SOAPSTONE IN RAJASTHAN INTRODUCTION Soap stone, Talc and Steatite are the ,three different terms used for one and the same mineral. The term talc refers ideally to a very pure hydrous magnesium silicate (3 MgO Si02H2O) which has a theoretical chemical composition of 63.5% Si02, 31.7% MgO and 4.8% H2O. Soapstone is a massive, soft, greenish talcose rock which is a mixture of talc and various other magnesium silicates. Steatite (some times termed lava talc) is a compact, massive talcose rock with no visible grains. The inferior and hard variety of soapstone is called Potstone. Talc is an alteration product of original or secondary magnesium minerals or rocks resulting from mild hydrothermal metamorphism, perhaps aided by mild dynamic metamorphism. Talc deposits are generally associated with carbonate rocks having higher magnesia content like dolomite and magnesite, and rarely with marble & limestone. Contact zones of basic and ultrabasic intrusives also serve as good locales for talc deposits. The occurrences of talc are widely distributed in the country in Andhra Pradesh, Bihar, Gujrat, Karnataka, Madhya Pradesh, Maharashtra, Orissa, Tamil Nadu, Rajasthan & Uttarpradesh. However at present the exploitation of the mineral is confined to Anantapur, Chittor & Cuddapah districts of Andhra Pradesh; Hazaribagh and Singhbhum districts of Bihar, Sabarkantha district of Gujarat, Jabalpur and Narasingpur districts of Madhya Pradesh, Bhandara district of Maharashtra ; Ajmer , Alwar, Karauli, Sirohi, Sikar, Rajsamand, Udaipur, Dausa, Banswara, Dungarpur, Jaipur and Bhilwara, districts of Rajasthan; and Almora & Pithoragarh districts of Uttar Pradesh. OCCURRENCE IN RAJASTHAN Rajasthan is the leading producer of Soapstone in the country. There are 335 mining leases for soapstone in the state and about 525160 tonnes was produced during the year 1997. The description of the deposits in Rajasthan is given below. RAJSAMAND DISTRICT Usan-Kagmadar-Sangat-Kalora- Rabcha-Oden belt This belt runs from Usan in SW to Oden in NE over a strike length of 29 kms. The soapstone mineralization is distributed in two distinct zones and is associated with dolomitic limestone of Aravalli age and quartzites of Pre-Aravalli age. Soapstone occurs as lenses and lenticular pockets of varying thickness and sizes, usually ranging between 1 to 5 mts. in width and 10-15 mts in length. Generally it is reddish white to white in colour. The inferred reserves are 0.890 million tonnes. The important working deposits in this belt are Usan, Gorach, Kalora, Rabcha and Unwas. UDAIPUR DISTRICT (i) Orda- Deopura-Dingri-Nathara-ki-Pal belt This belt is about 40 km. SE of Udaipur and runs from Orda-Deopura to Nathara-ki-Pal over a distance of 12 kms. Here soapstone is associated with talcose schist and dolomitic limestone of Aravalli age. The soapstone is found to occur as lenses and veins varying in length from 18 to 90 metres and in thickness from 2 to 15m. The soapstone is massive as well as foliated in nature and having white to pale green colour. Inferred reserves are 0.5 million tonnes. (ii) Salumber- Bend-Sajela- Lohangi-Pandla- Deola belt This is the most important belt which runs from Salumber in NW to Deola in SE over a strike lengh of 40 km. The soapstone mineralisation is confined to dolomitic lime stone belonging to Aravalli age. Soapstone mineralisation is in the form of lenses and lenticular veinsextending in length from 100 to 400 m. and in width from 0.2 to 25 m. The soapstone is generally of very good quality having pure white to light green colour. Inferred reserves are 0.99 million tonnes. (iii) Undithal-Rathora-ka-Gurha-Bansra-Jharol belt This belt extends from Undithal in SE to Jharol in SW over a distance of 34 km. The soapstone is associated with Post Aravalli ultrabasic intrusives. Soapstone occurs as swelling & pinching irreqular veins & lenses. varying in length from 7 to 48 m. and in thickness from 0.5 to 8 m. The inferred reserves are 0.536 million tonnes. (iv) Rikhabdeo - Chiklan- Khojawara Mundwara - Chhani belt This belt runs from Rikhabdeo in NW to Channi in SE over a length of 25 km. The soapstone is associated with Post-Aravalli ultrabasic intrusives and occurs as irregular leases and veins varying in length from 30 to 100 mts and width from 1 to 3 m . It is of Pale green to greenish-white colour and is normally massive. The inferred reserves are 0.570 million tonnes. (v) Rikhabdeo-Kagdar- Kalyanpur belt This belt runs from Rikhabdeo in SE to Kalyanpur in SW over a 20 km. length. The soapstone is associated with Post Aravalli ultrabasic intrusives. The mineralisation exhibits pinching and