Document wjd1ZYmmyBMZ78YEm3ZoX04o

PRODUCED BY FORD ;hanged, probably for three reaaona: the need for insulation for the new steam technology, the formation of an International trading company of Italian and English entrepreneurs, and the reopening of the chryaotlAe isbestos deposits of northern Italy and simultaneous exploitation of the /set chrysotlle resources In Quebe'fc. The supply for the first tine was nnple, and the market was ready. fhe modern Industry The reopening of the asbestos deposits of northern Italy, deposits hlch had previously been worked as far back as Roman times, serves to sark the beginning of the modern asbestos Industry. The Italian asbestos ns unusually silky and long flbered^ and thus readily woven Into tex tiles. The shrouds and cloths of antiquity may have been made from this isbestos. By 1890 the modern asbestos Industry was full blown, with hundreds jf applications being Introduced (Jones, 1890){ by the turn of the cen tury the large South African erocldollte deposits had been opened up, and the Russian deposits In the Urals were once again producing In large quantity. Vithln a few years, the smoelte deposits of the Transvaal soold be exploited. - From the time of the first recorded use of asbestos by Stone Age mn to 1900, the total world production of all types of fiber was prob ably about 200,000 metric tonnes, certainly no more than 300,000 tonnes. 01 this, 150,000 tonnes cane from Quebec. By 1980 over 100 million tonnes of asbestos had been mined throughout the world: of this over 90 percent was chrysotlle and over 5 percent erocldollte and amoslte. Total produc tion of anthophylllte asbestos to date Is probably no more than *00,000 tonnes, 350,000 tonnes being produced by Finland alone. Production of trcmollte asbestos has been sporadic: It was mined In various parts of the world for short periods of time. Totsl production to date for this 3Two samples of Italian asbestos on deposit at the U.S. Rational Museum are both chrysotlle. One. U.S.R.M. Ro. 73539. Is from "Piedmonts, Italy*, and was acquired by the museum In 1900 from the Isaac Lea Collec tion. The fibers In this sample are up to 120 cm longl The second sam ple, U.S.R.M. So. R3172 (Roebllng Collection) Is from Val Malenco, Sondrlo, Lombardia, Italy. Fibers are up to 15 cm long In this speci men. 286 8005 0054 Torn of sabestos Is probably no more than a few thousand tomics. Cob* merclal exploitation of aetlnollte asbestos la practically unknown. The world asbestos production for 1978 Is given In Table 3. Russia leads with *6.1 percent and Canada 4k'second with 28.9 percent of the world output. Both countries mine only chrysotlle asbestos, and most of the fiber comes from the Urals and Quebec.. The third leading asbestos producer la the Republic of South Africa (7.1 percent): the asbestos ore consists of amoslte, erocldollte, and chrysotlle. These three countries furnished 82.1 percent of the world's asbestos In 1978. The other coun tries listed In Table 3 produce mostly chrysotlle. Modern asbestos uses As alluded to before, heat Insulation was one of the most Important uses of asbestos during the early beginnings of the modem Industry; apparently the first application for this purpose was In 1866 (Bowles, 1937, p. 9). The principal uses of asbestos In the United States In 1978 In order of Importance were as follows: In cement pipe (145,800 metric tonnes). In flooring products (122,400), In friction materials (81,600), In roofing products (58,300), In asbestos cement sheet (29,200), In coatings and compounds (29,100), In paper (29,100), In packings and gaskets (23,300), and in Insulation (14,300) (Clifton, 1979). MAJOR CEOLOCICAL OCCURRENCES OF AMPR1B0LE ASBESTOS There are many minerals, ineluding the amphlboles and chrysotlle, that are described variously as fibrous, asbestlforn, acleular, filiform, and prismatic, terms which suggest an elongate habit. Although such minerals are extremely coemon. In only relatively few places do they obtain sultoblo physical and chemical properties to be valuable as com mercial asbestos. Locally, amphlbole minerals may show an asbestlform habit, for example In vein fillings and In areas of secondary alteration, but usually they do not appear In sufficient quantity to be profitably exploited. Deposits of commercial asbestos are found in four types of rocks: (1) banded Ironstones (amoslte and erocldollte), (2) alplne-type ultramafic rocks,, including ophlolltee (anthophylllte, tremollte, and chryaotlle), (3) stratiform ultramafle Intrusions (eremollts and chrysotlle). 287