch pits of CCD to maintain
           constant hydraulic feed to BOD plant - The pumps are maintained properly
           and constant vigil is kept at all catch pits for continuous pumping of waste
           water to BOD plant.
     2.    Extending the inlet of equilisation tank up to its bottom for thorough mixing &
           equilisation. Earlier the inlet and outlets of equalisation tanks are at same
           horizontal plane which resulted in short circuiting and the main purpose of
           equalisation tank was defeated. The extension of inlet up to the bottom of
           equilisation tank, made uniform mixing of liquor in the tank and short circuiting
           is prevented.
     3.    Revival of DAF unit and using FeSO4 as coagulant in place of alum. - The
           presence of Cyanide & Thiocyanide prevents growth of Nitrosomonous and
           Nitrobacter micro organisms. Ferrous Sulphate removes Cyanide present in
           the wastewater. Earlier Alum was used as coagulant for removal of
           suspended solids. Now alum is replaced by Ferrous Sulphate, which acts as
           coagulant as well as helps in removal of Cyanide. It is established that
           cyanide is removed with the dosage of Ferrous Sulphate with a dosing rate of
           15 ppm.
Waste in Mining, Iron & steel Industry                                              [2.5 / 7 ]


     The reaction of Ferrous Sulphate with Cyanide is given below;
                            Fe+2 + 2 CN-             Fe (CN)2
                            Fe(CN)2 + 4CN-           [Fe(CN)6]4-
                            [Fe(CN)6]4- + 2Fe2+      Fe3[Fe(CN)6)]


         1. Low pH of liquor in second stage aeration - The nitrification reaction makes
            the liquor highly acidic which inhibits growth of Nitrosomonous &
            Nitrobacter. A highly alkaline waste water source is located at Steel Melting
            Shop #2 and the alkaline water is brought to BOD plant by closed pipe line
            and added to maintain optimum pH.
         2. Culturing microorganisms using cow dung and adding in second stage
            aeration tank to maintain sufficient level of microorganisms - Washing out of
            microorganisms at second stage is a common phenomenon observed. To
            maintain sufficient MLVSS concentration, processed cow dung liquor dosing
            is being exercised which has given good results.

5.   Results Of The Study
     The action plan for revamping of BOD plant of RSP has been implemented. The
results show, there is considerable improvement in all parameters as well as good
microbial growth. The pollutant parameters concentration at the outlet before and during
implementation of the action plan are given below;

                                             POLLUTANT CONCN. (mg/L)       NORM
        SN         PARAMETER
                                           BEFORE TRIAL    DURING TRIAL    (mg/L)
         1.   Phenol                       0.06 - 0.32      0.06 - 0.10     1.0
         2.   Cyanide                      0.08 - 0.70      0.14 - 0.20     0.2
         3.   Ammonia as NH3-N              24.2 - 236       1.28 - 35       50
         4.   Tar & Oil                  NOT TRACEABLE    NOT TRACEABLE     10
         5.   COD                            70 - 143         65- 137       250


6.     Conclusion
       The removal of Phenol is very good. Cyanide and Ammonia reduction is achieved
first time since inception after implementation of the action plan. Dosing of Ferrous
Sulphate at inlet to DAF, maintenance of optimal pH & MLVSS concentration at second
stage aeration were given maximum thrust to improve removal of Cyanide & Ammonia
so that statutory norms are met. The treated effluent is recycled back to Coke Ovens for
quenching purpose there by there is no discharge from BOD plant to drain.
Waste in Mining, Iron & steel Industry                                           [2.6 / 1 ]


                    WASTE UTILIZATION & MINIMISATION
                  AT RSP BLAST FURNACES: AN OVERVIEW
                  Shri DD Patra, Shri DM Srivastava, Shri S. Ranade.
                      Rourkela Steel Plant, SAIL,Rourkela-769001



                                         Abstract

      Blast Furnaces being a processor of mineral, generates a number of waste
material during production of hot metal, Slag being the major waste product. Actually
something is termed as waste as long as it has not found a use. Since the ages several
mountains of slag has been created in absence of a viable use. But now not only BF
Slag (granulated) has been an important raw material for Portland slag cement but also
it has found use in several other areas such as marine aquaculture, construction
industry& for insulation purpose (as ground granulated slag). Similarly another waste
product of BF process, the flue dust, recovered during cleaning of BF top gas is used in
basemix the feed for sinter making. A number of actions were taken at R.S.P Blast
Furnaces to minimize waste generation as well as in recycling the waste. Use of
imported coal in blend, increasing HBT, installation of HTP and improving process
parameters to name a few have resulted into lower waste generation where as
installation of CHSGP, Belt Press Filter and improvement in GCP has improved the
recycling of the waste generated. RSP is also implementing an ambitious modernization
plan where waste generation shall be further reduced and all the waste shall be
recycled.

1.    Introduction
      Any industrial unit using natural resources generates a byproduct during
processing which is termed as a waste as long as an use is not found for this product. It
is a fact that no system can be perpetually perfect to prevent generation of a waste, but
the system can be improved to reduce the waste generation to a bare minimum level.
Further, effort must be made to find a use for the byproducts of the system, so that they
can be used as a resource for some other product.
      Blast Furnace is a major consumer of natural resources such as Iron Ore, Coking
Coal, Lime stone, Quartzite etc., besides Air for its Oxygen requirement. It also uses
millions of gallons of water for its process. BF slag is one of the major waste products
of BF, which comes from the gangue material of Iron Ore & Ash of coke. Also the fines
carried over by BF gas & Cooling water is another waste product of BF. Since the ages,
no body knows how many mountains of Iron Ore the Blast Furnaces have swallowed
Waste in Mining, Iron & steel Industry                                           [2.6 / 2 ]


world over and how many mountains of environmentally detrimental slag mountains
they have created. But the       scenario is now changed, natural resources are fast
depleting and no one can have the liberty to throw any thing to the surrounding affecting
our environment. As the old saying goes, “necessity is the mother of invention” or
scarcity brings austerity, soon people have started taking up a number of measures for
optimum utilization of resources, minimum generation of wastes or waste recycle
measures and finding a number of use for its waste products. Rourkela Steel Plant Blast
Furnaces have also done its part in minimising waste generation or recycling of its
waste products.
     A large number of measures were undertaken at BF shops in minimizing
production of slag or otherwise converting the slag to usable form to be used as a
resource for cement plants. Also measures were taken to minimize & recover the solid
waste lost through BF gas & from Cooling water to the maximum possible level. All
attempts have been put to minimize & re-circulate the cooling water in such a way that
the unit is almost self sustaining on water requirement.
    A number of actions were also taken to minimize the return fines arising from the
raw material conveying system and recycling of the same through the system. Details
of waste generation, minimization measures & their recycle are enumerated in this
paper.

2.     Blast Furnace Wastes
       Although a number of minor waste is generated in BF process the only major
waste is the BF slag which is at present generated ~ 395 Kg/THM at RSP. The flue
dust separated from BF gas ~ 5 – 10 Kg/THM, gas cleaning plant clarifier sludge and
filter sludge ~ 0.3 – 0.5 kg/THM are the other BF waste of some prominence. The BF
gas which is another byproduct of BF process is never considered as a waste because
it is fully utilized in an integrated steel plant because of its fuel value. However,
minimizing losses of this gas or optimum generation of this gas is part of waste
management system in Blast Furnaces. Belt return fines and D.E system fines are
though very less, still considered as a waste in BF unless recycled through a proper
handling system. Under this back drop BF department adopted a 3 prong waste
management system in the shop such as:
     a)    Reducing the waste generation;
     b)    Converting the waste into recyclable form;
     c)    Recycle the waste.
Waste in Mining, Iron & steel Industry                                                                           [2.6 / 3 ]


3.  Efforts to reduce waste generation at Blast Furnace
    A number of steps were taken over the years to reduce generation of various
wastes such as BF slag, Flue Dust, BF gas & spillage water etc.are elaborated as
under:

a)    Reduction in generation of Blast Furnace Slag:
      The amount of slag generation per ton of Hot Metal depends on mainly the coke
rate (coke ash being the major contributor to slag generation) and the gangue material
in iron bearing materials such as Iron Ore lump and sinter used for Iron making.
Therefore, a large number of steps have been taken at RSP Blast Furnaces to reduce
coke rate, important among them are (1) increasing the Hot Blast Temperature (2) using
more imported coal in the blend to get coke with lower ash (3) optimizing & improving
furnace operating parameters (4) improved cast house practice (5) use of 100%
screened iron ore & sinter (6) introduction of high top pressure & oxygen enrichment in
BF #4. The coke rate at RSP has been reduced considerably from 680 Kg/THM to 580
Kg/THM over last decade ( see Fig.1). The other factor contributing to reduction in slag
generation is the gangue content in iron ore & sinter. Ore beneficiation at mines,
blending, bedding & screening at our OBBP has helped reducing the gangue content in
the raw material as shown in Fig.2.


                                   Coke rate Trend (Kg/THM)
       700



       675



       650



       625



       600



       575



       550
             97-98    98-99   99-00   00-01   01-02    02-03   03-04       04-05     05-06     06-07    07-08

                   97-98   98-99   99-00   00-01   01-02   02-03   03-04     04-05     05-06    06-07    07-08
       Coke Rate    678     663     668     656     647     611     633       633       607      577      578



                                                   Figure-1
Waste in Mining, Iron & steel Industry                                                                               [2.6 / 4 ]



                                             % GANGUE INPUT TREND


        50

        49

        48

        47

        46

        45

        44

        43

        42

        41

        40
             97-98     98-99     99-00     00-01     01-02     02-03     03-04    04-05    05-06    06-07    07-08


               97-98     98-99     99-00     00-01     01-02     02-03    03-04    04-05    05-06    06-07   07-08
       Gague    47.8      48.4      48.6      48.1      48.1      46.2     46       47.7     45.1     43.6   44.57



                                                        Figure-2


     The above efforts have resulted into reduction in slag generation (slag rate) per ton
of hot metal to ~ 395 Kg/THM from ~ 410 Kg/THM over the years as shown in Fig.3.

(b)   Reduction in generation of flue dust :
      The amount of flue dust carried over by the out going BF top gas depends on the
dust content in the input materials, strength of the input materials and efficiency of the
furnace operation besides the top pressure of the furnace. After installation of high top
pressure system in BF # 4 in Sept.2005, the generation of flue dust from BF # 4 has
come down considerably from 10 Kg /THM in 2005-06 to 3 Kg/THM in 2007-08. To
minimize the fines/ dust input into the furnace we have ensured use of 100% screened
ore lump and ~ 99% screened sinter. Dumping of direct iron ore lump from mines in BF
High Line have been stopped since 2005. Up-gradation of sinter screens and improved
maintenance practice has ensured use of ~ 99% screened sinter in our burden as
shown in Fig.4. After installation of I.C. Screens for coke screening, coke screening
efficiency has gone up resulting into lower coke fines into the furnace. Another
modification done to improve coke screening is installation of coke fines feeder which
not only enable utilization of full screen area but also avoids launder jamming by feeding
Waste in Mining, Iron & steel Industry                                                                                                 [2.6 / 5 ]


the coke fines to launder by a vibrator. Improving the strength & hardness of input
materials particularly that of coke & sinter reduces fines generation thereby reduces the
flue dust carried over by the outgoing BF top gas. Use of more imported coal in blend
and use of PBCC has helped us to improve the coke hardness ( i.e. M10 value) over the
years. Similarly, improvements in sinter plants has resulted into sinter having good
strength ( DTI value). The coke M10 value & sinter DTI value over the years are given in
Fig.5 &6.
                                            SLAG RATE TREND (Kg/THM)




                  430




                  405




                  380
                        97-98    98-99    99-00    00-01     01-02     02-03         03-04     04-05     05-06      06-07     07-08

                           97-98    98-99    99-00    00-01    01-02         02-03     03-04     04-05    05-06      06-07    07-08
                 slag rate 400       410      414      409      432           411       404       402      393        394      406




                                                               Figure-3

                                                           % SINTER SCREENED

                  110



                  105



                  100



                   95



                   90



                   85



                   80
                        97-98   98-99     99-00    00-01     01-02     02-03         03-04     04-05     05-06      06-07     07-08

                                97-98    98-99    99-00    00-01     01-02     02-03     03-04    04-05     05-06     06-07    07-08
                 %Sint Screen    82.8     84.1     95      96.25     97.68     93.85     95.94    98.73     98.37     98.99    99.21




                                                               Figure-4
Waste in Mining, Iron & steel Industry                                                                                                 [2.6 / 6 ]



                                                          COKE M-10 VALUES

                      9.4


                      9.2


                        9


                      8.8


                      8.6


                      8.4


                      8.2


                        8
                            97-98     98-99     99-00     00-01    01-02    02-03    03-04    04-05     05-06    06-07     07-08

                           97-98       98-99     99-00     00-01    01-02    02-03    03-04    04-05     05-06    06-07     07-08
                      M-10 8.85        9.05      8.84      8.67     8.67     8.44     8.57     8.76      8.56     8.44      8.65



                                                                    Figure-5



                                                            SP-I DTI VALUES
                 75

                 74

                 73

                 72

                 71

                 70

                 69

                 68

                 67

                 66

                 65
                        97-98       98-99      99-00     00-01     01-02    02-03    03-04     04-05     05-06     06-07      07-08

                       97-98    98-99          99-00     00-01     01-02    02-03     03-04     04-05     05-06     06-07      07-08
                DTI    70.2     70.1           70.1      71.9      71.5     71.3      73.1      71.1      70.7      70.7       71.3




                                                                    Figure-6


     Efficiency of the furnace operation such as steady blowing, prevention of hanging
& forced slips, and minimizing down-time can reduce the flue dust losses through BF
top gas. Improved equipment availability & input materials, better cast house practice
Waste in Mining, Iron & steel Industry                                                                        [2.6 / 7 ]


introduction of mix charging system and furnace movement control by differential
pressure control has helped us to improve furnace operation & contribute to lower
generation of flue dust as shown in figure-7.

                             RATE OF FLUE DUST RECOVERED (Kg/THM)


        35



        30



        25



        20



        15



        10



         5
             97-98   98-99   99-00   00-01    01-02   02-03   03-04       04-05     05-06    06-07    07-08


                  97-98   98-99   99-00   00-01   01-02   02-03   03-04     04-05    05-06    06-07   07-08
       Fluedust    26      20      30      18      15      18      15         7        9        7       7




                                                  Figure-7



c)     Reducing loss of BF gas:
       Theoretical generation of BF gas per ton of skip coke burnt is ~ 1.2 times of Air
blown in Blast Furnaces. The more nearer to this value one is, the more is the efficiency
of operation i.e. less loss of BF gas. There is a steady increase in BF gas generation
per ton of skip coke in RSP BF implying reduced loss (See Fig.8). It is the result of a
number of systematic actions taken to improve gas yield & reduce gas losses. Among
the important ones are; installation of BLT charging systems with excellent sealing
arrangement, replacement of aging goggle valves, bifurcation of gas lines to facilitate
maintenance without shut-down of all furnaces, monthly inspection of leakage points &
its liquidation during shut down days. Timely cleaning of gas lines & repair of GCP units
has also contributed to improved gas yield. Improved furnace operation & optimization
of furnace operation also contributed considerably to improved gas yield. As per the
losses on account of bleeding, modifications in power plant boiler burners, cleaning of
Waste in Mining, Iron & steel Industry                                                                                         [2.6 / 8 ]


clean gas line and increasing gas pressure in stove gas line has contributed to
increased consumption of BF gas & less bleeding.




                                      BF GAS YIELD(NM3/TSC)
            3000


            2950


            2900


            2850


            2800


            2750


            2700


            2650


            2600
                   97-98    98-99     99-00     00-01     01-02     02-03     03-04     04-05     05-06     06-07     07-08

                    97-98     98-99     99-00     00-01     01-02     02-03     03-04     04-05     05-06     06-07    07-08
          BFG Yield 2628      2719      2706      2900      2811      2893      2826      2630      2734      2883     2879




                                                           Figure-8



d)    Reduction in water consumption or reducing the water loss at BF:
      Blast Furnace requires around 13,000 m3/hr cooling water for cooling the furnace
lining, tuyer coolers, Hot Blast Stove Valve coolers, GCP scrubbers & for ESP flushing
requirement etc. An excessive requirement of makeup water to the tune of 1200 to 1400
M3/hr was required in the water circulation system of GCP due to inadequate cleaning
of return water in the Filter House, non availability of required number of cooling towers,
overflow & leakage at a number of points, which had led to excess requirement of
make-up water during the 1990’s. But a number of steps have been systematically
taken over a period of times to minimize water losses and now BF department is almost
a self sustaining closed loop unit requiring ~ 300 m3/hr to 400 m3/hr makeup water to
take care of the losses including the evaporation losses. The trend of make up water
requirement over the decade is shown in Fig.9.
Waste in Mining, Iron & steel Industry                                                                                 [2.6 / 9 ]


                           MAKE UP WATER REQUIREMENT (m3/hr)
           1500



           1300



           1100



            900



            700



            500



            300
                  97-98   98-99    99-00    00-01     01-02     02-03    03-04    04-05   05-06       06-07    07-08

                       97-98      98-99    99-00    00-01     01-02   02-03   03-04   04-05   05-06    06-07   07-08
          Makeup water 1438       1276     1037      801       794     559     480     431     411      401     377




                                                            Figure-9


       Among the major initiatives taken for reducing water losses is, the installation of
highly efficient and environment friendly Belt Press filter in place of vacuum disc filter
for filtering the clarifier underflow water. Efficient removal of sludge by belt press filter
has eliminated frequent draining of clarifier underflow water thereby substantially
reduced the water losses on this count. Revamping & up gradation of 6 cooling towers
in last 2 years has gone a long way in reducing additional water requirement as well as
minimizing the losses also. After connection of a pipe from BF cooling tower inlet pipe to
High Pressure pump # 1,2 & 3, excess water overflow from BF cooling towers could be
diverted and overflow/wastage avoided. This has resulted into saving of substantial
mount of water wastage. Besides the above steps, replacement of leaking valves &
repair of leaking pipes was carried out regularly to save water.
     Efforts to convert the waste into a recyclable form :
     As mentioned above earlier, as soon as a waste finds an user it is no more a
waste, it has become a resource. Therefore, it shall be a beauty if all the waste is
converted into a resource & is put to use. With this philosophy in mind, all tempts have
been made to convert our major waste i.e. BF slag into granulated slag which is a major
raw material for cement plants. The actions taken at our plant over the years to increase
the percentage of slag granulated is detailed below:
Waste in Mining, Iron & steel Industry                                                                                     [2.6 / 10 ]


1.    Increasing % of slag granulation:
      Upto the 1990’s BF liquid slags were carried in steel slag pits to external slag
granulation plant, ~3 KM away from the cast house & poured there for granulation. % of
liquid slag granulated was ~ 50 only. The pouring method had the handicap of several
bottlenecks such as hard crust formation on top of the slag pot, a number of problems in
slag cars making the pot unsuitable for pouring and inability to pour the entire slag in the
slag pot. Moreover, due to various logistic problems & poor availability of slag pots for
casting, many a times slag pots were directly dumped out-side instead of pouring at
slag granulation plant leading to lower % of liquid slag granulation.
      A systematic action plan has been implemented over the years to improve % of
slag granulation. First among the project implemented is the installation of cast house
slag granulation plant of BF#4 in 1995 followed by BF#1 in 2005. It is worthwhile to
mention that due to lack of experience in running & maintaining a Cast House Slag
Granulation Plant, various furnace problems, absence of a good cast house practice
and few major breakdowns of INBA #4 equipments, availability of BF#4 CHSGP was
not satisfactory until 1997. But thereafter, availability of CHSGP remains more than
90% and ~ 95% of the liquid slag generated from BF#4 is granulated. With good
experience of running & solving of problems faced in INBA #4, we could commission &
stabilize BF #1 INBA CHSGP quickly in Aug.2005. By Sept.2005 liquid slag granulation
from INBA CHSGP exceeds 90% from the level of 60% in the 90’s.The results are
shown in Fig.10.

