Document MLQ8YKdRxKkbq28B1k2Jbp8L

PRODUCED BY FORD i ii I i i i 60 Asbestos Fv.sdahkntais ' with increasing degree of dispersion or rising fineness (0.5 g > 190 mesh per end Al. 40 Mil: *15 g < 9400 mesh per cm'A 3.05 MR). Although the magnetite n mponent is of significance chiefly in the chryse*ilr. the mogneti'*- content and MR-vnIues of ail varieties of asbestos have been included in Table 5. In line with their nnsle of formation and place of origin, the ^ _ ( 'low-iron" chrysotiles are frequently accompanied by carbonates " (dolomite, calcite, etc.), so in determining the composition, there fore, it is neccssaiy to take into account the amount of CnO (calcite) and/or MgO (dolomite) required to bind the found C0, and these amounts must then be subtracted from the total amounts of CaO or MgO found. The chemical investigation of samples of asbestos is likewise made more difficult by the need for analyti cally separating Ca, Mg, Fe, and Al, as well as by the necessity of determining the quantities of alkali metals present. These steps make it more difficult to obtain reproducible results and they also complicate the assessment or interpretation of the analytical findings or the calculation of the formula of the specimen -- an operation that requires a knowledge of the complicated relation ships and some experience in this field. Of course an empirical formula can be set up for each asbestos on the basis of the found percentage composition. Such formulas often show the proportion of the individual ions (elements or substituents) in the molecule expressed in decimals. For example, the anthophyllite asbestos of the Bresimo Valley (Ortler group. Upper Italy) has been represented as being: (Co.No^)aJ0(AI,Ti,Fe3%Fe^Mn>19)#.7J(Si,AI),.>(0H),,JO,,w Although such empirical formulas have proved of value for certain industrial purposes, it nonetheless is difficult to decide which portions of the analytical findings should be included in the form ula. , LITERATURE 1. W. E. 8ine!atr, Asbestos and its associated minerals, Aibcetoi 40, No 13-10 (1958). 2. Idem, Amasitc-Montasite, the unique forms of amphiboie asbestos, ibid., 38, No. 0:2-13 (1957). '3. O. Bowies, Utilization and availability of asbestos in etcctrical insulation, Admfo 36, No. 2:3-18 (1954). 4. W. E. Sinclair, Chrysolite asbestos in serpentinized sedimentary deposits, Admlot 39, No. 12-12 (1957). Properties or Asbestos 61 5. M. C. Shaw, Asbestos Tcxtite Institute, New Jersey, Ceramic Research Station, Rutgers University, New Brunswick, Report No. 29 of June 10, 1954. 6. M. S. Badotlet nnd N. VC, Edgerton. Properties of asbestos fillers imported into the United States, Tram. fan. fast. Mining Mr*., 03:10.15 (1900). 7. A. Viswanthan and M. C. Suryoranmn, On the iodimetrie estimation of bivalent iron, J. Indian Chem. Sac., 29, No. 0:403-01 (1952). 8. M. B. Stschigai ami II. B. Burtschinskaja, Determination of trivalent iroo with tetraborate, /. nnntijt. Chem. (Moscow), 7, No. 5:289-300 (1952'. 9. S. Kallmann, Dcterminntion of sodium and potassium in silicates, Ind. Eng. Chem. Anal. Ed,, 18, 678-80 (1940). 10. C. Yaasilev, Methods for determining alkali metals in silicates with lire aid of Ume, Leichtind. (Sofia), 2, No. 1025 (1953). 11. J. Navarro, Determination of calcium and magnesium with Complcxon III, Afinidad, 30:256-57 (1953). 12. B. L. Ingram and L. Bean, Removal of manganese prior to calcium and magnesium precipitations, Anntgt. Chem., 25:1217-19 (1953). 13. H. Ft'.a u. F. Huditz, Die Schnellhestimmung dcs Calciums in Magnesit*-' i'tdex-Rdtch., No. 4:181-85 (1952). 14. O. Crane u. A. Zohtcr, Schnellhestimmung von Calcium und Magnesium in Erzen und Schlaeken, .4/tprir. Chem., 65, No. 21:523-53-3 (1953). 15. W. M. Hazel and IV. K. Egtof, Determination of calcium in magnesite and fused magnesia, Ind. Eng. Chtm. Anal. Ed., 18:759-60 (1946). 16. E. R. Wright and R. H. Dciaune, Separation of calcium from magnesium by the oxalate method in samples of high magnesium-calcium ratio, Ind. Eng. Chem. Anal. Ed., 18:426-29 (1910). 17. R. Pirani, The Minerals of the Ortler gronp. Alii Acad. not. Lincei, Rend., Cl Sei. Fis. Mat. Nat., 13:83-88 (1952). 18. H. Woodratachek, Orientierte Vetwaehsungen von Chrysotil mit MineraBen der Serpentin-Gruppe und mit Kalzit, .Yene* Jahrb. Mineratog., Monarch., No. 6:135-40 (1957). 9.3 Fibers: Classification, standardization, disintegration The various kinds of asbestos are subdivided, treated, and used in' accord with the length of their fiber and their degree of dis integration, and consequently these characteristics are among the most important properties of the asbestoses. Among the crossfiber deposits of all varieties of asbestos, a distinction is made fundamentally between the hnnd-selccted crude asbestos ntid the mill fibers; both principal groups nre further subdivided on the basis of length of fiber into ctasscs and subclasses nnd then again according to their degree of disintegration or texture of filter. For the sake of uniformity nnd simplification of the method of notation, properties, processing, and uses, the classification of the asbestoses has been partially standardized or accepted as binding