swelling tendency. The soapstone is of flaky type varying in colour from pale green to greenish white. The inferred reserves are 0.654 million tonnes. DAUSA DISTRICT In Dausa district the soapstone deposits are located. at Degota, Jharna, Kalajpuri Raylala, Dhaniawara and Geejgarh-Ranoli Achalpur areas. The soapstone deposits at Degota- Jharna, Kalajpuri, Dhaniawara and Rayala are associated with dolomitic limestone belonging to Railo Group of Delhi Supergroup. The soapstone occurs in the form of lenses and veins. The talc bodies in many cases are thin near the surface and widen at depth. The thickness varies from 1 mt to 6,mt. and persists beyond the excavated depth of 25 mts. The Jharna mines are open cast where as Degota mine is a underground mine in which working ,has reached to 140 metres depth. Talc is pale greenish to light green and white in colour and foliated. The inferred reserves of 9.2 million tonnes of soapstone have been reported from DegotaJharna belt. AJMER DISTRICT The soapstone occurrences are found near villages Hahmdi, Gegal Akhari, Lachipura Sendra, Chitar and Chapaid. The soapstone in the area is associated with talcchlorite schist, an altered product of basic intrusives within the quartzite, phyllite and garnetiferous mica schist belonging to Ajabgarh group of Delhi Supergroup. Soapstone occurs as thin veins/lenses in an en-echelon pattern with in the talc-chlorite schist. The thickness of individual veins vary from a few centimetres to about a metre. The soapstone mined from the area is mostly of DDT grade. ALWAR DISTRICT The soapstone deposits in Alwar district are located at Ratangarh, Nagalheri, Baisawas and at Bhugarbha. The soapstone occurrences are confind to limestone or dolomitic limestone belonging to Railo Group. The soapstone occurs mainly as veins, lenses or lenticular pockets of varying dimensions. The veins vary in thickness from few centimetres to one mt. The soapstone is mostly of paper grade. BANSWARA DISTRICT The Soapstone mineralization is spread around Jagpura, Tartai, Bhukia, Mewal, Kundali, Kondri, Duduka, Mandela jamboi, Himmat Singh ka-Gurha and Rhaniya area. It is associated with the rocks of Aravalli and Delhi Supergroup represented by dolomitic limestone, ultrabasic and talc-chlorite schist. It occurs as narrow veins ranging in thickness from few centimetres to 2 metres. Soapstone is foliated to massive and is generally white, Pale green, greenish white and dull grey in colour. The talc produced from the area is reported to be of cosmetic grade. About 0.27 million tonnes of reserves have ben estimated from these areas. BHARATPUR DISTRICT Soapstone mineralization is located near village Nidar ( teh. Bayana), Mangren (feh. Ber), Bilung (teh. Kama ). The soapstone is of low grade. CHITTORGARH DISTRICT In Chittorgarh district soapstone occurrences are reported near village Chiklar (Teh. Pratapgarh) and Sukhadia (Teh. Dungla). DUNGARPUR DISTRICT The important deposits of soapstone are located in a 35 kIn. long belt from NNW of Rikhabdeo to SSE of Dungarpur near village Deval, Balwara, Thana, Piploda, Deopur, Panchpura & Bodawali etc. The soapstone deposit$ are mainly associated with serpentinites and dolomites along fractures and shearzones as small and large lenticular patches, elongated bodies and thin narrow impersistant bands. The individual veins have been found to continue over a strike length of nearly 50 mts. down to a maximum depth of 20 mts. In the area 60% of the material is talc grade. 30% paper grade and only 10% is D.D.T. grade. JHUNJHUNU DISTRICT In the district occurrences of soapstone are reported from Dhani (teh. Khetri) Gudha and Kho area (Teh. Udaipur wati) KARAULI DISTRICT The soapstone in the district occurs in Morra-ka-Dungar ridge of Toda Bhim tehsil. It is located 27 km. North-West of Hindaun, situated on the NagdaMathura broad gauge section of the W.R. Talc deposits in the Morra-ka-Dungar ridge are known for the last 125 years and these have been worked on a small scale ever since. Between the village of Dhaota and Morra which are about 8 kIn. apart the talc deposits have been exposed at as many as seven localities near Dhaola, Dwain, Kamalpura, Rajuli, Giarhi, Pura & Mora. Of there the deposits of Dwain, Rajauliand Gorhiare fairly large. Most of the depo$its in this area occur in the basal part of the massive quartzite (Alwar group) The talc occurs in lenses which vary in width from less than a metre to 20 metres and are exposed over lengths varying from a few metres to 40 metres. The talc is generally pale to light green and pale greenish white in colour, cleaved to locally compact & massive. The 