                              % OF SLAG GRANULATED IN CHSGP
              100


               95


               90


               85


               80


               75


               70


               65


               60
                    97-98   98-99     99-00     00-01     01-02     02-03     03-04     04-05    05-06    06-07    07-08

                    97-98     98-99     99-00     00-01     01-02     02-03     03-04    04-05    05-06    06-07   07-08
             %chsgp 62.15      89       99.4      94.5      94.1       97       94.2     97.3     87.8     97.8    88.1


                                                           Figure-10
Waste in Mining, Iron & steel Industry                                                                      [2.6 / 11 ]


      Liquid slag from BF #2&3 still continues to be sent to external SGP for granulating
the slag. A number of action have been taken to improve the % of slag granulated at
SGP from a level of 40 to 50 during the 90’s to ~ 70% in 2007-08. Introduction of water
dumping of skull slag pots instead of knocking, has brought in revolutionary changes in
improving slag pot availability, providing clean slag pots for casting, avoiding cracking
of slag pots & damage to slag cars & their tilting drives . This has facilitated availability
of pots for proper lime coating & enhanced slag pot carrying capacity resulting into more
slag pouring per pot at SGP.
     Besides the above, introduction of super finish steel slag pots and & improved
lime coating by using CP#II lime fines and 5 coats of lime instead of earlier 3 coats has
increased the % of slag poured at SGP considerably. Introduction of CHSGP at BF#1 &
#4 also ensured quick disposal of slag loads to SGP (because of few slag load
generation) thereby minimizing hard crust formation & maximum pouring. Dumping of
cast house mucks in slag pots has also been discontinued since 2004 which helped in
preventing hard crust formation & the slag loads are now easily pourable at SGP.
      Improved cast house practice such as minimum 3 casts/shift, minimization of slag
pot pushing during castings and higher metal/slag temperature has helped in avoiding
hard crust formation and therefore, more % of slag pouring at SGP.The trend of % slag
granulated at SGP in the last decade is shown in Fig.11. It is heartening that the above
actions have yielded good dividend and % of over all liquid slag granulated at BF has
been increased to above 80% & that of INBA at SGP to more than 95% as shown in
figure-12.

                                           % OF SLAG GRANULATED IN SGP


             100


              90


              80


              70


              60


              50


              40


              30
                   97-98   98-99   99-00    00-01   01-02   02-03   03-04   04-05   05-06   06-07   07-08



                   97-98   98-99   99-00    00-01   01-02   02-03   03-04   04-05   05-06   06-07   07-08
            SGP     36.5    41.3    57.5     54.4    42.9    44.7    45.5    49      57.7    81.7    70.6



                                                     Figure-11
Waste in Mining, Iron & steel Industry                                                                               [2.6 / 12 ]



                                    % OF TOTAL SLAG GRANULATED IN B.F


          100



           90



           80



           70



           60



           50



           40
                97-98   98-99   99-00     00-01    01-02   02-03    03-04     04-05    05-06    06-07       07-08



                          97-98   98-99    99-00   00-01   01-02   02-03    03-04   04-05   05-06   06-07    07-08
         %slag granulated 48.3    57.2      74     72.1    64.4    62.4     60.2    63.2    70.9    89.4     87.5


                                                      Figure-12



2.    Increasing flue dust recovery:
      The flue dust recovered from the BF top gas contains ~ 40% coke fines & 25-30%
iron bearing material thereby making it suitable as a raw material for sinter-making. But
because of handling problems associated with this material, this was simply thrown
outside the plant as a waste prior to installation of our ore bedding & blending plant.
After commissioning of OBBP in 1997, preparation of base mix, the prime feed for sinter
making, started using a mix of iron ore fines, coke fines, lime stone & dolo fines. This
has rendered excellent scope for recycling of the flue dust recovered at BF by mixing
along with the base mix feed. Therefore, the more flue dust recovered from the top gas
means more utilization of wastes which otherwise would have been lost through top gas
or return water.
      A large number of measures have been taken in BF GCP to recover the flue dust
to the maximum extent possible from the top gas and return water. Important among
them are modification & replacement of high efficiency scrubber nozzles for efficient
washing of top gas, regular drying of dust catchers to prevent higher dust carry over
along with top gas, systematic capital repair of ESPs & cooling towers to improve the
efficiency, replacement of raw gas & clean gas goggle valves for enabling capital repair
of ESPs etc. The dust content in the BF clean gas is the indicator for efficient recovery
of flue dust from top gas. Over the years the dust content in our clean gas has come
Waste in Mining, Iron & steel Industry                                                                          [2.6 / 13 ]


down considerably from 15-16 mg/Nm3 to 5 mg/Nm3. Similarly, whatever flue dust was
washed through washers / scrubbers & ESPs is also recovered by settling in clarifiers &
then by filtering. The efficiency of recovery of dust from the clarifier water has been
enhanced by introduction of chemical dozing along with installation of Belt Press filter in
place of vacuum disc filter. Recovery of dust from Belt Press filter is now 15T/day in
comparison to 5T/day in case of Disc filter. Revival of clarifier #3which was down for
several years by in-house innovative method has also helped in the effort for recovering
more dust from washing water and has also enhanced clarifier availability. Strict
implementation of clarifier cleaning schedule ( i.e. cleaning of each clarifier once in a
year) has also helped us in increasing the dust recovery. The trend of cleanness of BF
gas & dust recovery is given in Fig.13 which reveals that there is tremendous
improvement in recovery of flue dust from top gas.

                       DUST CONTENT IN BF CLEAN GAS(mg/Nm3)

          19


          17


          15


          13


          11


           9


           7


           5
               97-98   98-99   99-00   00-01   01-02    02-03   03-04       04-05     05-06    06-07    07-08

                    97-98   98-99   99-00   00-01   01-02   02-03   03-04     04-05    05-06    06-07   07-08
         BFG Dust    12.6    14.8    11.7    8.7     7.8      9      15.9      7.7      7.6      6.9     5.8


                                                    Figure-13

4.   Measures to recover & recycle the wastes in stock house
      The common wastes in raw material handling system & stock house are the belt
return fines and the D.E system recovery dust. Fixing of modified scrappers & a reliable
fines handling system enabled us to recover the belt return fines which is then recycled
through base mix feed in OBBP.In absence of an effective DE system, lot of dust is lost
by polluting the air. Revamping & upgradation of DE system in our BF #4 stock house in
2005 has not only helped us to recover substantial amount of dust but also made it
easier to re-use in base mix feed. This year too the DE system of BF#1,2 &3 Stock
House has been revamped & made effective. While the proposal for installation of dry
Waste in Mining, Iron & steel Industry                                           [2.6 / 14 ]


fog system for suppression of dust in stock house is under implementation the proposal
for implementation of cast house de-dusting system is under active consideration of
management.

5.    Measures to recover & recycle the Cast House runner losses & metal kishes
      Cast house waste generation is largely due to the runner loss and muck generated
while preparing the Cast House. Metal kisses generated during casting is also another
metallic waste. The earlier practice at Rourkela had been to collect all the iron jams in
scrap boxes and rest of the generation in muck boxes. Iron jams were taken by
dumpers to scrap & salvage unit for processing the same to be used in SMS, whereas
the muck boxes were either emptied into slag pots for dumping outside the plant or
taken by tippers to be dumped in Scrap & Salvage unit. The practice of sending mucks
through slag pots has been stopped since 2004; all the iron jams and slag mucks
generated in Cast House is sent to our Scrap & Salvage department where metallic
portion is reclaimed from the waste and used in Blast Furnaces as BF fines.
     While effort is made to recycle the Cast House wastes a number of steps have
been taken to reduce muck generation of Cast House. Important among them ; use of
high life trough mass which made it possible to repair the trough once in a month in
comparison to 2 to 3 times in a month earlier. Holding of bypass continuously for over a
month has eliminated bypass runner losses. Use of castable iron runner, and tilting
runner in BF 3 & BF #4 has reduced iron runner losses to almost zero.     Splash
guards are provided by the side of iron tracks to catch metal splashing which is then
recovered in large pieces to be used as scrap. Metal kisses on the Cast House or from
the ground is dosed and sent to SSD for reclamation.

6.     Future Plan for Waste minimization
       With installation of BF#5 having modern state of the art technology, reconstruction
of BF#1 with high top pressure & CDI in BF 1 & 4 Slag rate can be reduced to as low as
300 Kg/THM from today’s 400 Kg/THM. Installation of cast house slag granulation plant
in all furnaces shall ensure 100% granulation means full utilization of the slag in cement
plant. RSP is also shortly building a cement plant with joint venture to take care of the
entire granulated slag produced from BF. In addition to this commissioning of closed
loop demineralised water circuit, power full D.E systems in material handling section,
use of runner covers, castable troughs & cast house de-dusting system shall minimize
waste generation substantially by 2012 at RSP BF.

***About the Authors:
     The authors are Sri D.D.Patra AGM BF(O), Sri D.M.Srivastava DGM BF(O) and Sri
S.Ranade GM I/C (Iron) SAIL,Rourkela Steel Plant,Rourkela-769001.
Waste in Mining, Iron & steel Industry                                                   [2.7 / 1 ]


            RECYCLE MANAGEMENT OF WASTE REFRACTORY
                    AT ROURKELA STEEL PLANT

                        S.K.Bandopadhyay, P.K.Ray Choudhury*
                        D.Ghosh, S.K.Vadher, S.Chandrasekaran
               (*The author is from SAIL, R&D Centre for Iron & Steel, Rourkela Centre
                        Others are from SAIL, Rourkela Steel Plant, Rourkela)



      The refractory materials are generally multiphase ceramic products which, in
industry, are subjected to severe conditions of use (high temperatures, severe thermal
shocks, etc.). By definition, a material having the ability to retain its physical shape and
chemical identity when subjected to high temperatures is called refractory. The iron and
steel industries are the principal consumers of refractory products.
      The structure of a refractory material is composed of a mixture of aggregates
whose size ranges from micron to several mm, surrounded by a matrix, containing finer
grains (of size lower than 0.1 mm) and eventually a binder. Different types of refractory
materials are used for different application, specific to the condition of use. The life time
in service varies from few hours to more than twenty years. The specific consumption
of refractories per tonne of steel in our country varies from 10 to 20 kg. This gives an
idea of the importance of this kind of materials and the activities which surrounded
them. In iron and steel industry, refractories are present at each step of production (e.g.
lining of ladles, converters reheating furnaces etc ) and some of them contain carbon.
       In the past, refractories producers and consumers thought of spent refractories on
a disposable commodity – once removed from service, the material was simply land
filled. The lack of environmental awareness coupled with the low cost of disposal,
inexpensive raw materials, uncertainty about the quality of recycled products and the
complexity of recycling operations led to the widespread belief that recycling was just
not cost effective and too troublesome to worry about. However, more recently due to
use of costly raw material in refractory product coupled with increasing disposal cost
and stringent environmental issues forced the industry to take a deeper look into the
problem. Moreover, established resources are being exhausted and discovery of new
ones are getting harder and more expensive. The capacity of the earth to assimilate
more waste is also nearing its limits. The increase in production of steel in a
sustainable fashion will only be possible with the circulation of resources.
     The concept of refractory recycling involves 3Rs (Reduce, Reuse and Recycle).
Reduce refers to decrease refractory consumption per tonne of steel means, reduce
refractory wear while use. “Reuse” refers to the utilization of spent refractories in
Waste in Mining, Iron & steel Industry                                             [2.7 / 2 ]


production process e.g. Magnesia-Carbon spent refractories as slag conditioner in
electric arc furnace steel making or as a patching material for the eroded portion of BOF
lining (charge pad). “Recycle” refers to the reuse of spent refractories after processing.
Mostly the recycled grain thus generated are used along with virgin material and then
used either as monolithic refractories or repair material or as shaped product in non
vulnerable areas of metallurgical vessel lining.
      Several kinds of refractories are present in every furnace. When these refractories
are subjected to demolition, they are discharged in a mixed state. In this mixed
condition, spent refractories are not suitable for recycling. The demolished spent
refractories are sorted for example, into MgO type or Al2O3 type refractories. After
sorting, the clean materials are reduced in size by traditional crushing, grinding and
screening operations. During the entire sizing process, the materials undergo
conditions magnetic separations. Samples are then taken and extensive quality control
tests conducted to determine chemical and physical compliance with previously
established standards. The materials are then packed by type and particle size range
and stored for future recycling/ reuse depending on their type.
      In Rourkela Steel Plant, continuous efforts are being made towards reduction in
specific consumption of refractories per tonne of steel by improving the lining life of two
major refractory consuming units e.g. BOF and steel ladle. In BOF, lining life increased
from 995 (Avg. life of 2001-2002) to 4001 heat (Avg. life of 2007-2008) with in-house
pitch bonded MgO-C bricks and thereby total number of campaigns per year decreased
from eight to three and hence generation of waste refractory decreased by more than
60%. In the case of steel ladle, lining life increased from 60 heats to 100 heats with
purchased MgO-C bricks on performance guarantee basis from different suppliers. Here
also the requirement of total refractories per year decreased significantly for the same
level of production. Another area, where generation of waste refractories has been
reduced drastically is in 140T hot metal ladle. The number of relining and repair per
annum decreased from 28 to 11 and 213 to 178 respectively when compared 2005-
2006 data with 2007-2008 till date, although the production of hot metal increased from
1.77MT(2005-2006) to 2.2MT(likely to achieve for 2007-08).
     Regarding “Reuse” of spent refractories only a portion of dismantled MgO-C lining
is used as a patching material to take care of the localized preferential wear areas of
BOF. Rest of the spent MgO-C refractories is sold outside. The bricks dismantled from
safety lining of different metallurgical units are also reused after proper sorting where
ever possible. Attempts were made to reuse waste slide gate plates as impact pad of
tundish.
      The lack of space and quick equipment turn around times in most cases, selective
lining dismantling is usually not feasible and sometimes not even local sorting can be
Waste in Mining, Iron & steel Industry                                         [2.7 / 3 ]


done due to lack of available space and manpower. Moreover, all generated spent
refractories of different suppliers are to be stored separately and also dealing of
unknown material for recycling may be difficult. In the absence of dedicated recycling
plant at RSP, most of the spent refractories generated are either sold or dumped
outside.
Waste in Mining, Iron & steel Industry                                          [2.8 / 1 ]


MANAGEMENT OF SOLID AND LIQUID WASTES AT COKE OVEN AND
      BY PRODUCT PLANT OF BOKARO STEEL PLANT
                                         K.K.Sanyal
                                     Astt.General Manager
                                      Bokaro Steel Plant

     The waste management is an industry makes it cost effective and its productivity
increases by recycling wastes. Thus approaches to ‘ZERO ‘ WASTE. By proper waste
management pollution reduces & in turn helps social & economic development.
      Various liquid and Solid Waste (Hazardous and non-hazardous) are being
generated in CO & BPP of Bokaro Steel Plant. The secured engineering landfill ( Fig –
1) of 125 meters x 30 meters x 4 meters has been made for disposal of hazardous
wastes of CO & BPP and mill area. Liquid wastes are Ammoniacal liquor generated
during coke oven gas condensation and waste water generated during scrubbing of C.O
gas in other units of By-product Plant.
      Ammonia rich waste water is treated in Ammonia still to take out free ammonia
which goes into saturator for enhancing Ammonium Sulphate production. Other waste
water with ammonia, phenol , cyanide, tar oil and grease is treated in B.O.D plant &
treated water is used in coke quenching. Thus waste water is re-used fully in the coke
making process only. Table 1 & 2 shows the characteristics of waste and treated water
of B.O.D plant.
     In Table –3 solid waste materials gives an idea of solid wastes management
system either by re-cycling/ re-using and earns revenue by selling to outside parties,
thus approach to ZERO Waste. For some wastes , market is being explored. Damaged
conveyor belts generated are cut into small lengths & sell to market . Metallic wastes
are being charged in Steel making system in SMS converter. Refractory bricks
generated are being used inside         plant for some secondary purposes. We have
developed lubricating oil recycling system where no waste generated & it also satisfies
ISO 14001 : 2004 EMS guidelines. ( BSL already certified ).
    Thus we the collectives of CO & BPP of Bokaro Steel Plant are improving in
wastes management system, we will continue till we achieve ZERO WASTES.
Waste in Mining, Iron & steel Industry                                                          [2.8 / 2 ]


Table-1
    Ammonia                  : 400 mg/liter
        Tar & grease         : 500 mg / liter
        Cyanide              : 2 mg / liter
        PH                   :8-9
        Phenol               : 400 mg/liter

