Asbestos

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					Asbestos
                 Asbestos
► Certain minerals   that have a fibrous habit
                     Asbestos
► Uses?
     Insulation
     Fireproofing materials
     Brake and clutch linings
     Construction materials
     Filters
     etc
                  Asbestos
► Today’s   lab
   This will reinforce optical skills
   Show you how understanding mineralogy can
    be important to public health and current issues
                                Asbestos
           varies depending on the
► Definition
 organization:

   Mineralogist- fibrous material with a length
    width ration of at least 10:1


   OSHA(                   ): a mineral material
          Occupational Safety and Health Administration


    composed of any of the six silicate minerals
    (table 1) with a length width ration of 3:1
                    Asbestos
► Riebeckite   – crocidolite (blue) amphibole

► Grunerite   – Amosite (brown) amphibole

► Actinolite/Tremolite   – Byssolite amphibole
   You have seen this in lab before
► Serpentine –    Chrysotile (white) sheet silicate
                       Asbestos
► Serpentine (white)
   It is a sheet silicate, how is it fibrous?
     ►Two   sheets make up this silicate
         Mg2+ (9.36 A)
         Si4+ (9.05 A)

         These two share an Oxygen in their bonding
         This causes the chrysotile to form in tightly rolled sheets
          that make long flexible fibers.
            ► Seen only in HRTEM
            ► Figure 1
Chrysotile Atomic Structure




                       Image Used
                       from:
                       http://www.ehponline.org/
                       members/1997/Suppl-
                       5/fubinifig4.GIF
                  Asbestos
► Check   out the hand samples in the room
   (away from the TA…safety is an issue here)
   DO NOT open the bags. The bags are around
    the mineral for a reason…and it’s not to keep
    it fresh for you to smell.
                            Asbestos
►   Microscope
     A
     B
     C
        ► When trying to determine which Asbestos these thin sections
         represent choose
            Crocidolite, Amosite, or Chrysotile
               ► More properties can be noted in the handout
               ► These properties will more than likely show up on the
                 next great Quest
►   Stereo Microscope (larger & more generalized view)
      Amosite, Crocidolite, and Chrysotile
        ► Match   these to the thin sections & sketch them in the second
         circle
                   Lab Cont.
► This lab is designed with dual work sessions in
  mind. You will do your part here and you will do
  the take home component.
► TURN IN the take home portion at or by the start
  of next lab for credit. Otherwise a late penalty will
  be assessed.
► This isn’t a tough lab. I expect the in lab portion
  as well as the take home portion to be neat and
  well done. The take home portion is to be
  typed in a word processor and printed to
  hardcopy.

				
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posted:12/19/2011
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