'indicated' reserves of talc from Dwain Rajauli & Garhi areas have been estimated at about 0.107 million tonnes for depth varying from 8m to 30m. along dip. BHILWARA DISTRICT The soapstone deposits in Bhilwara district are one of the bestgrade and are located at Ghevaria, Chainpura, Kishangarh Bagwara, Asanmata, Bhilaikheda, Kacholia, Amargarh, Chhabria, Abhaipur, Bhunagar and near Jahajpur. The Ghevaria soapstone deposit in the single largest deposit in the country which is estimated to contain 20 million tonnes of reserves. The soapstone occurrences in this district are confined to dolomitic limestone/quartzite belonging to PreAravali Group. Two parallel ridges of dolomitic limestone extend from Ghevaria in the south west up to Jahazpur in the north east for a distance of more than 32 kIn. All the important deposits of soapstone in this area are located on these ridges. The soapstone occurs mainly as veins, lenses and lenticular pockets of varying dimensions. The soapstone is generally of pale greenish to light green in colour. Near surface it is off-colour and stained yellow and red but at depth quality improves and it is free from ferruginous materials. TONK DISTRICT In Tonk district soapstone has been reported from Chandsen and Ghati (feh. Malpura) and Niwai village. PALl DISTRICT In this district soapstone is associated with asbestos in ultrabasic rocks near village manpur and Kanotia in Tehsil Raipur. USES Talc is used mostly in a fine-ground state although soapstone is used in massive or block form. There are many industrial applications for ground talc but major consumption is limited to less than a dozen industries. Talc is used as a filler material in the manufacture of high quality paper where it aids in dehydration of the pulp, improves characteristics, reduces the tendency of papers to yellow and assures a well bonded surface to promote ease of printing. For use in the paper industry talc must be free of chemically active compounds, have a high reflectance, possess high retention characteristics in the pulp and be free of abrasive impurities. Micronized materialprovides a high-gloss finish on coated papers. The ceramic industry utilizes very finely ground talc which increases the translucence and toughness of the finished product and aids in promoting crack-free glazing . For use in ceramics, talc must be free of impurities which would discolour the fired product. High- quality talc is used as an extender pigment in paints. Specifications for a talc pigment, relate in the chemical composition colour, particle size oil absorption and consistency of and dispersion. A low content of carbonates , a nearly white colour, a fine particle size with controlled particle size distribution and a specific oil absorption are important, however, because of the variety of paints precise specifications for talc pigments are generally based on agreement between consumer and supplier, paint characteristics influenced by the use of talc as an extender are gloss, adhesion, flow, hardness and hiding power. Talc is well known for its use in pharmaceutical preparations and cosmetics. It is the major ingredient in face, baby and body powders. Finely ground, high-purity material is used as a filler in tablets and as an additive in medical paste, creams and soaps. Material used for these purpose should be free of deleterious chemical compounds and abrasive impurities. Lower grade talc is used as a dusting agent for asphalt roofing and gypsum board, as a filler in dry wall sealing compounds, as a filler material in floor tiles, in asphalt pipeline enamels, in auto body patching compounds, as a carrier for insecticides and as a filler or dusting compound in the manufacture of rubber products. Other application for talc include use in cleaning compounds, polishes, electrical cable coating, plastic products, foundry facings, adhesives, linoleum textile, and in the food industry. Particle size specifications for most uses require the talc to be (-)325 mesh. The paint industry demand from 99.8 to 100 %, (-)325 mesh. For rubber, ceramics, insecticides and pipeline enamels, 95 percent, (-) 325 mesh is usual. In the wall tile industry 91 per cent ,(-)325 mesh is generally required. For roofing grades the specification is about (-)80 mesh with a maximum of 30 to 40 percent, minus 200. Soapstone has now only very limited use as a refractory brick or block, but because of its softness and resistance to heat it is still used by metalworkers as marking crayons. The case with which it can be carved makes it an excellent artistic medium..
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