Table-2
    Ammonia                  : ≤50 mg/liter
        Oil & Grease         : ≤ 5.0 mg/liter

        Cyanide              : ≤ 1.0 mg/liter

        PH                   : 7-9

Table-3
 S.no        Wastes                              Qty/Yr     Management                    Rev.
                                                   MT       System                    (Rs.in Lakh)
 1.          Decanter sludge                      6000      Mixed     with     coal        ----
                                                            blend
 2.          Acidic   Tar   from      Amn.        2400      Sale to parties              12 .00
             Sulphate plant
 3.          Regenerated Acid                     250       Market to search               -
             sludge
 4.          Tar muck with Sand                   1200      Disposal to HAZ. W.            -
                                                            PIT
 5.          B.O.D                              1200 Nos.   Return & re-se             No waste
             POY JAR
 6.          Sulphur sludge                      300 MT     To HAZ W. PIT                  -
 7.          Used Conveyors                                 Recycle       through         No
                                                  ------    store for auction            Waste
 8.          Used electrical cables                         Re-use for plant              No
                                                   -----    purpose                      Waste
 9.          Used rubber hose pipes             48,000 Kg   Can be sold to party
                                                            for re-use
                                                                                          ---
 10.         Spent alkali (2-3 %conc )           360 MT     Used in HAZ .W PIT             -
                                                            to maintain pH of pit
                                                            water.
 11.         Used lubricating oil                  ----     Re-cycled fully               No
                                                                                         Waste
 12.         Pond Breeze                          2000      Used in Sinter Plant          No
                                                   MT       & B.F.                       Waste
Waste in Mining, Iron & steel Industry                                            [2.9 / 1 ]


   CHALLENGES AND SOLUTIONS FOR UPGRADING INDIAN IRON
         ORES TO OPTIMIZE MINING AND STEEL PRODUCTION

                                         Satyabrata Mishra


     Abstract: Mineral processing is characterized by a constant adaptation to
changing raw materials and market conditions. It is the link between the mined raw
material and a marketable product. As a lot of high grade reserves are exploited, a
steady deterioration of raw material quality can be observed. At the same time, the
customers requirements for product purity and consistent quality increase.
     This general scenario has been well addressed on various occasions in respect to
indian iron ore, e.g. that less than 10 % of the reserves are high grade lumpy reserves
as well as the economic benefits of using high grade, low silica and alumina
concentrates in blast furnaces. So beneficiation techniques for iron ore are becoming
very important in order to achieve a maximized utilization of ore resources and to
optimize the down stream value chain.
     Allmineral has been engaged in hematite iron ore beneficiation with its gravity
separators for more than 10 years. Various installations with jigs for lump and fines as
well as upstream separators for fines are in operation in Australia and South Africa. Low
grade run of mine and/or dump ores are being processed with alljig®- and allflux®-
separators as the core equipment. The biggest of it´s kind in South Africa with 4.000 tph
capacity and 24 alljigs installed.
     The lecture describes the technology in use, the beneficiation characteristics of
various Indian iron ores with special respect to ores from the south indian Bellary area
and the impact of their characteristics on the process technology and achievable grades
and yields. In comparison with Orissa ores southern Indian ores are typically finer
disseminated, which results in the need for finer grinding before being separated.
Although the initial capital and operating costs are relatively high, at actual and
expected future price levels it´ s still a very economical process .
     The data presented show the specific advantages of jigs and upstream separators
on iron ore upgrading due to the possible high gravity cuts and the easy and low
operating costs. WHIMS are an additional option for the recovery of ultrafine Hematite .
These technologies provide a value addition to the development of the Indian Iron Ore
Industry, including the southern parts.
Waste in Mining, Iron & steel Industry                                             [2.9 / 2 ]


                 Challenges                                  Solutions

1    steel production is projected to    - adaption and development of technologies
     double within next 10 – 15 years      for providing steh steel industry with the
     in India                              required iron ores, both in quantity and
                                           quality




2    consequently iron ore production    - maximize the utilization of the ore reserves
     has roughly to be doubled in this
     period



3    only 10 % of the reserves are       - the key to success, mineral benefication
     high grade (lumpy) reserves


4    provide the steel industry with the - follow the required “classical” steps
     demanded quantity and quality


5    quantity becomes an issue in        - mineralogical characterization
     respect to sustained reserves


6    quality becomes one keypoint for - evaluate the results regarding possible
     improving the productivity of steel quality and yields as well as associated costs
     making


7                                        - lab (and pilot plant) test work



8                                        - make business plan
Solutions to Wastes in Mining, Iron & Steel Industry                                  [3.1 / 1 ]


                            “BF SLAG” AND “SMS SLAG”
                      UTILISATION IN BOKARO STEEL PLANT

                                   R.P. Singh & R.G. Segaran
                                 Environment Control Department
                                        Bokaro Steel Plant
                                    Steel Authority of India Ltd



                                          Abstract
      Environmental legislation and regulations and the economics of disposal are
directing the steel industry to look for ways of minimising the generation of wastes and
maximise recycling and reuse of collected wastes. The biggest part (about 70% - 80%)
of solid waste arisings in an integrated steel plant, is metallurgical slag, which is utilised
to a large extent in the cement industry and for road and civil constructions.
       At BSL , presently the 51 % BF slag is granulated and sold to nearby cement
industries. However , nowadays the cement industries prefer dry flyash fom power
plants for making blended cement, to cut the cost of grinding of Granulated BF slag .
Thus there is a need to look for other alternative routes for increasing BF slag
utilization.
     Production of “Ground Granulated BF Slag” (GGBFS) and Air cooled BF slag
aggregates for construction industry are the promising avenues for enhancing the BF
slag utilization. Government should encourage everyone; Steel Industry , ready-mix
concrete companies, builders, contractors, engineers, and architects; to use GGBFS,
thus producing better concrete as well as saving energy and reducing the CO2
emissions in the environment.
      BSL has achieved 96 % utilization level in SMS slag . BSL is processing the SMS
Slag in various fractions. 0-5 mm slag is being charged into Sinter Plant replacing
equal amount of flux . Similarly 10-40 mm size are being used in SMS and BF. The
entire road of Plant and Township are being repaired by 5-10 mm and 10-40 mm size
LD slag. BSL is having around 400 Kms of Railway Track for which 20-65 mm size LD
slag is being spread replacing conventional stone ballast . BSL is also supplying
processed LD slag to IISCO Steel Plant, Burnpur which is being charged in Blast
Furnace, inturn cutting down fresh flux consumption.
   Directions to the concerned in Central Govt and in State Govts. Agenicies like
CPWD, PWD, NHAI, Railways , etc, to specify the use of Slag Cement / GGBFS/ BF
Solutions to Wastes in Mining, Iron & Steel Industry                                              [3.1 / 2 ]


and SMS slag aggregates, etc; in construction activities, will go a long way in meeting
the utilization targets of metallurgical slags from Integrated Steel Plants in India.

1.   Introduction
     Environmental legislation and regulations and the economics of disposal are
directing the steel industry to look for ways of minimising the generation of wastes and
maximise recycling and reuse of collected wastes.
     The biggest part (about 70% - 80%) of solid waste arisings in an integrated steel
plant, is metallurgical slag, which is already utilised in the cement industry and for road
and civil constructions. The chemical analysis of the above stated Metallurgical Slags
(BF slag and SMS slag) are given in Annexure-1.
    The Generation and Utilization of Solid Waste in the financial year 2006-07 at
Bokaro Steel Plant is given in Table-1.
                                                 Tabe-1
                 Solid Waste Generation and Utilisation in BSL ( 2006-07)
                    Solid Wastes Generation (T)             Utilisation (T)       % Utilisation
     BF Slag                               17,43,345               7,11,471              41**
     SMS Slag                               3,97,420               3,30,631              83**
     Mill Scale                              76,393                 76,393                100
     ESP Dust                                25,377                 25,377                100
     Flue Dust                               62,205                 62,205                100
     Acetylene Sludge                         3,546                  3,546                100
     Coke Breeze                            3,92,053               3,92,053               100
     Refractory waste                        12,000                  6,000                50
            ** Note : Utilization of SMS slag & BF slag has reached to 96% & 51 % in Nov 2007.

2.   Blast Furnace Slag
     Slag generation rates at Indian Steel Plants are comparatively higher than that of
developed countries, mainly due to inherent adverse quality of raw materials like high
ash in coal, high alumina and silica in iron ore ,etc .
     Efforts are made at BSL to reduce coke ash % by judicial blending of different
indigenous and imported coals and increased use of washed low alumina Iron Ore in
Sinter Plant and in Blast Furnaces, so as to reduce the Metallurgical Slags from the
process units.
      Coke rate also reduced by introducing Coal Dust Injection (CDI) and Coal Tar
Injection (CTI) system in BF which not only reduces specific energy consumption but
also reduces BF slag arising and also reduces environmental pollution in coke ovens
by reducing the coke making requirement for the given hot metal production. BSL has
Solutions to Wastes in Mining, Iron & Steel Industry                               [3.1 / 3 ]


CDI installed in BF 4 & 5 and CTI in BF 1 . Rest of the Furnaces will be fitted with
CDI in phased manner . This will also help to reduce BF slag arisings, appreciably in
the coming years.
      BSL has on site “Cast House Slag Granulation Plant “(CHSGP) in BF 4 & 5. BSL
is also having Offsite Slag Granulation Plant for granulating BF slag from BF 1, 2 & 3.
CHSGP will be installed in BF 1, 2 & 3 in phased manner, which will help in increasing
BF slag utilisation .
     At present the Granulated BF slag is sold to cement industry which produces
Portland slag cement (PSC). PSC is obtained by mixing Portland Cement Clinker,
gypsum and granulated slag in suitable proportions and grinding the mixture to get a
through and intimate mix between the constituents .
      It may also be manufactured by separately grinding portland cement clinker,
gypsum and granulated slag and then mixing them intimately . The resultant product is
a cement which has physical properties similar to those of ordinary portland cement . In
addition, it has low heat of hydration and is relatively more resistant to soils and water
containing excessive amounts of sulphates of alkalied metals, alumina and iron, as well
as to acidic waters, and can, therefore, be used for marine works with advantage . Mass
concrete works like large foundations, dams, port-and-harbor structures such as jetties,
break-waters, warfs; floating structures, sewerage and underground structures, pipe
lines and mines, also can be built using slag cement. It is also suitable for shore
protection works such as blocks, tetrapods, machine foundations, piling, caissons, piers,
wells, effluent and sewerage treatment plants, buildings, industrial structures, cooling
towers, silos and storage structures.
     Slag being available in Eastern India, Slag cement is quite popular in Eastern India
and many important structures like Second Hoogly Bridge, Underground Metro system
at Calcutta, etc. have used Slag cement.
     At BSL presently about 51% BF slag is granulated and sold to near by cement
industries. However cement industries in and around Bokaro area are very few, leading
to stock piling up of granulated BF slag happens, particularly since the cement
industries prefer dry flyash for making blended cement, to cut the cost of grinding of
Granulated BF slag. Thus there is a need to look for other alternative routes for
increasing BF slag utilization at BSL. Production of Ground Granulated BF slag
(GGBFS) and Air cooled BF slag aggregates for construction industry are the
promising avenues for enhancing the BF slag utilization at BSL.
Solutions to Wastes in Mining, Iron & Steel Industry                              [3.1 / 4 ]


3.    Ground Granulated Blast Furnace Slag
       With the advancement of technology and research in the field of concrete and slag
utilisation, a change came, and in year 2000 the BIS permitted the use of flyash and
Ground Granulated Blast Furnace Slag (GGBFS), as mineral admixture from the
consideration of “Durability criterion” (IS 456-2000).
     In the United States, the production and marketing of ground granulated blast
furnace slag (GGBFS) has seen extraordinary growth since its introduction in 1982.
Used as a partial replacement for portland cement, this byproduct of the steel industry
can significantly improve the durability of ordinary portland cement concrete and, at the
same time, have a positive impact on the environment. GGBFS is produced and used
widely in advanced countries like USA, Japan, Australia, Europe, UK , etc .

3.1 Environmental and Energy Conservation Aspects of GGBFS:
     The use of GGBFS as a partial Portland cement replacement takes advantage of
the energy invested in the slag making process and its corresponding benefits with
respect to the enhanced cementitious properties of the slag. Grinding slag for cement
replacement requires only about 25 percent of the energy needed to manufacture
Portland cement. Investigations show that one tonne of normal Portland cement
production discharges about 0.9 tonne of CO2 into the atmosphere, which is the major
green house gas. GGBFS typically replaces 35% to 65% portland cement in concrete.
Thus, a 50% replacement of each ton of portland cement would result in a reduction of
CO2.
               Typical CO2 Emissions for Portland Cement and GGBS Production.
                            (Figures in kg per tonne of output)
Solutions to Wastes in Mining, Iron & Steel Industry                               [3.1 / 5 ]


     On one hand, utilization of slag in cement / concrete conserves the energy,
minimizes the CO2, emission problem to the extent of its proportion in cement /
concrete, on the other hand, it reduces the accumulation of slag.
      GGBFS is a 100% recycled material, using significantly less energy at reduced
levels of CO2 emissions during production as compared to portland cement. Because of
this environmental posture, GGBFS is included in the list of recommended materials in
the National Institute of Standards and Technology study entitled Building for
Environmental and Economic Sustainability. GGBFS also has been recommended by
the U.S. Green Building Council's program called Leadership in Energy and
Environmental Design.
     The US - EPA recognizes the environmental and energy-saving values of GGBFS
by favoring its procurement and use in federally funded projects (EPA 40 CFR Part
247).
     Government should encourages everyone Steel Industry , ready-mix companies,
builders, contractors, engineers, and architects) to use GGBFS, thus producing better
concrete as well as saving energy and reducing the CO2 emissions in the environment.

3.2 CONSTRUCTION PROCEDURES FOR “GGBFS”

     Material Handling and Storage:
     GGBFS (or cement containing GGBFS) is handled and stored like conventional
Portland cement.

    Mixing, Placing, and Compacting:
     The same equipment and procedures used for conventional Portland cement
concrete may be used to batch, mix, transport, place, and finish concrete containing
GGBFS.

     Curing:
     The slower strength development of concrete containing GGBFS may require that
the moisture be retained in the concrete for a longer period of time than what is normally
required for conventional concrete. Scheduling of pavement construction should allow
adequate time for the specified strength gain prior to the placement of traffic loads, the
onset of freeze-thaw cycles, and the application of deicing salts.

    Quality Control:
     The same quality control procedures used for conventional Portland cement
concrete can be used for concrete containing GGBFS
Solutions to Wastes in Mining, Iron & Steel Industry                             [3.1 / 6 ]


4.   Steel Melting Shop (SMS) Slag
     In the field of SMS slag utilization, Bokaro Steel has done a pioneer job . BSL is
processing the SMS Slag in various fractions such as 0-5 mm , 5-10 mm, 10-20 mm
10-40 mm, 40-45 mm and 10-100 mm for various consumers. 0-5 mm slag is being
charged into Sinter Plant replacing equal amount of flux . Similarly 10-40 mm size are
being used in SMS and BF.
     The entire roads of Plant and Township are being repaired by 5-10 mm and 10-
40 mm size LD slag . BSL is having around 400 Kms of Railway Track for which 20-65
mm size LD slag is being spread replacing conventional stone ballast . BSL has not
purchased any stone ballast for maintaining its railway tracks in past few years
     BSL also supplying processed LD slag to IISCO Steel Plant, Burnpur which is
being charged in Blast Furnace.
     With the above mentioned recycling efforts, around 96% of LD slag is being
recycled / consumed within BSL which is highest among Indian Steel Plants.

6.   Conclusion
     With growing shortages of energy and materials, waste is now seen as a potential
resource. Environmental legislation and regulations and the economics of disposal are
directing the steel industry to look for ways of minimising the generation of wastes and
maximise recycling of collected wastes.
      Environmental Friendly Slag Cement ( made using BF Granulated slag and Steel
Making Slag ), Ground Granulated BF Slag (GGBFS) for using in Construction Industry
should be preferably promoted in India by necessary economic incentives and
legislative mechanism by MoEF in line with US EPA’s scheme and should be
enforced by Administrative Set up in India.
     Government should encourage everyone; Steel Industry , ready-mix concrete
companies, builders, contractors, engineers, and architects, etc, to use GGBFS, thus
producing better concrete as well as saving energy and reducing the CO2 emissions in
the environment. Directions to the concerned in Central Govt and in State Govts.
Agenicies like CPWD, PWD, NHAI, Railways , etc, to specify the use of Slag Cement
/ GGBFS in construction activities , will go a long way in meeting the utilization
targets of metallurgical slags from Integrated Steel Plants in India.

About the Authors
    Shri R.P. Singh, DGM, ECD, BSL.
      Shgri R.G. Segaran, Sr. Manager, ECD, BSL.
Solutions to Wastes in Mining, Iron & Steel Industry                           [3.1 / 7 ]


                                                                           Annexure-1


                 CHEMICAL COMPOSITION OF STEEL PLANT WASTES

                        PARAMETERS                     BF Slag   BF Slag

               SILICA                                   32.89     14.70

               ALUMINA                                  13.54     3.25

               OXIDE OF IRON                            21.40     22.20

               FeO                                      1.28      12.71

               LIME                                     25.16     36.15

               MgO                                      0.81      1.50

               LOI                                      0.60      4.21
Solutions to Wastes in Mining, Iron & Steel Industry                              (3.2 / 1)


                       MANAGEMENT OF SPLINTERS IN SMS

                                   S. Nanda, AGM (M), SMS-II
                                 D. Mohapatra, AGM (M), SMS-II
                                  Md. Islamuddin, DGM, Design



1.    Introduction
      Prevailing conditions affecting splinter (dust) generation

     Like most of the BASIC oxygen furnace shops operating in India, SMS II
department of Rourkela Steel Plant has also adopted the conventional way of making
steel that is desiliconisation, dephosphorization, decarbonization, and some
desulphurization is done upto the removable levels of the individual constituents in the
converter alone.
     Hence, generation of total dust is affected inside the converter only. As the hot
metal received from blast furnace normally contains silicon, phosphorus, and sulphur on
the higher side as well as manganese in small amounts, available lime of largely
compromised quality is used in higher quantities. Other constraints of converter
operation like lining protection with shortage of scrap etc. have imposed the adoption of
the use of iron ore and dolomite in optimum quantities. Briefly, we make steel in the
condition of slag in higher viscosity and the liquid metal with lower surface tension. We
also blow with a six-nozzle lance for improving the process of steel making. All these
factors facilitated the process of dust making in higher quantities. That is why against
the normal expectation of 3.5 to 4 tons of dust generation per blow, all our previous
assessments have shown a generation level in excess of 4.5 tons in slurry form only i.e.
excluding higher size grits.

2.  Dust Management
     In RSP, a Gas Cleaning Plant designed and commissioned by DAVY MCKEE
LTD. UK manages dust. It is a modified form of OG(Off Gas/ Oxygen gas) process
developed in Japan in 1975. As usual, it has two functional sections:
         Cooling section.
         Cleaning section

      Cooling section is an absolutely necessary and problematic section in all BOF gas
cleaning plants just to facilitate safe use of water as the cleaning medium owing to the
following parameters:
Solutions to Wastes in Mining, Iron & Steel Industry                                (3.2 / 2)


     1. Wet scrubbing system is suitable for BOF gases as no strong acid forming
        gases are generated during steel making. Hence, rapid corrosion does not take
        place due to use of water for scrubbing.
     2. Only the venturi type wet scrubbers have the capability and reliability to perform
        in severe fluctuations of dust quantity and size. The size distribution varies from
        0.008 µm to 250. µm under normal conditions and upto 500 µm or even beyond
        under abnormal conditions, but about 60% dust by mass remains in 1 to 60
        microns range by the time it reaches the cleaning section.
     3. Water cannot be sprayed to gases directly when gases are at temperatures far
        beyond 800 °C as water in steam phase at 800 °C (water gas) may dissociate
        forming explosive hydrogen. Thus, gases have to be cooled from about 1700 °C
        at converter mouth to about 900 °C.

     4. The cooling section also serves the most important function of dust preparation
        and separation. It flocculates most of the fine dust to bigger agglomerates and
        returns back many bigger/heavier particles to converter.
               Right from the converter vessel mouth, gasses along with all splinters are
         guided through the skirt to cooling hood. Dust is mechanically entrained
         upwards along with the gases. Turbulences inside the hood are avoided by
         design upto the cleaning section so that flocculation is facilitated.
         In RSP, the cooling section has some special features uncommon to many
              others.
         1. System has been designed for atleast 50% more gas load than normally
              working.
         2. Much care has been taken in all the equipments to minimize erosion and
              ensure smooth flow of fluids.
         3. Pressure drop in fluid flow has been ensured to be bare minimum with
              adequate compensation.
         4. All the susceptible pockets have been adequately taken care of against
              locked in hazardous gases.

3.   Cleaning Section
     In the cleaning section, two stages cleaning has been provided. The first stage
cleaning starts with a quencher which cools the gases and dust from about 900 °C to
about 75 °C. The quencher is designed to trap all the heavier particles and some of the
smaller particles. The quencher is followed by the primary venturi scrubber and the
primary separating elbow where contaminated water is collected and drained off to the
flume.
     The gases with residual fine particles are then guided to the secondary cleaning
stage, which is provided with a high energy venturi scrubber. The secondary scrubber is
supplied with clarified water from wastewater treatment plant, which gets partially
Solutions to Wastes in Mining, Iron & Steel Industry                               (3.2 / 3)


contaminated after cleaning. This partially contaminated water is then separated from
the gas stream at the secondary separating elbow just below the secondary scrubber
venturi and pumped to quencher for final use before sending to waste water treatment
plant.
     The wastewater contains dust particles almost of all sizes starting from submicron
to about 500 microns. Almost 99.5% of the dust generated in the converter basin are
captured by the inside gas cleaning plant and the flare stack normally exhausts some
dust in the invisible or mild color sizes.

4.    Sludge/Slurry Management
      The wastewater treatment plant (WWTP) receives highly contaminated water by
the flume (launder). The flume discharges water to a screw classifier where a few
seconds settling time is available. Almost all the bigger particles and granules settle on
the floor and swept by screw classifier. These granular dusts is then conveyed and
discharged for onward utilization in sintering plants.
     The slurry/contaminated water is then subjected to chemical treatment in a flash
mixer compartment and discharged to thickener/clarifier for sludge settling. The
contaminants normally settle completely in the thickener. The outlet condition of the
water from the thickener is
        P.H – 12.5 (11.5 to 12.8)
        Total Harness – 300 to 1000
        Total suspended solids – 25 to 35 milligram/litre
       In the original system, sludge was being drawn from the center of the thickener
by underflow pumps to sludge holding tanks. From sludge holding tanks, it was pumped
at the desired rate to drum filters for final cake formation and disposal.
     As usual the low reliable drum filters continued to pose problems. They were rarely
able to cope up with slurry generation rate and thickener level used to swell up. The
cakes were never very dry or suitable for transportation. Spillages were rampant in the
area. It used to flow along with water to drains during rainfall or otherwise. The ground
remained muddy all around and vehicular movements on dried or wet sludge were
contaminating a larger ground area and even the air above it. Higher rate of production
only worsened the matters.
     In order to save the environment from this menace, the slurry-handling project was
taken up and it was decided to transfer the slurry to pits on the ground level. Three pits
were made with earthen embankments and facilities for dry slurry disposal was also
Solutions to Wastes in Mining, Iron & Steel Industry                              (3.2 / 4)


incorporated so that while one is in operation, the other two can be left for drying/
disposal as per requirement.
      The pits have been constructed at an average distance of 1200 meters from
wastewater treatment plants. The ground was leveled and earthen embankments of 2.6
meter height were constructed. NB125 size slurry handling pipes (2 lengths) have been
laid for discharging slurry at the rate of 75 m3/hour.
     Originally, the scheme was to draw slurry from thickeners to sludge holding tanks
from where it was to be pumped to the pits. The scheme was found to be facing some
capacity mismatch problems for pumping. Higher temperature and fluctuating density of
the sludge in the sludge holding tanks led to operational problems for the pumps. It was
decided to try direct pumping from under the thickeners so that slurry density remains
quite low and higher positive suction is ensured irrespective of temperature. The trial
was successful and consistent behavior of the pumps was observed.
     The project has been running successfully since March 2006 and that is the major
reason why we have been able to cope up with high level of production. Now the
system is running for only three hours every shift and still able to manage the whole
dust load.

5.    Observations
      Some of the observations in the system are noteworthy.
      1.    After about two hours of operation in every shift, the slurry density at
            discharge point is very low indicated by a drop in discharge line pressure as
            well as color of the slurry.
      2.    Sludge buildup in the thickener has never taken place.
      3.    The settled sludge made a gradient of almost 1 in 125 in the pit whereby the
            sludge touched the discharge pipe while covering half the length of the pit
            only. It has necessitated multiple feed points per pit for full utilization.
      4.    Water has never overflowed on the weir provided on the embankment
            opposite to the feeding point. It has always passed through the embankments
            to surroundings apart from normal evaporation. Retained water level is
            always quite low.
      5.    Permanent water accumulation has occurred in the unused pit which were
            previously drier. Minor leakage has also been observed on the base of one
            side embankment. The water quality of the leakage is surprisingly very good
            (compared to water after sedimentation).
Solutions to Wastes in Mining, Iron & Steel Industry                               (3.2 / 5)


      6.    PH – very near to 10
      7.    TH< 10
      8.    Turbidity - .5 NTU max
      9.    Some snakes and small insects have been found swimming in this water.
      10. It may be one consolation that even the ground water may not be getting
          polluted owing to this project.
      11. Pit no. 3 which is much deeper compared to other pits has become a lake
          with clear water of the above quality. We may think of using this water for
          suitable purposes.

6.    Conclusion
      Seepages through embankments or ground may require some changes in layout
etc to ensure drying of the sludge in pits when nearby pit is in operation.
     Use of dried BOF sludge is normally a challenge for conventional sintering plants.
Many steel plants prefer to make briquettes by using PVC, polyethylene or
polypropylene as binders and use them in blast furnaces. Process of direct use in BOF
converters after briquetting is also available. Portland cement has never been
successful in binding the sludge for making bricks and the last use as land filler is
neither economical nor devoid of other controversies. In this situation, many steel plants
have adopted processes, which have reduced generation of total dust by about 50%.
We may have to resort to some similar ways in the future.
Solutions to Wastes in Mining, Iron & Steel Industry                                 [3.3 / 1 ]


             EFFECTIVE SOLID WASTE MANAGEMENT IN
      IRON & STEEL INDUSTRY WITH A SPECIAL REFERENCE TO
                     ROURKELA STEEL PLANT

                    *Dr. B N DAS, General Manager (Env. Management),
                      ** V V R MURTY, Sr. Mgr. (Env. Engg. Department)
                               Sail, Rourkela Steel Plant, Rourkela



                                               Synopsis

      The quantity of waste generation and its quality are the indicators of Steel Plant’s
operational efficiency and quality of input raw materials. Waste generation is a threat to
environment protection and sustainable development. Basically two types are wastes
viz., ferruginous wastes (iron bearing) and non ferruginous wastes are generated from
different processes during the Iron & Steel making. The ferruginous wastes can be
gainfully utilized by proper recycling, back to process, for steel making where as proper
method of usage is to be identified for the non ferruginous wastes for maximization of
their utilisation . The principle of 4R (Reduce, Reuse, Recover & Reuse) is adopted as
baseline for Solid Waste Management in Rourkela Steel Plant . Disposal of wastes
confirming to statutory requirements is a last resort in effective solid waste
management.
      No one is waste in this nature. It is the responsibility of the technocrats to identify
the various alternate uses of the wastes to make them as by products. Recovery,
recycling and reuse of wastes in steel making not only earn revenue in terms of saving
of basic raw materials replaced but also conserves natural minerals from depletion.
Recycling and reuse of wastes have their own limitations hence disposal of wastes has
become inevitable. Disposal of wastes on land is a big threat to environment. Use of
different slags as pavement material, railway ballast and use of fly ash in cement
manufacturing are already established by research organisations. Government’s
support and stringent directives are the need of the hour to support steel industry in
effective management of wastes .

1.   Introduction
     In an integrated steel plant, 5 tonnes of input raw materials in the form of Iron Ore,
Coal, Fluxes, Ferro alloys & Refractory are required for making 1 tonne of Crude Steel .
In the process of steel making around 3.5 tonnes of wastes like slags, dusts, sludges,
Solutions to Wastes in Mining, Iron & Steel Industry                                          [3.3 / 2 ]


fly ash, mill scales etc., are generated. The general flow of materials in iron and steel
making is given in Fig.(1) . The main reasons for high quantity of waste generation are
poor quality of raw materials i.e., Iron ore and Coal. High alumina content in Iron ore
and poor coke quality lead to high coke rate in hot metal production resulting in high
quantities of Blast Furnace slag generation. High ash content in boiler coal results in
high fly ash generation in captive power plants.



                                          ORE BEDDING &                         OXYGEN
                  COKE
                                         BLENDING PLANT                      PLANTS (TOP#1
                  OVENS
                                             (OBBP)                               & 2)

                              SINTER                             SINTER
                             PLANT#1                            PLANT#2



                                         BLAST FURNACES
                   PIG
                 CASTING
                 MACHINE
                                          STEEL MELTING
                                          SHOPS (# 1 & 2)



                              PLATE                            HOT STRIP
                               MILL                              MILL




       SWPP                   ERWPP                               CRM                        SSM



                                     Fig (1) Flow of materials in Steel Making


     The comprehensive qualitative analysis of different solid wastes help in identifying
the areas where the wastes can be recycled back and gainfully utilised. The wastes
coming out from steel making can be broadly divided into two categories i.e.,
Ferruginous wastes and Non Ferruginous wastes. The iron bearing ferruginous wastes
are generated from steel making viz., mill scale, flue dust, sludges from Gas cleaning
plants of Blast Furnaces and Steel Melting Shops, Blast furnace slag and SMS slag.
These ferruginous wastes can be recycled after suitable processing. The non
ferruginous wastes are lime fines, broken refractory bricks, broken fire clay bricks,
acetylene plant sludge etc. These are reused for various purposes viz., lime fines for
Solutions to Wastes in Mining, Iron & Steel Industry                               [3.3 / 3 ]


neutralisation of acidic water, broken refractory bricks for pavement making, and
acetylene plant sludge for white washing.

2.    Ferruginous Wastes
      The iron bearing wastes, generated at different stages of steel making are suitable
for recycling back to steel making process and reusing in place of raw materials after
suitable processing. The recycling of ferruginous wastes back to process is not only
replacing iron ore but also other raw materials like Iron Ore (Fines), Lime stone and
Coke breeze (coal) . The different types of ferruginous wastes generated at different
stages of steel making in Rourkela Steel Plant, their quality and quantity of generation is
given in Table-1.

2.1 Mill Scale
      The mill scale which is nothing but oxides of iron, is generated when the hot slab,
plates, coils are cleaned with water during rolling. Mill Scale is generated from Steel
Melting Shops, Hot Rolling Mills and Cold Rolling Mills. Mill scale is generated at a rate
of 2% of steel rolled in rolling mills . The mill scale coming along with wastewater is
separated in wastewater treatment plants. As mill scale is nothing but iron oxides having
Fe upto 98.5%, its recycling back to Ore bedding and blending plant is replacing Iron
ore (fines) to an extent of 115% . All the mill scales generated in Rourkela Steel Plant
are recycled back 100% and gainfully utilised.

2.2 Blast Furnace Flue Dust
     The dust coming along with Blast furnace gas is first separated in dry form at Dust
Catchers, is called Blast Furnace Flue Dust . The BFc. Flue dust is generated at a rate
of 50 gms per one Tonne of Hot Metal production. The chemical composition of BFc.
flue dust shows that these wastes can replace Iron Ore (Fines) and Coke when it is
recycled back for making base mix . Recycling of 1 T of Blast furnace flue dust is
replacing 0.63 T of fresh Iron Ore(Fines) and 0.37 Tonnes of Coke . All the Blast
Furnace Flue Dusts are recycled back and gainfully utilised in Rourkela Steel Plant for
making base mix.

2.3 BFc sludge/SMS Sludge
     The micro fine particles separated from Blast Furnace Gas and BOF gas at Gas
Cleaning Plants in the form of sludge is called BFc sludge/SMS sludge. The rate of
generation of sludge is 0.018 T of Tonne of crude steel . The composition of sludges
shows that, they can replace Iron Ore (fines) and Lime Stone, when the sludges are
recycled back for making base mix in Ore Bedding Blending Plant. One tonne of sludge
replace 0.62 T of Iron Ore(fines) and 0.38 T of lime stone, when it is recycled back for
making base mix for sinter making.
Solutions to Wastes in Mining, Iron & Steel Industry                              [3.3 / 4 ]


      Handling and transportation of sludges are posing environmental problems. The
spillages on roads during transportation, is the main problem with recycling of Sludges .
Recycling of these sludges throughout the year is not possible, particularly during rainy
season, as the sludges become wet and cause jamming in unloading facilities . In
Rourkela Steel Plant, the BF sludges are mixed with BFc flue dust and transported back
to OBBP for making basemix. In Rourkela Steel Plant, the BFc sludges are utilized
100%. SMS sludge, in the form of slurry, generated from Waste Water Treatment Plant
is transported to sludge ponds in pipe lines for drying. ponds have been constructed for
storing and drying of SMS sludges. One pit is always in operation, another pit is under
drying and the third one will be under reclamation. The dried sludge is excavated and
recycled back to OBBP for making base mix .

2.4 SMS Slag
      The impurities present in raw materials and hot metal come out as slag during
crude steel production in Basic Oxigen Furnace. The rate of slag generation in SMS is
0.18 T per one tonne of crude steel production. The SMS slags are very rich in calcium
content to an extent of 45-50% (as CaO), iron content to an extent of 20-22% (as FeO) .
The calcium content in SMS slag can replace addition of lime stone when it is added for
base mix making . Recycling of 1 T of SMS Slag replaces 1 T of Blast furnace grade
limestone . It is also established by studies conducted by Central Road Research
Institute (CRRI) that SMS slags can be gainfully utilised for road making as pavement
materials and concreting . Research works carried out by RDSO, of Indian Railways
established that SMS slag (40-60 mm) can be used gainfully as rail ballast . The SMS
slags can be utilised for various purposes only after proper processing. After proper
crushing and segregation, the SMS slags of size <5mm can be used for base mix
preparation for sinter making as a substitute for lime stone. The SMS slags of size 5-20
mm can be used for concreting purposes in pavement making. SMS slags of size
ranging from 20-40 mm can be used directly in Blast furnaces in place of Blast furnace
grade Lime stone . The sizes above 40 mm & <60 mm can be used as rail ballast.
     All the railway tracks inside Rourkela Steel Plant (190 Kms) are laid on SMS slag
ballast. SMS slag is used for making all roads inside the Steel Plant and in Townships in
Rourkela. Rourkela Steel Plant is gainfully utilising SMS slags upto an extent of 45-
50% only. The high volumes of SMS slag generation is leading to its disposal on
ground.

2.5 Blast Furnace Slag
     In the process of making Hot metal in Blast Furnaces, the impurities present in raw
materials are forming into slag and coming out along with hot metal. The slag
generation rate is 400 kg/tonne of hot metal produced . It is established that Blast
furnace slag is a good raw material for making slag cement only after proper
Solutions to Wastes in Mining, Iron & Steel Industry                                [3.3 / 5 ]


granulation. Granulation is 100% only if the slag is granulated immediately after
production; otherwise slag gets solidified and will not be fit for granulation. The un-
granulated slags are air cooled and disposed on ground. Installation of in-house slag
granulation facilities in Blast furnaces will solve the problem of slag solidification and
facilitate 100% slag granulation. Rourkela Steel Plant is having inhouse slag granulation
facilities at 2 blast furnaces, BFc#1 & 4. A separate slag glanulation plant is installed to
take care the slag coming out from BFc.#2 & 3. The present rate of overall slag
granulation is 90-92% and is gainfully utilized 100% for cement making. The use of
granulated slag is replacing lime stone in cement making. Utilisation of BFc. Granulated
slag is not only saving the precious lime stone but also reducing the green house gas
emissions on account of lime stone usage. The use of BFc granulated in place of lime
stone in cement making is reducing the green house gas emissions to an extent of
936.4 kg of CO2 / Tonne of BFc slag utilized.

3.   Non Ferruginous Wastes
      In Iron & Steel making, different non iron bearing wastes are generated from
various operation like, refractory lining in converters & furnaces, making of acetylene,
calcinaion of lime and dolomite & boiler coal for captive power generation. These are
called Non Ferruginous Wastes. They are;

      •     Used Refractory bricks
      •     Used fire clay bricks
      •     Acetylene sludge
      •     Lime fines
      •     Dolomite fines
      •     Fly ash

      The quantity of generation and their utilisation are given in Table-1.

3.1 Used Refractory Bricks
    60000 T of refractory bricks are used every year in RSP. Out of which 1500 T of
used refractory bricks are salvaged for reuse and rest consisting mainly magnesite and
chrome-magnesite bricks are being sold . The rejected refractory bricks are used for
pavement making in RSP.

3.2 Acetylene Sludge
     Rourkela Steel Plant has two number of Acetylene plants for production of
acetylene gas from Calcium Carbide. About 1700 T of acetylene sludge is generated
from these plants. This sludge is highly alkaline in nature and can be used for
Solutions to Wastes in Mining, Iron & Steel Industry                                  [3.3 / 6 ]


neutralisation purposes. This sludge can also be used for white washing purpose.
Presently the acetylene sludge is being sold out.

3.3 Dolomite & Lime Fines
      In Calcining Plant#2 & LDBP of Rourkela Steel Plant, lot of dolomite & lime fines
are generated during calcination of dolomite and lime stone. These fines are mostly
arising from material handling operations, screening and are captured in various dust
extraction systems in the plant. The CaO content of these lime fines is ranging from 85-
87% and can be gainfully utilised for neutralisation purposes as well as for white
washing. These lime fines are also gainfully utilised as trimming addition in Sinter Plant.
The lime fines are also being used for neutralisation purposes in water treatment plants
for township, neutralisation units of Cold Rolling Mill . All the fines are gainfully utilized
to 100% in Rourkela Steel Plant.

3.4 Fly Ash
      RSP is having a coal based Captive Power Plant. The ash generated during the
burning of coal, called fly ash is disposed off by dry & wet methods. The fly ash
generation is 36000 T/month . Presently most of the fly ash is disposed off in wet
condition in Ash ponds. The disposed fly ash is presently used only for raising dyke
height of ash ponds . Dry fly ash is also disposed to cement manufactures from MP
boiler#3 presently. Arrangements are being made for direct disposal of dry fly ash from
captive power plant HP boilers of RSP.

4.   Plan & Prospects Of Solid Waste Management
     Rourkela Steel Plant has started effective management of Solid Wastes in the year
1998. The solid waste utilisation has increased form a level of 55.3 % in the year 1999-
00 to a level of 73% in the year 2006-07. The utilisation of solid wastes is not only
earning revenue to the company but also reducing the consumption of precious natural
resources. It is planned to increase overall utilisation of solid wastes to 80% in the year
2007-08. It is planned to further increase the solid waste utilization in RSP by increasing
the recycling of SMS slag fines back to OBBP for base mix preparation. Consistent
operation of in-house slag granulation facilities at BFc#1 & 4, strengthening of Slag
Granulation Plant‘s efficiency will further augment the Blast furnace slag granulation and
increase the overall utilisation of solid wastes in the coming years.

5.   Conclusion
     The management of Solid wastes from steel making is a major environmental
issue to be tackled properly as the quantities are very large . Consistent efforts are
required to maximize the utilisation of these solid wastes. Whatever unuilised wastes
are left behind are to be properly disposed on the ground in a systematic way. The
Solutions to Wastes in Mining, Iron & Steel Industry                                           [3.3 / 7 ]


dumping sites are also developed systematically. Devising means to reduce, recycle
recover and reuse of solid wastes can only solve the problem. While substantial
progress has been made during last few years these areas, yet much more remains to
be done.


                                                    Table-1

                     Solid Wastes Generation & Utilisation in Rourkela Steel Plant

                                        QUANTITY OF
                       SOURCE OF                                                         UTILISATION
         SOLID                          GENERATION
 SN                     GENERA-                                    QUALITY                   (%)
         WASTE                               (T)
                         TION                                                              2006-07
                                          (2006-07)
                                                        Fe= 46-52-%; CaO= 22-30%;
                           Blast
  1.     BFc slag                         827575        MgO= 4-10%; MnO= 2-6% &            90.75 %
                         Furnaces
                                                        SiO2 = 26-31%
                        Steel Melting                   Feo= 18-21%; Sio2= 16-18%;
  2.     SMS slag                         366933                                           47.92%
                           Shop                         CaO= 47-53%
                                                        C=16.6-33.4%;    LOI=    19.4-
         Blast
                        Blast furnace                   43.6%; Fe= 30-40.5%; SiO2 =
  3.     furnace                           14883                                            100 %
                        dust catcher                    7.4-11.6%;   CaO=     2.3-4.6;
         flue dust
                                                        MgO= 0.5-1.2%
                       Waste Water                      C= 2.13%, Fe= 51.8% ; MgO=
         SMS
  4.                     treatment         35919        2.0; S= 0.21%; SiO2= 2.1;          0.39 %
         sludge
                       plant of SMS                     CaO= 12.8; LOI = 6.7%
                        Rolling Mills
                        waste water
  5.     Mill Scale                        37836        Mixture of iron oxides              100%
                         treatment
                           plants
         Acetylen        Acetylene                      SiO2=4-6%;  Al2O3=       1-3%
  6.                                       2244                                             100%
         e Sludge          plants                       CaO= 60-70%
         Calcined       Calcination
                                                        Cao=70-80%;      MgO=3.5%;
  7.     lime            Plant#2 &         32231                                            100%
                                                        SiO2=1.7%; Al2O3= 3.5%
         Fines             LDBP
         Used          From relining
         refractory    of converters,                   Basically CaO, Al2O3 and
  8.                                       2946                                             100%
         / fire clay   furnaces and                     traces of Fe2O3 and MgO
         bricks            ovens
 Total                   Steel Plant      1321722                                           77 %
Solutions to Wastes in Mining, Iron & Steel Industry                                   [3.4 / 1 ]


 RE-CYCLING OF WASTE FROM IRON STEEL INDUSTRY FOR SAFER
          ENVIRONMENT AND BETTER PRODUCTIVITY
                   Mr. B. Sankar, Dy.Manager - Mr. R.K. Dutta, Asst. Manager -
                          Mr. P.K. Pani, Production Superintendent
                                    OCL Iron & Steel Ltd.


Introduction
       With the revival of Industrial scenario all over the world, the Iron steel plants are
growing anything like mushroom, with the emergence of no of plants also posed a big
challenge among the manufacturer to recycle the waste coming out of the process. It is
not only the disposal of the waste but it has a necessity also to keep the environment
clean as well as increase the productivity. The rapid growth along with their
technological limitations a severe problem is being faced by the industries in the area of
environmental pollution leading to ecological imbalance for the society. The problems
become much grimmer as they are placed in a situation of stiff competition with
enormous quantity of generated waste and their handling, disposal, elimination or re-
utilization. As day-by-day the Govt. of India become more conscious about the
environment we all have to think seriously about the above matter. With the growing
price of steel the raw materials cost is also going high so by recycling of the waste will
help in bringing the production cost down.
      Steel industry has been transformed into a dynamic industry within many
fundamental ways the steel is produced, fast to adopt new technology and at the same
time these changes have made new challenges to be solved. Even though steel makers
traditionally had recycled a good amount of by-products they produce .A new process a
better social awareness and more restrictive legislation have generated new ideas and
new technologies for better re-using of all of them. Most of the times, compliance with
environmental regulations has been a burden for the steel makers, adding extra cost to
steel products .It seems that only economic solutions to the environmental problems are
when the by-products are considered as raw material for some other process, thus
obtaining an economic value and not been considered as waste product.
      The most common and economical route for making steel with low initial
investment is Induction –caster route with own sponge iron plant and captive power
plant many of the mini steel plant have this set up .The major waste material generated
in this set up are
Sponge Iron plant (i) Iron ore fines (ii) coal fines (iii) bag filter dust
                         (iv) Waste flue gas (v) Accretion material (vi) Sponge iron Fines
Solutions to Wastes in Mining, Iron & Steel Industry                              [3.4 / 2 ]


                         (vii) Char
Power plant            (i) Fly Ash (ii) Esp. dust
Steel Plant            (i) Slag (ii) Mill Scale

Waste Mangement
     The disposal of waste generated from the industrial processes is the major
concern Reduce, reuse and recycle philosophy and efficient waste management has
to be prompted.
     The material generated in a process which is unused and rejected in that process
is considered as a waste.

Iron ore fines and Coal fines
      Iron ore and coal are the two major raw materials for the Iron & steel industry but
the process required certain size of raw material. There fore crushing and screening is
required. During crushing of iron ore lumps normally 30% fines (-3mm) are generated of
total lumps ore. From chemical analysis it has been seen that it contain >65% Fe (T).
Similarly in case of coal. The generation of coal fines is very high in dry season as
compare to the cosumption. These excess fines coal are required to be disposed off in
dry season.
     2 to 5 mm of the ore can be used in rotary kiln sponge iron process directly by
adjusting coal size and process parameters.
    0 to 2 mm ore fines can be used by pelletisation in other iron making process such
as BF-BOF route, Oxicup, gas based sponge iron process.

Bag filter dust
     High capacity bag filter are installed in dust emission area the dust generated from
bag filters are considered as waste .The dust generated from coal bag filters have the
proximate analysis report VM=2%, ASH=75%, FC=23% similarly the iron dust also
contain .65%Fe (T).
      It could be used in the AFBC of the power plant.
     It could also be used in the brick-manufacturing unit for construction job for which
they are using the top soil of the earth

     Waste flue gas
     In rotary Kiln sponge iron process exit gasses are called waste gas. These gases
contain high heat value. Chemical composition of this is as follows
Solutions to Wastes in Mining, Iron & Steel Industry                               [3.4 / 3 ]


      CO2 = 19%
      H2O = 17%
      O2 = 1%
      CO = 0.5%
      SO2 = 0.05%
      CH4 = 0.8%
      N2 = 61.65%
     The temperature of the flue gas can be utilized in power generation through waste
heat recovery boiler

      Accretion Material
      Accretion materials which we are getting out of the kiln are mainly comprised of:-
      Al2O3 + SiO2 = 70-78%, Fe2O3 = 20 – 28%, rest is TiO2, CaO, MgO, Fe (M).
        It can be used in the Oxicup furnace.
        It can also be used in the land filling in the mining areas
        It can also be thought of to extract the 30% hematite from the amount through
        the mineral beneficiation process.

    Sponge iron fines(-1mm)
    Sponge iron fines (-1mm) generated is approximately about 20%. Which are
normally creating several problems in melting.
      Sponge iron fines can be processed for production of electrolytic Iron powder of
Ultra high purity, high strength P/M parts, higher productivity and this process is Useful
for production of high and medium density PM parts and high quality welding
electrodes.

      Char
      Char generation in the rotary kiln is approximately 25%to 30%.
      Having proximate analysis report of:
      V.M = 1% to 2%.
      ASH = 68 %( Approx.)
      FC = 30% (Approx.)
Solutions to Wastes in Mining, Iron & Steel Industry                               [3.4 / 4 ]


      CV = 2000 Kcal/Kg
      Chemical analysis of char:
      LOI = 31.72
      SiO2 = 38.64
      Al2O3 = 17.12
      Fe2O3 = 10.67
      CaO = 1.13
      MgO = 0.15
      Na2O = 0.09
      K2O = 0.48
     Char can be utilized in AFBC for power generation. And its chemical composition
suggests it can well be used as a cement raw material replacing siliceous material
having potential heat value around 2000 Kcal/Kg, which can save some fuel during
burning in cement kiln also.

     Slag
     Slag is a by-product from the foundry process. The type of slag produced by a
foundry will depend on the Processes used. Common ferrous foundry slag includes:
      n cupola slag (air-cooled or water-quenched);
      n induction furnace slag;
      n electric arc furnace slag;
      n desulphurisation slag.


     The physical and chemical characteristics of slag make it ideal for re-use in a
range of applications. Its chemical Composition makes it suitable for use as a source of
various minerals. Physically, its mineral-like properties make it particularly suitable as
an aggregate replacement...

Use Of Iron & Steel Making Slag
      Reuse of iron & steel making slag largely depends on slag chemistry and the
methods used for it’s cooling. With increase in production of steel, production of slag
also increased significantly. So, several new areas have been explored for reuse of
slag. Slag has been used since ancient time for construction purposes.
Solutions to Wastes in Mining, Iron & Steel Industry                               [3.4 / 5 ]


       The use of slag increased significantly in asphalt blends for smooth road paving.
Air-cooled blast furnace slags are used for road construction after crushing and
screening. Water cooled blast furnace slag are widely used for cement making because
of its cementations properties which develops with lime and water.

Reuse of slag generated from foundry process
1.) Cupola slag: The air-cooled cupola slags are used in asphalt, ballast, bricks, mineral
wool, and road base construction. The water-cooled cupola slags are used in
blockmaking, bricks, mineral wools, soil modifier, and abrasives running surfaces.
2.) Induction furnace slag : Road base construction, abrasives.
3.) Electric arc furnace slag : Ballast, road base construction.
4.) Desulphurization slag : Soil modifier, slaked lime replacement, blast furnace slag,
and    Cement manufacture.

      Mill scale
      Mill scales are the oxides of iron produced during hot fabrication of the steel.
During continuous casting of near about 0.6 -0.7% of mill scale generated of the
finished steel billet.
      Mill scale having composition of
      Fe (T) = 70 %( Approx.) , Oxygen by weight 25%
      Other gangue material = 8%
      Sulphur = 0.1%
      VM = 4.5%
      The use of mill scale as an oxidizing agent results in improving the yield of process
but it needs thermal energy to dissociate it self and make oxygen available for refining
reaction.
      These materials can be utilized as oxidizing agent in the melting furnace, which
can remove phosphorus as P2O5 and reduce the carbon content in the molten bath also
this can be used in thermit welding process.

      Fly Ash
      Fly ash is generated in the AFBC boiler and it is about 70% of the charge into it
.Fly Ash is composed of: -
Solutions to Wastes in Mining, Iron & Steel Industry                                [3.4 / 6 ]


      Al2O3 = 20-25%
      Fe2O3 = 8-10%
      TiO2 = 1-1.5%
      CaO = 1-1.5%
      MgO = 1%(Approx.)
      SiO2 = 60-65%
      Na2O = 0.05%
      K2O = 0.5 -1%
    Fly ash can be used in the cement plant for making PPC.This fly ash can also be
used for bricks making for building construction

     ESP Dust
     The residual dust particle from flue gas exited from the kilns are collected by the
TR set of Electrostatic precipitator are receipted in the hopper. These dust particles are
termed as ESP dust. The ESP Dust generated could be used for brick manufacturing.
      It could also be used in the AFBC boilers as a potential fuel.

Modern Recycling technology

      Environment-friendly and Energy optimized technologies for
     Competitive iron and steel making
     As the production of steel is increasing, the generation of wastage is also going
high. Though, lots of work has been done in the area of recycling of waste generated
from the steel plant, further research work is still going on. Oxi-cup is a very good
process in which we can minimize the waste generation as low as to zero level.
     This process is based on self-reducing agglomerates containing iron oxide fines
and carbon in the form of brick. These bricks are made up ESP Dust, Skulls/ rubble,
     Iron ore fines, coal fines, Skulls, Processed sags, Mill scale sludge, Mill scale, Flue
Dust Esp. dust, Sponge iron fines, Acrietion materials, Bag filter dust. Which are
     Charged into a shaft type furnace called Oxi-cup for smelting to deliver sustainable
hot metal to EOF/BOF shop.
Solutions to Wastes in Mining, Iron & Steel Industry                                  [3.4 / 7 ]


      The advantages of this process: -
      (i)    Agglomerations of coal fines in a cold bond process.
      (ii)   Smelting and melting from one heat.
      (iii) Minimum lump coke consumption

Conclusion
     Steel production is one of the most important indicators and indices of economic
development of a country. Much belatedly the concern for ecological degradation has
cautioned the mindset of steel producers. The steel producers are gradually phasing out
the obsolete and energy intensive technology to efficient one.
     For its more survival and growth in this era of stiff competition and stiff hike in input
costs, the industry has no better option. By doing so benevolence to the society can
also be established since it not only gives wealth to the industry but conserving the
natural resources to a greater extent and hence maintaining the ecological balance and
health of the society at large. Let us have an oath to save the earth to provide us a
healthy; clean, and congenial society to live in by converting the waste in to a raw
material for recycling for better productivity, which is the right solution in the right time.
Business Opportunities in Waste Reuse in Iron & Steel Industry                     [4.1/ 1 ]


     AMERICAN EAF DUST RECYCLING THROUGH VITRIFICATION
  This Paper was presented to Iron & Steel Society Electric Arc Furnace Conference,
                           Dallas, Texas December 9,1996
                    Local Reps. In Asia: Zoom Developers P Ltd
                  Status Of Eaf Dust Recycling Through Vitrification
                                John H. Buddemeyer
          V.P. Engineering and Operations Inorganic Recycling Corporation
                          (Taken over by Pacific Sterling Inc.
                 Paper Printed with Permission from Pacific Sterling)


Introduction
     Inorganic Recycling Corporation (IRC) has developed and commercialized a
method for recycling EAF dust that is:
     - Environmentally sound
     - Inherently economical
     - Inherently reliable
     - Commercially proven

     IRC is the only dust handling system capable of offering a strong potential for
reduced fees over the next ten years, with product improvement and development,
rather than increased fees.
      Using silicate chemistry, IRC's process converts once environmentally hazardous
EAF dust into friendly commercial products of lasting value. Products are in the glass--
ceramic family of materials. (See Figure 1 and Figure 2) They are typically used as an
ingredient in the manufacture of many other commercial products. Examples are:
roofing granules, ceramic floor tile, abrasives and architectural applications.
     IRC supplies glass-ceramic products to users who require products with more
consistent or more customized properties than are available through naturally occurring
materials now used. EAF dust provides low cost feedstock materials which are of great
value in achieving desired product properties. Low feedstock costs enable IRC to sell
recycled products at highly competitive prices that remain predictable over the contract
period.
     An IRC recycling facility is normally located on a steel mill's site and accepts dust
directly from the bag house, thereby eliminating transportation costs and risks. In the
Business Opportunities in Waste Reuse in Iron & Steel Industry                    [4.1/ 2 ]


IRC process, dust is mixed with other raw materials, melted, then cooled and formed
into recycled products that meet customer specifications.


Arkansas Black Glass Specimen #1




    Fig. 1 400X magnification of current IRC product showing various crystal forms.




     Fig. 2 400X magnification of Annealed IRC product showing growth of crystals


     Once recycled, EAF dust looses the "liability trail" normally associated with
hazardous waste operations. Both Inorganic Recycling and the steel mill are thoroughly
and completely isolated from hazardous waste liability.

     IRC's recycling services are provided on a low risk, pay for services rendered,
basis. Dust is recycled in return for an agreed price for each ton recycled. Facility
design, installation and operation is at IRC's expense. No capital investment is required
by the steel mill.

Theoretical Basis For The IRe Product
      Technically, a glass is any solid material that does not have long-range order
(periodicity) in its atomic structure. A ceramic is any inorganic, nonmetallic material.
comprised of a single crystal or of many small crystals (polycrystalline). In practice,
glasses and ceramics are often interrelated. This is possible because the same material
composition can often be fabricated as a glass, a ceramic, or a combination of the two,
Business Opportunities in Waste Reuse in Iron & Steel Industry                        [4.1/ 3 ]


depending on the way the material is thermally treated. Glasses are, generally
speaking, super-cooled liquids of extremely high viscosity. When heated to a specific
temperature, glass becomes low enough in viscosity that the atoms cannot order
themselves sufficiently to become crystalline. However, if cooled slowly enough, they
can become ordered (crystalline), as shown schematically in Figure 3.
      The most common glasses, e.g., window glass, in use today are based on a
silicate structure (Si02), the same material used in many ceramics, e.g., dinnerware.
Silicon dioxide in pure form can make a very fine optical glass called fused silica;
unfortunately, the temperature required to form it is very high, restricting its use to areas
where a very low thermal expansion material of high optical quality is required. The
more common glasses use fluxing agents, like Na20 or K20, Figure 4, which reduce the
processing temperature, making the glass easier to form. Silica has often been referred
to as the universal solvent, by glass and ceramic manufacturers, due to its ability to
accept most other ions into its structure while remaining quite stable in the presence of
water, acids and bases, HF being the exception. Additions of other oxides are made to
glass for many reasons; however, they are generally added to increase resistance to
chemical corrosion, increase or decrease optical transmission, to obtain various colors,
and to vary mechanical properties. Glass is also used as a coating for other materials to
provide environmental protection or provide a decorative effect. Glass coatings on a
metal are called enamels and on ceramics, they are referred to as glazes .. In each,
relatively large amounts (1-10 weight percent) of transition metal ions are added to give
a particular color and/or opacity.




                                 (1a)                            (1b)
Fig. 3 Schematic representation of (a) ordered crystalline form and (b) random network .
glassy form of the same composition (Kingery, 1960).
Business Opportunities in Waste Reuse in Iron & Steel Industry                     [4.1/ 4 ]




                                                             Si++


                                                             O 2-

                                                                 Na + or Metal
                                                                 Ions




Fig. 4 Schematic representation of the structure of a sodium silicate glass (Kingery,
1960).


     In the schematic shown in Figure 4, the Na or Si ions could be replaced by a
transition metal ion. The transition metal oxides used to produce color in glasses, glazes
or enamels are CuO, Ti02, Cr203, CoO, Fe203, Mn02, NiO and ZnO. Other heavy
metal ions like Pb, Cd and Sr are also used extensively. PbO is added in as much as 30
weight percent, to provide high index of refraction glasses (commonly referred to as
crystal glasses).
     Basically, the IRC process is a standard ceramic/glass production technique that
uses combinations of silica with additives to form a silicate structure that results in a
polycrystalline ceramic, an amorphous structure, or a combination of the two. In a
standard flat glass (window glass) process, quartz (Si02) is mixed with a flux, usually
some form of sodium oxide (Na20) to lower the melting temperature, possibly calcium
oxide (CaO) or Aluminum oxide (AI203) to increase chemical resistance and transition
and a heavy metal ion to give a specific color or to increase the hardness. (Figure 5)
However, the coloring agent is usually added in the part per million range because the
color desired is a translucent tint and not an opaque solid. Also, hardness is not a
property that is of concern in standard glasses.
      The rather unique deviation from the standard glass process used by IRC is that
we are using larger amounts of heavy metal ions to obtain opaque glass materials (2-5
weight percent) to produce products that have potential marketability. More important,
IRC uses different additives to accomplish this, based on the composition of the waste
materials being processed, in order to adjust the chemistry of the product. Fortunately,
silicate glasses are able to accept relatively large amounts of metal ions into the Si02
Business Opportunities in Waste Reuse in Iron & Steel Industry                         [4.1/ 5 ]


network structure. When the glass cannot accept additional metal ions, the metal
precipitates out of the glass and forms oxides that are insoluble or nearly insoluble in
water and acids
ARKANSAS BLACK GLASS ANNEALED SPECIMEN #1 MICROHARDNESS TESTING
                  DATA Vickers Indentor (200 gf Load)
                                        400Z Magnification


                                                            PHASE I
                                                              882.5
                                                              922.5
                                                              806.0




                                                            PHASE 2
                                                              646.5
                                                              686.1
                                                              652.0




                                                             PHASE 3
                                                               908.9
                                                               1083.6
                                                               970.3



          Fig. 5 400X magnification of Vickers hardness test in the various areas



Environmentally Sound
       The Inorganic Recycling process has been fully evaluated and determined to be a
legitimate recycling activity by the U.S. Environmental Protection Agency and every
state regulatory agency with jurisdiction over Inorganic existing full scale or pilot
operations. As a recycler, Inorganic is authorized to process any inorganic wastes at its
facilities upon completion of the testing Protocols outlined in the initial U.S. Environmental
Protection Agency authorization letter of April, 1990.
Business Opportunities in Waste Reuse in Iron & Steel Industry                                 [4.1/ 6 ]


      As an established recycler with approved standard testing protocols, Inorganic
offers owners and/or generators of hazardous waste a demonstrated, environmentally
beneficial means of ma!1aging hazardous waste, and reduces the liabilities associated
with hazardous waste management to an absolute minimum.
    By analyzing the typical flow of hazardous waste from “Cradle to Grave” the
advantages of utilizing the Inorganic Process becomes readily apparent ( Fig 6 )




By consistently demonstrating that any waste that passes the testing protocols established by
U.S. EPA can be effectively managed through the Inorganic process, the agencies were assured
that neither the initial characterization of those wastes nor the means by which they were
generated are material considerations. Whether such wastes are cast off from chemical
manufacturing, industrial processing, commercial use, incinerator ash, spills arising from
transportation or processing accidents, or residues in pits, ponds or lagoons, all inorganic
hazardous wastes can be legally recycled. Inorganic has commercially demonstrated the
environmentally sound re-cyclability of various plating sludge, Incinerator ashes and residues in
un-permitted pits, ponds and lagoons. Recycling of these wastes by Inorganic results in
environmentally non-hazardous commercial products sold into commerce. Commercial contracts are
in place for sale of IRC material primarily into blast media and asphalt shingles. The prime attribute
of the Inorganic product, over and beyond its unique color and hardness characteristics, is the fact
that the product itself, even at the molecular level, is non hazardous based on U.S. EPA's toxicity
characteristic leaching procedure test ("TCLP").

As illustrated in Figure 6, based on U.S.
       EPA's recycling regulations, wastes lose their "hazardous" label at or before the
time they are placed in Inorganic receiving hoppers at its fully enclosed recycling
facilities. If the recycling facility is located on the site of the generator of the hazardous
waste, those wastes lose their "hazardous" title and become hazardous raw materials
immediately upon movement into the recycling process, whether from the generator's
initial collection unit or upon excavation and transport to the Inorganic facility. Because
Business Opportunities in Waste Reuse in Iron & Steel Industry                            [4.1/ 7 ]


of this shift in legal characterization of these materials, Inorganic is willing to take title to
the materials early in the recycling process.
     Once within the Inorganic facility, these once "hazardous wastes" are managed as
hazardous raw materials. Upon entering the Inorganic thermal processing unit, the
materials lose their hazardous characteristics through the crystal and chemical bonding
that occurs with additives chosen specifically for the incoming material's chemistry.
Through further refinement of these additives, Inorganic is able to "tailor" its product to
meet the unique chemical specifications of Inorganic's customers.
     Throughout the whole process, records are kept on the results of initial testing
protocols, the quantity and chemistry of the incoming materials and the quantity and
chemistry of the outgoing products to assure that the transformation of the "wastes" into
nonhazardous commercial products has been successfully completed. Any spills or off
specification products produced can be reintroduced into the mixing vessels within the
Inorganic facility.
      Under U.S. EPA's recycling guideline, any "hazardous waste" that is recycled and
incorporated into a commercial product, losses its original label as a "hazardous waste"
as a matter of law, and is therefore no longer regulated as a waste. Having severed the
legal and chemical "liability trail" normally associated with hazardous waste operations,
both Inorganic and the original generator of the wastes are thoroughly and completely
isolated from future hazardous wastes liability associated with commercial products
shipped. Once in commerce, the Inorganic products are regulated merely as a function
of normal industry guidelines, including compliance with manufacture safety date sheet
specifications.
      Generators doing business with Inorganic are invited to periodically inspect the
Inorganic operations and records maintained to confirm the complete recycling of the
original wastes into the products and assure themselves of the legal and chemical
sufficiency of the recycling process. Any dusts generated in the course of hazardous
material processing are collected in approved air pollution control devices and
introduced back into the recycling process with the initial hazardous materials. Any
product that does not completely satisfy the customer's specifications could be simply
reprocessed back through the kiln.
     Inorganic Recycling has been active in the true recycling of inorganic materials
since 1988. Chrome plating waste was the first material approved by the EPA for this
method of recycling. The first EAF dust recycling unit was started in 1992 in Arkansas
and it is also approved by the Federal and State EPA as true recycling.
Business Opportunities in Waste Reuse in Iron & Steel Industry                       [4.1/ 8 ]


                                             ROOFING

                         Face
                       granule
                      12/30 mesh                                    Backing
                        angular                                       coIor
                                                                   unimportant
                                                                    angular to
                                                                    spherical



                               500,000
                               tons per
                                 year




          Fig. 7 Schematic showing various aspects of a typical roofing shingle.


     The IRC recycling process has now been proven in full scale commercial
operation. It has demonstrated the ability to recycle a continuous flow of EAF dust into
salable products since May, 1995. For over eighteen months, with the exception of a
few planned outages, IRC has recycled EAF dust every day, and has sold all products
as originally produced. Every pound has been "right" the first time.
      EAF dust and other feedstock materials, custom engineered to produce' products
meeting customer standards, are mixed and fed into the recycling kin and molten
material is tapped out, continuously. The molten glass ceramic products is routinely
sized to customer requirements and shipped. Due to proximity to the Mississippi River,
barge shipment provides low cost transportation. Shipments are made approximately
once every six weeks. All dust sent to the IRC facility is recycled and sold. No materials
are buried. No materials are returned to the mill. Currently, virtually all IRC products are
used as roofing granule materials and provide home owners with a consistent, more UV
resistant product.
Business Opportunities in Waste Reuse in Iron & Steel Industry                  [4.1/ 9 ]


      All products, without exception, produced by IRC have passed the EPA's TCLP
test and of equal importance, have met more rigorous customer specifications. We have
no reason to doubt that record will continue well into the future.
     No other on-site EAF dust recycling system can match the IRC record as a proven
process. Except for the few well established dust disposal alternatives, no other dust
handling system can match the IRC record as a proven process.




     One reason for this success is that the IRC process simply adds special know-how
to well understood glass-ceramic processing methods. Basic methods are highly flexible
and well able to meet the challenge of different sources and dust composition, normally
encountered. Custom engineered feed stocks are added to EAF dust in a manner
designed to assure that all product specifications are met. The melting process is
designed to accommodate dark glass and to accept changes while continuing to meet
specifications. Both dry and wet scrubbing systems are in place to address any off
gases from the kiln that may contain sulfur, chlorides and fluorides.
     The current unit processes dust at a rate of 12,000 TPY. A new unit (one kiln) is
designed for 20,000 TPY dust and will come on stream in late 1997. The new unit will
incorporate both oxyfuel and electrical resistant heating. The new unit will also'
incorporate various methods of forming the end product that will allow such steps as
beading, forming, fiber forming, coating, annealing, shapes, etc. both Alternatively
and/or simultaneously.
Business Opportunities in Waste Reuse in Iron & Steel Industry                    [4.1/ 10 ]


Most Economical Solution
     Inorganic Recycling Corporation (IRC) is positioned to offer the best economical
environmental solution to the EAF dust problem over the next several years. This is
possible due to four major factors:
      - Shipping Cost - The practical size of an IRC VIT processing unit is suited for on
site application where the dust is generated. A typical unit can process 10,000 TPY,
20,000 TPY or multiples of these. Shipping, even by rail, can typically add $20/ton to
$30/ton to the bottom line cost of processing. Markets for the end products are
distributed evenly across the United States and shipping costs are absorbed into the
cost of sales.
     - Raw Material Costs - Frequently, raw materials are conveniently located right at
the generators site in various forms of silica, alumina, calcium, sodium, spent refractory
and slag.
                                Potential Raw Materials (Fig. 9)
                            Spent Refractory and Grog             Slag
                Si02             50 to 65%             CaO         47%
                A1203            39 to 25%             Si02        23%
                Fe203            1.5 to 2.5%           Fe203       20%
                CaO              0.8 to 0.6%           MnO         4.5%
                MgO              0.3 to 0.7%           MgO         3.5%
                Ti02             1.0 to 1.5%           Cr203       .5%
               lkalies           2 to 3%               A103        1.0%

                      Cullet or Ground Glass (Fig. 10) Soda Lime Glass
                                  Plate        Flint       Amber Emerald
                         Si02     73.25       73.21       72.45   72.26
                         Na20     13.45       13.45       13.01   13.11
                         CaO       8.58       10.332      10.48   10.47
                         MgO      3.77    1.04             0.68    0.78
                         Fe203 0.356     0.081             0.31   0.205
                         A1203 0.28       1.34             1.95    2.05
                         S03      0.19    0.16             0.03    0.08
                         K20      0.11    0.40             0.44    0.93
                         PbO    0.0037 .
                         Cr203 0.0023    0.0026              -     0.12
Business Opportunities in Waste Reuse in Iron & Steel Industry                     [4.1/ 11 ]


     These materials provide an excellent lowcost source of feedstock, often solving
other disposal problems.
     - Energy Costs - Energy costs can be kept to an absolute minimum by using
evolving technology of oxy-fuel burners combined with electrical melting to allow
optimum melt bath depths. Computer technology and modeling allow precise sizing and
placement of both these technologies. Use of excess heat from the VIT exhaust will also
be used for pre-heating and annealing.
      - Value Added Product - Inorganic Recycling is more than a Recycler of EAF dust.
We are a manufacturer of end products that will continue to be of value well into the
future. The potential market for IRC's glass ceramic products is very large compared to
the amount of products that can be produced from EAF dust. Dust generation in the
U.S. is about 0.8 million TPY. If IRC recycled all of that dust into products, about 1.2
million TPY of product would be manufactured. The glass-ceramic market in the U.S.
today is 800 million TPY.
    A broad market for large quantities if IRC products has already been identified.
Long term commitments, for the sale of all current production, are in place. Additional
demand exists for more products in the current applications.
     The new applications include abrasive grains for metal cleaning and conditioning
which are superior to current available materials. Other products are being investigated
through IRC's Product Development Program. (Figure 13) That program is targeting
higher value uses for IRC products that will bring benefits to customers, steel mills and
IRC alike. Promising developments are already being realized. Products can be altered
either chemically and/or by varying post
     Forming treatment such as annealing. (Figure 11 and 12) A significant increase in
the value of IRC products is expected over the next decade. Benefits from the sale of
higher value products are available to steel mills since IRC will share those benefits as
they are realized. It is expected that recycling fees for dust generators will decline as a
result of benefit sharing.

     Conversely, fees for land filling can be reduced only if, and to the extent that costs
can be not only contained, but reduced, despite inflationary pressures.

     The same is true of metals reclaiming processes since the market price of zinc and
other reclaimable metals is projected to be relatively fixed compared to the value of IRC
products.
Business Opportunities in Waste Reuse in Iron & Steel Industry                                  [4.1/ 12 ]




Developmental Glass Melting System
      Fig. 13 Concept sketch of IRC's Developmental Kiln with oxy/fuel and electrical
heating.

Summary
        Inorganic Recycling has now Commercially demonstrated an economical, reliable
vitrification system for processing EAF dust. Further refinement of the end product using our
own developmental unit and full scale commercial units will further position the IRC process
to be the most environmentally sound and the most economical process available for the
next several years.

References
    1. Introduction to Ceramics, 1960.
    2. J. Wiley and Sons W.D. Kingery M.LT.
    3. American Ceramic Society Ceramic Bulletins 1994 thru 1996
    4. Ceramic Industry, July 1996 Business News Publishing Co.


          This Paper is Printed with Permission from: Pacific Sterling Technologies, Inc. USA
                                     For Plant Set up, please contact:

                            Mr. Shankar Chowdhury, President BD & Proj.
                                      Zoom Developers P Ltd.

                 Poonam Building, 3rd Floor ; 5/2 Russel Street ; Kolkata - 700 071,
                         Phone : +91 33 22263669/70 ; Fax : +91 33 22263668
                           Director (Projects & Business Development), Steel
                  Mobile : +91 9831899469 ; E mail : shankarc@zoomdevelopers.com
Business Opportunities in Waste Reuse in Iron & Steel Industry                      [4.2 / 1 ]


         RECOVERY AND USE OF STEELMILL IN-PLANT WASTES
                            (Taken over by Pacific Sterling Inc.)
                     Paper printed with Permission from Pacific Sterling

                                         T.C.INC
                     26363 S. TUCKER RD., ESTACADA, OR 97023
                                  PHONE: 503-630-6759
                                   FAX: 503-630-6759
                                EMAIL: tcinc002@aol.com
   (originally written and published in Europe in 2005 as a processing technology for
                        Waste Recovery and for Direct Steel Making
   Modified and rewritten for publication for (Indian Institution of Plant Engineers and
                              SAIL (Steel Authority of India)
           International Seminar on Waste Management In The Steel Industry
                                      May 9/10, 2008

     Abstract: In 2005, 2006 and 2007, over 1 billion tons of steel were produced each
year worldwide, an increase from 800 million due to developing markets in China, India
and a few others. This increase in steel production, and resultant use of raw materials,
iron ore and coking coal, has spurred a major shortage in the raw materials and more
than doubled the price for the entire world. New strategies are being developed to
secure raw materials for the future, investments in mines, investments in scrap steel
and exports, opening of new mines or re-opening of old ones and so on and so on.
     All the while, during the processing of iron ore from the mine to the rolling mill, 10%
of the iron ore used to make this billion tons of steel is thrown away as waste. That
seems to be a figure of over 100 million tons of iron bearing materials is mostly thrown
away. According to the steel mill operators, this waste is too difficult to handle, it will
upset the normal operations, there’s more where that came from, let the accountants
deal with it. If you look at the invested cost in producing the waste, perhaps the
accountants should deal with it. What is the cost of steel, for example, in the rolling
mill? On average, mill scale accounts for 10% of the waste, is the highest quality iron
oxide you can find and has an invested cost to the steel maker of over $400 a ton. In
the US, the normal practice of getting rid of mill scale is to sell it to cement plants for
$10 per ton, or less, while striving to purchase other iron units and repeat the practice.
This same philosophy of handling waste iron units from ore screenings and dust, mill
scale and spillage, hazardous waste handling, landfill costs and fees has to be reviewed
with a strict analysis on cost, environmental effect, wasted energy and replacement of
raw materials. Restricting progress in overcoming the environmental, energy and waste
issues has been the inability to treat fine materials. Some methods that have tried to
recover wastes or to use fines contribute to further use of energy and pollution.
Business Opportunities in Waste Reuse in Iron & Steel Industry                     [4.2 / 2 ]


     The iron and steel industry in the U.S. has issued criterion for a Direct Iron and
Steel making process, for the future, that should be developed over the next 20 years.
The process criterion, uses coal directly, eliminates wastes, reduces emissions, reduces
costs and energy and uses iron ore fines.
       A new process that meets all the criterion has been developed which provides for
an agglomeration of iron bearing materials fines, premixed with coal or other carbon
sources and fed directly to a smelter, eliminating the need for coke, pre-processing of
feed materials, sintering and pelletizing and eliminating air pollutants and energy
consumption from those processes, while also recovering iron bearing wastes and
utilizing other wastes from iron and steel making processes.
     The technology, called the RBI Process, for which T.C.Inc. has been issued a U.S.
Patent, includes the agglomeration of feed materials, mixed with a carbonaceous fuel,
to produce a self reducing feed to a smelter. The selected agglomeration technique is a
hydraulic ram briquette machine, which will produce feed material to withstand any
handling, maintain strength and integrity during processing, penetrate any slag barrier
and maintain strength during the reduction. The ram briquette machine was also
selected to reduce or eliminate use of binders due to its inherent ability to make an
agglomerate of high density. The research phase of the RBI Process was completed in
the 80’s. Technology and designs now developed include the methods to make hot
metal from the waste and ore fines, use of coal instead of coke, operating a steel mill
100% waste free, reducing capital costs, reducing or eliminating in some cases,
greenhouse gases, reducing energy and building an iron making or steel making plant
from 50,000 TPY and up on a competitive scale with large capacities.
    While the selection of a smelter for Direct Iron Making will follow the route of an
oxygen furnace, the technology will utilize any existing melter/smelter for the recovery of
waste, since most wastes recycling has to be site specific.
     Additional technology is also being developed to utilize this processing method for
the non-ferrous and ferrous –alloy industries, such as directly making stainless from as
mined materials, such as nickel laterites, and using any waste carbon sources such as
wood from forest fires and other sources of wastes.
Review Of Technology
      In the 1980’s in the US, it became apparent that iron and steel plant wastes,
emissions and effluents were a cause of concern due to, ground water contamination
from stockpiling or land filling, air born particulates were contaminating soils in
surrounding plant areas and there was concern of the greenhouse effect from gas
emissions. As a result, restrictions were put on land filling and stockpiling of wastes
and air born emissions from plants and a new era of monitoring and control was
Business Opportunities in Waste Reuse in Iron & Steel Industry                    [4.2 / 3 ]


established. The added cost to iron and steel making then dictated that new
technologies be developed for collecting the emissions and effluents and treating the
collected materials to reduce leaching into groundwater and potential health hazards.
The iron and steel industry, since, has incorporated new technology in reducing
particulate emissions from air born sources and in collecting wastes. Some methods
have also been incorporated to recycle, through existing processes, the sinter plant for
example, wastes that have no ill effect on production capacity or quality from
contaminants. Greenhouse gas emissions have also been reduced with increased plant
efficiencies. However, no technology had been implemented, en-masse, to recover and
use waste materials.
      Iron and steel plant wastes are normally categorized into iron bearing materials,
refractories and carbonaceous materials. Methods to recover any or all of the wastes
needed to be developed. Waste materials from iron and steel making plants were
studied. This included mining and beneficiation and pelletizing operations, material
shipping , sinter plants, coke oven plants, integrated iron and steel plants and EAF and
DRI operations. The physical characteristics of the wastes revealed that, with the
exception of slag, most iron bearing materials were in the form of minus ¼ inch, most
refractories were in the form of brick or large particles, carbonaceous materials were
liquid, dust or breeze or in the form of graphite rods. The chemical or elemental form of
wastes, especially the iron bearing materials from various iron and steel plants each
had compositions specific to those iron and steel plant operations and products. The
refractory waste and carbon graphite needed to be separately reviewed due to size and
potential reuse. The major emphasis was put into finding a means to handle iron
bearing wastes of all the various operations for a case by case and site specific
scenario.
     Handling the fines and dust and collecting them was not the issue, as technology
and equipment was readily available to do this. Making the iron bearing wastes a
reusable product or in some cases a non-hazardous product became the objective. To
do so various technologies were reviewed:
       a. Pelletizing and induration and cold bonded pelletizing. These required the
          materials to be ground to normal pelletizing grade feed, required the addition
          of unwanted binders, and added an element of handling in induration or
          curing. The product pellet still generated dust and fines and added to
          chemical constituents undesirable in further processing. The cost associated
          with any site specific case could not be justified. Shipping materials to a
          central location for a more economically sound project only added to the cost
          in handling the materials and the materials would then be mixed and
          unacceptable to any specific site for reuse.
Business Opportunities in Waste Reuse in Iron & Steel Industry                       [4.2 / 4 ]


       b. Roll type briquetting or brick making This technology provided that any
          materials of less than ¼ inch could be used without grinding. However,
          binders were required far in excess of pelletizing adding to the unwanted
          chemical constituents in further processing. The briquettes also had to be
          cured to increase the strength, but, handling and shipping still caused
          generation of fines and dust. Again, the cost of briquette operations and high
          maintenance costs of machines eliminated the justification for commercial
          use.
     In both type technologies, pelletizing and briquetting, or brick making only
integrated iron and steel plants could reuse the materials for recycling. EAF operations
waste iron bearing materials contained hazardous materials not suitable for recycling
and the EAF operations are not an iron making or iron reduction facility.
       c. Pre-reduction studies were then made in order to provide a feed material that
          was of more value to the iron and steel maker. Processes were developed to
          use the technology of pelletizing or roll briquetting for a cold bonded feed to
          rotary kilns, rotary hearths and shaft furnaces with carbon added to the pellet
          or briquette.      The technology was adapted in some operations and
          subsequently shutdown due to high operating costs, high capital costs with
          few benefits to the iron and steel maker. The technologies also required
          carbon sources of the highest quality, coke, and added the same chemical
          constituents from binders, defeating any benefits to steel making.
       d. Pre-reduction and smelting, as a combined process was also studied, not
          only for recovery of in-plant wastes but to directly make iron from fines. This
          technology also requires the highest quality feed and carbon sources,
          pelletizing and major capital investments. Operating costs can only be
          justified with large scale plants, therefore contributing to added iron and steel
          overcapacity. The only recognized benefit is the use of coal instead of coke.
          Later developments abandoned the recycling of wastes.
       e. Direct steelmaking has been considered, to use fines and coals, not of coke
          quality, and smelt/reduce materials directly. This had been considered as the
          most viable technology under development, which could use recycled iron
          units, dust and fines, directly, however, no studies are being conducted to use
          waste materials. The technology also is limited to only large scale operations
          to justify operating and capital costs and is not viable for site specific cases in
          recycling wastes. Material losses from fume exhaust also reduce efficiency
          and carbon additions are far in excess of the requirements of stoichiometric
          reduction. Fines and dust feed do not penetrate slag barriers without injection
          systems.

Process Development
      The requirements to handle the iron bearing wastes and fines had the following
criterion:
Business Opportunities in Waste Reuse in Iron & Steel Industry                      [4.2 / 5 ]


            •    Carbon wastes products or non-coking coals should be used.
            •    Site specific
            •    As-available iron bearing wastes, with the exception of slag, had to be
                considered.
            •    Product must have the integrity to withstand the reduction phase during
                reduction/smelting.
            •    Product must withstand any handling or shipping with minimal losses.
            •    Product must be heavy enough to penetrate any slag barriers.
            •    The addition of a carbon source should be limited to carbon required for
                reduction of oxides and the carbon equilibrium in the hot metal.
            •    Product should be able to be fed to any melter/smelter.
            •    Minimal energy use.
            •    Minimum additions of materials, such as binders. Maximum use of other
                in-plant waste, such as refractories
            •    Iron fines of less than ¼ inch had to be used.

     Hydraulic ram briquetting was then reviewed and it met all the criterion listed.
Historically, the ram briquette machine had been used commercially since the 1930’s for
the “punch pressing” of machine shop turnings and borings for feed to a foundry. This
practice has been continued through today. Tests were then conducted on various iron
and steel mill wastes, singularly without binders. Both iron bearing wastes and carbon
sources were tested, then in combinations, simulating typical site specific cases. In
some instances refractory material was crushed and added. If dust collection material
was used, only, the product briquette was somewhat weaker. This was compensated
for by the addition of a tar or pitch or coal and in some cases ground refractory. By
mixing dissimilar sized particles, no binders were required. However, by adding a
carbon source of some waste materials or coal, it was found that the material had an
inherent binder. It was also found that oxides would be self reducing upon feed to a
smelter.
      Since the ram briquetter is a known technology, can produce an agglomerated
product from fines with mixtures desirable to the iron and steel maker, can utilize and
agglomerate any iron and steel wastes and can provide a self reducing feed material, it
was expected that the technology meets the criterion for direct iron and steel making,
ahead of its time. The technology is viable, in that it can be utilized at any site specific
plant, in any size to meet the requirements of capacities. The only inputs required,
other than feed equipment apparatus are cooling water for hydraulic cooling and power,
making it also environmental friendly, as compared to any other process which may
require induration, pelletizing or pre-reduction and therefore use of hydrocarbon fuels
with resultant gaseous emissions. This process can claim total use or recovery of all
iron and steel wastes.
Business Opportunities in Waste Reuse in Iron & Steel Industry                        [4.2 / 6 ]


     The process also will utilize direct feed of as mined iron oxide feed, not ground to
meet pelletizing or concentrated feed to sinter plants. The material feed will be mixed
with coal fines or waste carbon sources and ram briquetted to provide a smelter with a
feed material that is self reducing. This will eliminate the need for pelletizing or sintering
and the use of coke making plants. As compared to pelletizing, sintering and coke
plants, no fuels are used, no gaseous emissions are experienced, there are no losses of
materials, capital expenditures and operating costs are reduced.
      Other benefits are derived from using the ram briquetted technology, in that
imports of feed materials can be reduced and curtailed, or an area of low need for iron
or steel goods can build a micro plant, suitable for its local needs and using low quality
ore and carbon sources.
     The potential application to the iron and steel industry is the recovery and use of all
iron bearing wastes, the potential application to replace sinter and pellet plants, the
potential of replacing coke ovens and using coal directly.
       The research objective addressed the specific need for improvements in the iron
and steel industry to; increase efficiency through recovery of iron and steel wastes and
through the use of iron oxide fines in making iron, decrease the dependence on coke by
using coal directly, decrease the gaseous emissions in pre-processing, sintering,
pelletizing of iron oxides and coke making plants and decrease the energy consumption
in pre-processing, sintering, pelletizing, coke making and energy losses due to waste
materials. In 2005, over 1000 trillion Btu’s were invested in energy to produce waste
iron bearing materials and over 1500 trillion Btu’s were used to pre-process, pelletize
and sinter iron oxide fines. The goal is to recover the energy invested in wastes by
utilizing the waste and to reduce the energy consumption in pre-processing, pelletizing
and sintering.      The objective is to use coal directly, eliminating the need for coke
making. Additionally, it is the objective to eliminate the gaseous emissions by
eliminating some steps in pre-processing and to eliminate sintering, pelletizing and coke
making.      These goals will be accomplished by using an alternate method of
agglomeration, iron oxide mixed with a carbon for direct feed to a smelter and feeding
any type smelter that hot metal can be produced. It will not be necessary to develop a
new machine for agglomeration as the process technology uses a well know hydraulic
ram briquetting machine.
Technical Feasability
     To make iron and subsequently steel, carbon is used, under heat, to chemically
extract the oxygen from the natural oxides of iron. Most processes convert some sort of
carbon source or hydrocarbon source into a reductant CO and/or H2 to be introduced
as a gas, externally to the iron oxide and extract the oxygen from the iron, by forcing the
gas through the iron oxide particle, producing somewhat of a pure iron, then the iron is
Business Opportunities in Waste Reuse in Iron & Steel Industry                      [4.2 / 7 ]


melted. The process is more complex as there are also other elements combined with
the iron and carbon sources that are dealt with separately and there are major
considerations as to how to get the gas into the iron oxide material. However,
simplistically, this is what occurs. In order to make this processing as efficient as
possible, iron oxides have been meticulously beneficiated, such that, a maximum value
of other materials is reduced, but, the iron oxide is then in a form that can’t be used
unless it is agglomerated, normally by sintering or pelletizing. Shaft furnaces, namely
the blast furnace also has been designed for the purpose of accepting iron oxides in the
form of sinter and pellets. In order to have a carbon source for reduction in the blast
furnace, efficiency dictated that coal could be used but it had to be beneficiated by
removing the volatiles and other matter that would interfere with quality of hot metal
and the coal had to be more permeable to achieve efficiency, resulting in the processing
of coal to coke. It is the intent of using a ram briquetted mixture of iron oxide particles
and coal particles, tightly bound through compression as feed to a smelter. At elevated
temperatures in a smelter the carbon will oxidize by the extraction of oxygen from the
iron in the particle next to it. Gas flow and bed permeability is, therefore not a concern,
only heat. The ram briquette becomes a self reducing material and in the smelter,
within minutes is reduced of oxides and melted into hot metal. Since the reduction
takes place inside the ram briquette, it is anticipated that close to stoichiometric carbon,
plus carbon equilibrium, can be achieved
     Reducing current energy usage, recovering iron and steel making wastes and
eliminating steps in pre-processing, sintering, pelletizing and coke making, using coal
directly and reducing gaseous emissions were the achievements desired. Selecting the
type smelter to achieve the desired hot metal results will be a goal as well as type of
heat input. It will be a goal to review the potential of heat recovery in off gases for
cogeneration of power based on various types of carbon input. Another goal, and
considered in the developmental phase, is to apply the technology to the non-ferrous
and stainless industries, such as nickel laterites and aluminum bauxites and others.
Benefits
      The energy consumption for the RBI process to recover the world’s 100 million
tons of iron bearing wastes is 30 trillion Btu’s/yr, as compared to 1000 trillion Btu’s used
to make the waste. The per unit energy consumption is calculated at 40 kWh per ton
electrical power input. (per unit installed process is an engineering calculation of a ram
briquetting facility, including all materials handling, mixing, feeding mechanisms and the
machine requirements of a hydraulic system.) There is no comparable or competing
technology that is used to recover and use iron and steel plant wastes. Some captive
sinter plants are feeding some acceptable wastes into the process, however, sinter
plant energy use is about 1.6 million Btu’s per ton of combined energy consumption.
Business Opportunities in Waste Reuse in Iron & Steel Industry                    [4.2 / 8 ]


Therefore if wastes were recycled through sinter plants the energy required would be
about 160 trillion Btu’s.
     Processes that use iron oxide agglomeration and pre-reduction, such as rotary
hearth technologies or other techniques before feed to a smelter will consume a
minimum of 15 million combined Btu’s per ton. In recovering the iron bearing wastes
the energy consumption is 1500 trillion Btu’s. As compared to ram briquetting the
energy savings with RBI is 98%.
      To replace coke ovens, sinter and pellet plants, the blast furnace would also have
to be modified or replaced with an alternate smelting/steel making technology, for
example an oxygen furnace. Overall benefits to the iron and steel industry are in the
preparation of materials, the development of a site-specific technology, reduction of
effluents and total recovery of wastes.
     The technology is designed to recover iron and steel plant wastes in the form of
iron bearing materials, carbon products and other wastes, such as refractories or lime
dust. Through this technique, about 10% of total steel production can be recovered and
reused, improving the productivity and cost of making steel. The proposed technology
also has the potential of replacing processing steps in iron and steelmaking in materials
preparation for smelting. It is anticipated that by using the patented process of ram
briquetting, hot metal can be produced at a significant savings over conventional
methods through energy savings alone.           If capital costs, operating costs and
maintenance costs of conventional equipment were included, it is anticipated the
savings in costs per ton of prepared materials would be in excess of one half.
Environmental Benefits
       There are no wastes associated with using ram briquetting technology as a feed
preparation for materials to the iron and steel sector. 100 million tons per year of iron
bearing wastes associated with the iron and steel sector are already being produced
which can be recovered with ram briquetting. With existing technologies, sintering or
pelletizing of iron oxides and coke making,, CO2 emissions would be eliminated by
using ram briquetting technology. Currently the amount of CO2 emissions are
calculated from sintering (assuming pelletizing uses the same relative amounts of fuel)
and pelletizing at 69 pounds/ton of steel and coke making at 102 pounds/ton of steel. .
Wastes and by-products of coke making are also eliminated, but, with new smelting
technologies, effluents now that exist will be changed and have to be studied. It is
suspected that the selection of the smelting furnace with the ram briquette will greatly
enhance the use of all carbon and hydrocarbon products in coal and reduction of NOX
with the use of enriched air.
Business Opportunities in Waste Reuse in Iron & Steel Industry                       [4.2 / 9 ]


How To Get Started
  A. To recover iron bearing materials at the mine or the beneification plant, pellet
     plant, sinter plant, DR plant or steel mill do a complete mass balance of all
     materials. At each step put a value and physical and chemical analysis next to
     the waste, iron bearing materials, carbon, lime, etc.
   B. To make steel or a ferrous alloy from as mined materials do a sourcing analysis
      of local ores and carbon sources, putting a value and analysis of the materials
      as-is
   C. For a mixture of the materials to be self reducing in a smelter 1 carbon is added
      for each oxygen attached to the iron, plus a bit of carbon to make sure the
      atmosphere and equilibrium is reducing. Therefore, this mixture will give a feed
      capacity on an annual basis. Ram briquette machines can be purchased with
      annual capacities from a few thousand tons per years to 25,000 tons per year for
      a single machine. Any smelter can be used to make hot metal or even cast iron
      in any capacity and depending on local fuels, power availability. It is not
      necessary to build an oxygen smelter but over the long term it will be the
      cheapest to operate.
   D. Make an analysis of the products you wish to make and then select the
      downstream facilities you need to make them, whether it is casting or making
      hand pumps or rebar or just providing hot metal for the steel mill next door. (you
      can also just make feed materials for the smelter customer with a stable known
      feed material for his operation.)
   E. RBI product does not have to be stored with any particular restriction, outside is
      fine and in stacks. The density of RBI briquettes is about 5 g/ml so there is no
      need for any protection from absorbsion of moisture. .
   F. Capital costs to make RBI briquettes can be calculated on total local supply of
      conveyors, mixers, bins, weigh feeders. The ram briquette machine is the only
      part needing to be imported at the present time as the alloys for the ram and dye
      have to be carefully made to handle iron ore roughness. The smelter, if an
      oxygen furnace is used can also be made to almost any size and can be made
      locally. Supply of oxygen can be supplied from any commercial gas supplier and
      heat recovery for co-generation of power to be self sufficient with a sustainable
      operation also can be supplied from any technology. After you have reviewed
      the total cost of putting in ram briquetting equipment, make a comparative cost of
      installing a DR plant, a pellet plant with all the beneficiation or a sinter plant, and
      add a coke plant. In smelting of iron ore pellets and coke and/or sinter add a
      blast furnace. In the DR route, in addition, add a pellet plant, then an EAF or
      induction furnace. If the ram briquetting or RBI process is selected, just add a
      BOF shop of the size needed. We think the capital cost will be obviously low at
      about ½ or less for RBI. Operating costs are equally low using ore fines and coal
Business Opportunities in Waste Reuse in Iron & Steel Industry                   [4.2 / 10 ]


       instead of pellets, sinter or sized lump and using coal instead of coke. The only
       water for RBI is cooling water for the hydraulics. Manpower costs are at a
       minimum since there is no special training involved and no IT degree required
       nor expansive instrumentation. Care can also be given to total recycling
       therefore no landfill, 100% free of waste, and most importantly reduce your
       materials purchases by 10%.
   G. Care can also be given to total use of all in-plant waste materials or use of fines
      and local coals, a steel mill 100% free of waste. A total sustainable operation.
      Elimination of material preparation high cost operations and green house gas
      emissions.

References cited
   1. Energy and Environmental Profile of the U.S. Iron and Steel Industry, August
      2000, by Energetics, Inc., prepared for the U.S. DOE, OIT.
   2. Steel Industry Technology Roadmap, December 2001, published by the AISI in
      cooperation with the U.S. DOE.
   3. Theoretical Minimum Energies to Produce Steel, March 2000, Carnegie Mellon
      University, Published for the U.S. DOE
   4. Energy Use in the U.S. Steel Industry, September 2000, John Stubbles,
      Published for the U.S. DOE
   5. U.S. Patent # 4,917,723, issued to applicant, Thomas J. Coyne, jr., assigned to
      T.C.Inc., April, 1990.

     T.C.Inc. is an international project development and consulting firm dealing in iron
and iron bearing materials in the fields of agglomeration, beneficiation, pelletizing and
reduction. The makeup of T.C.Inc. includes associates and associated companies with
expertise in iron and steel making technologies, gas reforming and burner systems and
syngas technology.       T.C.Inc. provides services in technology development and
evaluation, project evaluation, process evaluation and application, project, construction
and operations management, plant commissioning and training and operations
optimization. T.C.Inc. also offers patented technology in Direct Reduction of Iron
Oxides with any fuels, Increase in Capacities with a Shaft Furnace DRI Technologies of
20%, DRI and the Rotary Hearth and Rotary Kiln and the patented RBI Process for
Direct Iron and Steel Making and Waste Recovery.
      Thomas J. Coyne, Jr., the author has published papers in iron and steel making
technology that cover such areas as raw materials for iron making and direct reduction,
direct reduction plant operations, shipping and reoxidation of direct reduced iron,
pelletizing of magnetite, gas flows and pressure considerations in shaft furnaces, shaft
furnace balances and assumptions, raw material plants mass balances, international
project development and management.          He has also been involved in technology
transfer of these technologies to developing nations for the past 40 years in the iron and
Business Opportunities in Waste Reuse in Iron & Steel Industry                 [4.2 / 11 ]


steel industries from mining to finished products and has developed a free email
advisory service for these areas, specifically for deserving third world nations coming
into their own.
      This paper is a product of T.C.Inc., copywrited by T.C.Inc. and the technology
displayed may not be used or copied without the express approval of T.C.Inc. and
follows applicable law of the US Patent offices and US Dept. of Commerce.
Business Opportunities in Waste Reuse in Iron & Steel Industry   [4.2 / 12 ]
Business Opportunities in Waste Reuse in Iron & Steel Industry                        [4.3 / 1 ]


      USE OF PLASTIC WASTE IN IRON AND STEEL INDUSTRIES –
              AN APPROACH FOR ENERGY REDUCTION

                                       R.B. Gupta, G.C Pattnaik
                                  Sail, Rsp, Rourkela – 769011
                                E-mail : rbgupta@indiatimes.com




      Abstract: The major Iron and steel producers in the world, as their voluntary
energy saving action plan, proposed a more than 10% energy reduction by 2010 with
1990 as the basis. Further, some steel major has put forward an additional more than
1.5% energy by the use of waste plastics as a metallurgical raw material. Coke –
making process and Blast furnace process of Iron making are considered to be
promising area to which the thermal decomposition of waste plastics is applicable
because the process involves coal Carbonization in a light temperature, reducing
atmosphere. Some plants in Japan has started using waste plastics in coke oven and in
Blast Furnace injection. In coke oven 1% addition of waste politics in raw coal did not
deteriorate the coke strength. In Blast Furnace addition of plastics in injection process
improves the thermal regim of the furnace and results in coke rate, reduction in slag
volume also. In India there is too much scope of recycling waste plastics in steel
Industries as the plastic waste generation is more than 6 million tones and this can
solve some extend the shortage of coking coal problem for Iron and steel Industries
particularly for Blast furnace process of Iron making. This paper outlines technology of
recycling businesses that make the best use the iron and steel making process of the
steel works.

Introduction
       As the advent of the 21st Century, mankind is facing global environmental problem,
causing the industrial sector to take initiatives in establishing recycling for the efficient
utilization of our natural resources. By effectively utilizing the synergistic effects of Iron
and steel making technology and engineering technology built up through its long
history. In the world due to energy crises, major steel makers tackling issues related to
conserving energy and resources as well as protecting the environment throughout the
world. The plastic is most commonly used in many plants of world for sample India
during 2003 about 4 million tones of plastic waste were discharged and in Japan this
figure was as high as 9-8 million tones (1999) in USA. This was many times than Japan
and India. Out of the world total plastic waste only 33% is effectively used and balance
were disposed of by land filling. See Table No.1, plastic waste generation in India. The
Business Opportunities in Waste Reuse in Iron & Steel Industry                     [4.3 / 2 ]


growth of plastic industry is more than 17% against the population of about 1 billion and
this growth is further expected to rise due to mineral water bottles.
Table No. – 1 : Plastic Waste generation in India (2007)
                            1995-96              2001-02                     2006-07
 Total polymers              1889                  4374                       8054
 Process waste                 38                   87                         161
 (2%)
 Post Consumption
 Waste                     870 (46%)           1966 (45%)                 3624 (45%)

      The trend of plastic use in India has been shown in Table No. – 2
Table No. – 2 Plastic uses in India (2007)
 Polymer              1995-96                        2001-02         2006-07
 Polyethylene (PE)    823                            1835            > 3500
 Polypropylene (PP) 340                              885             > 1800
 Polyvinyl Chloride 489                              867             > 1400
 (PVC)
 Polyethylenetero     34                             140             > 300
 phthalate (PET)
 Others               203                            647             > 1500
 Total                1889                           4374            > 8054
 Plastics packaging 976                              2272            4037
 % of packaging       52%                            52%             > 50%

      PET – bottle production
               840 million     2000
               6 million       2006
     In many parts of the world 50% plastic waste collected as general waste is
recycled today. Recycle waste is used as or for raw material around (4%), chemical
resources (3%), solid fuel (1%), waste power generator (35%) and heat source (7%),
However, the remaining half is disposed of at landfill causing environmental hazards.
Basic question how to put plastics in a recycle net, So that like steel recycling, plastics
also can be recycled in 100% productive use without affecting the economy and the
environment for this purpose. Iron and steel Industries has shown the ways to use
recycle plastic as partial substitute of coke in Blast Furnace and in coke oven also.

Recycling of waste plastics in Iron and steel Industries
Business Opportunities in Waste Reuse in Iron & Steel Industry                     [4.3 / 3 ]


Recycling as Blast Furnace feed material

Case Study (I) Chemical Recycling
      In an iron making blast furnace, coke is gasified into, CO, and used for reducing
Iron ore into iron. Waste plastics can be used as the reducing agent in the blast furnace
in place of coke. The process of waste plastic utilization is very simple, waste plastics
are pulverized and granulated, and then injected into the blast furnace (Similar like coal
dust injection.) through the tuyeres. The injected plastics are decomposed into Carbon
mono oxide and Hydrogen, both of which act as reducing agents for converting iron ore
into iron. As H2 is used in the reducing reaction in addition to CO, approximately 30%
less CO2 is generated than when the blast furnace is operated slowly by coke. Normally
60% of the plastics injected into the furnace are consumed for reduction of Iron ore. The
gas generated by the remaining 40% of the plastics is used as fuel gas. Plastics such
as PVC (Polyvinyl chloride) can not be used in the blast furnace without de-chlorination.
Solid plastics such as plastics bottles are pulverized into designated sizes by the
pulverizer and directly injected into the blast furnace. The film plastics are pulverized
and granulated into designated sizes by the granulator before being injected into the
blast furnace. Means all kind of waste plastics like electrical appliances, communication
equipment, auto markers, machine components plastic waste of chemical companion,
domestic appliances. In India there is now waste of mineral water bottles – which will
some as principle plastic waste for such purpose. In Japan – Ohgishima and Fukuyama
plants has tie up with municipal corporations of major metropolitan country for supply of
waste plastics. In this recycling system, consumers are required to selectively discard
waste plastic containers and packaging which are then collected separately, stored in
accordance with designated sorting criteria and sorted by municipalities. Each municipal
– has got contracts with above two plants.

Process In Blast Furnace
      The process of converting domestic waste plastics to blast furnace fled material
has been shown in fig No 1. The Bales of waste plastics are fist taken to ballistic
separator for separating into solid plastics and film plastics. Solid plastics such as
plastic bottles are then placed on the manual sorting line for removing impurities, and
pulverized into designated sizes by the pulverizer, and injected into the blast furnace as
the reducing agent film plastics are pulverized into designated sizes by the pulverizer,
and charged into the specific gravity separator for PVC removal by using the difference
in specific gravity. After PVC removal, the pulverized film plastics are granulated into
designated sizes by the granulator before being fed into the blast furnace. The amount
of plastic injected into the blast furnace will replace 11/2 times of the coke requirement,
which means by great extend blast furnace coke shortage problem can be over come.
Business Opportunities in Waste Reuse in Iron & Steel Industry                     [4.3 / 4 ]


Specially in the developing countries like India, when not sufficient presence of coking
coal is existing.




   Fig. No.-1, Schematic flow for converting domestic waste plastics to Blast Furnace
                                        Material

Recycling of waste PET bottles
      Several companies in the world have started the business of recycling waste PET
bottles since 1990 PET bottles are widely used as contains for soft drinks, soy sauce,
mineral water, eatable Oil, other for example domestic consumption of PET bottles in
Japan is increasing each year and reached almost 70,0000 tons in 2005, of which about
270000 tons were collected by municipalities. The process flow treating waste PET
bottle has been shown in fig no. 2, Based on keihin works. This plant processes
transparent waste PET bottles into PET resin flaken. Waste PET bottles collected by
municipalities contain coloured bottles, caps and label. The most important issue in this
operation is how to remove these foreign objects efficiently and accurately. For sorting
purpose, combination of mechanical sorting, manual sorting, automatic bottle sorting
and label and cap separation equipment are used. After removal of foreign object, the
waste plastic is processed as per chart and part of this as per pre-design action injected
in the blast furnace as substitution of coke. Similar pattern recycling and utilization of
used electrical appliances is also done as per fig No 3. The major features of used
electrical appliances recycling is that most of recovered materials can effectively used in
Iron and steel industries as being done in Japan’s keihin works. Its unique advantage is
that the recovered plastics, which account for nearly 30% of home electrical appliances,
are directly used in the blast furnace waste plastic feeling operation.
Business Opportunities in Waste Reuse in Iron & Steel Industry                      [4.3 / 5 ]


Waste Plastics Recycling Process Using Coke Ovens
      The most suited process of recycling plastic waste of the blast furnace is coke
oven, In coke ovens waste plastics can be converted into chemical raw material. The
process has been shown in figure No 4. In coke ovens, coal charged into coke oven
chambers is carbonized at a temperature of about 1,1000 C in a reducing atmosphere
and is converted into products, namely coke, tar, light oil and coke oven gas etc. At the
exit from ascension pipes at the top of the ovens, ammonia liquor is used for flushing
high temperature gas generated in the chambers through the carbonization, and the gas
is cooled quickly to about 800c or less. Then the gas is cooled in a primary gas cooler to
about 350 c, where conversation liquid is separated into tar and ammonia liquor at a tar
decanter.
       The carbonization condition in the coke ovens are considered suitable for the
recycling of waste plastics because charged plastics decompose easily at high
temperature in a reducing atmosphere.




             Fig. No.-2, Schematic flow of the recycling for waste PET bottles.




         Fig. No.-3, Schematic flow of recycling used home electrical appliances.
Business Opportunities in Waste Reuse in Iron & Steel Industry                                 [4.3 / 6 ]


Waste Plastics Recycling Process Using Coke Ovens
      The Najoja and Kimitsu works of Japan commercially using waste plastic in coke –
ovens since 2000.In above plants a test of processing general waste of plastic container
and packages (The analysis results of which are shown in table 3 & 4) using
commercial coke ovens. The yields from the carbonization of the general waste plastics
at the test were 20% of coke, 40% of tar and light oil and 40% of gases, approximately.
(See fig. no. – 3)


Table No. 3 : Ultimate analysis and Ash content of waste plastics.
 Ultimate analysis (mass % day)                                                Ash (mass % )
       C              H               N                  S
     72.6            9.2             0.3                0.04            -              5.0

Table No. – 4 : Component of waste plastics
                                          Component (mass %)
      PE             PS             PP            PVC            PVDC         PET            Others
     21.4           24.8           13.7            52            0.4          15.5            19.0


Influence of waste plastics Addition on coke quality




                                Fig. No.-4, Coke making process




                       Fig. No.-5                                       Fig. No.-6
Business Opportunities in Waste Reuse in Iron & Steel Industry                     [4.3 / 7 ]


      To evaluate the performance of waste plastic addition in coke oven, on coke
quality, some test in commercial coke oven. The coke strength in the case that general
waste plastics after a volume reduction treatment is added to coal by 1 mass%. The
coke strength was evaluated in terms of drum index (DI), which indicates, the coke
strength at the room temperature and CSR which indicates the coke strength after high
temperature reactions. The result with 1 mass% waste plastics addition, coke strength
remains unchanged. This has been shown in fig. 5 & 6.




                         Fig No.7 Conversation rate of waste plastics
     For example the annual consumption of coking coal of the Japanese steel industry
is about 50mt. If waste plastics are to be added to the coal charge by 1 mass%, the
waste plastics consumption will be about 5 lakhs t/y in coke oven along and this will be
a energy saving.




     Process : Fig No. 8 shown the process flow of the waste plastic recycling by the
coke oven from waste plastics to chemical raw materials method. After waste plastic
containers and packaging are pre treated for crushing, removal of foreign matters and
briquetting, they are mixed with blended coal, charged into coke ovens, and
decomposed at 12000C at the maximum without oxygen supply to yield 20% of coke,
40% of tar and light oil and 40% COG (a Hydrogen – rich gas), approximately. The
collected material is used as a chemical raw material. The recovered coke is used to
reduce the iron ore in a Blast furnace, the tar and light oil are used as raw materials for
Business Opportunities in Waste Reuse in Iron & Steel Industry                        [4.3 / 8 ]


plastics etc. and the COG gas is used at power plant etc. as a clean energy source. The
waste plastics recycling by the coke oven from waste plastics to chemical raw material
method is most popular in Japan and many steel plants has adopted. These methods of
plastic recycling to reduce the energy consumption in Iron and steel plants.

Conclusion
     Many parts of the world business development and R&D activities on resource
recycling were outlined many steel plants. Recycling business are making the best use
of the advantage of etc steel works located in the urban area, where huge accounts of
industrial and municipal wastes are generated. Thus providely the steel works with new
social value. Existing facilities are being effectively used to turn waste into Iron and steel
making material. The future shortage of coking coal effectively can be solve by use of
waste plastics in blast furnace and in coke oven.

				
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