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*> c rh .ri.ra.i. i i n ..fr. BUREAU OF WINES k Reprint from BULLETIN 650 l ? I l fr f VLt- ASBESTOS J a chapter from mineral facts anti-problems, 1970 edition > * i V * < $ UNITED STATES DEPARTMENT OF THE INTERIOR t ASBESTOS By Timothy C May 1 xnd Richard W. Lewis > The United States is the world's-largest con sumer o( asbestos, using more than one-fifth o( the 3.5 million short tons1 of world production in 1968. The major use for asbestos is in con struction. including cement products. Boor tile, paper products, painu, and caulking. Approxi mately 15 percent of U.5. asbestos requirements are ootained from domestic production and 85 percent from imports. Canada provides about 80 percent of the asbestos imports and the Republic of South Africa most of the rest. The South Afrian material consists largely .of the special amo> site and crocidolite varieties of asbestos; the other sources supply predominantly the more common chrysolite variety. Domestic demand for asbestos for the year 2000 has been forecast in a range of 1.28 to 1.87 million tons. The main uses of asbestos are expected to remain in the construction materials. The major contin gency which is expected to lead to the high of the range is a broadening of the use of asbestos in cement products. The low is based on the uses of substitutable iower cost materials particularly in the areas of ceramio and new plasties. The developing countries are becoming more important consumers of asbestos products. The necessity of low-cost housing is considered the principal factor, since asbestos cement is well suited for use in hoc and humid countries. At the forecast rates of consumption, there are ade quate sources of asbestos to meet the U.S. and rest-o(-the-world demands to the year 2000, but shifts in supply centers may take place. Canada is expected to eontinue as the leading free world producer, but output from other countries should become increasingly significant. In the United States the demand for asbestos fiber requirements is changing, and the substan tial California deposits could reduce the reli ance on imports by the year 2000, provided that products from the relatively short fiber receive consumer acceptance. A more remote possibility (or a new supply source would be the develop ment of synthetic asbestos production resulting from research in that field by both Government and industry. Health hazards are present in tbe entire se quence of extracting, processing, and in some cases even consuming asbestos fibers. Medical re search into all aspects of health problems related to the mining and use of asbestos is being per formed and should alleviate the problem by the year 2000. BACKGROUND INDUSTRY PATTERN The Province of Quebec. Canada, has the largest asbestos mines and mills in the world. The U.S.S.R. rivals Canada as an important producer-The Republic of South Africa. South ern Rhodesia, Swaziland. Italy, and the United States are substantia! producers, and smaller sup plies originate in many countries. The variety chrysotile constitutes about 95 percent of the world suoply, and unless otherwi** designated the data herein relate to chrysotile. Total world production in I96S was estimated at 3.5 million tons of all grades and varieties. Of this total, Canada produced about 46 percent; the U.S.S.R.. 25 percent (estimated); the Repub lic of South Africa. 7 percent; Southern Rho desia. 5 percent; the United States, J percent; and Italy. 3 percent. Most published data on world production of asbestos credit the U.5.S.R. as the largest producer, but Bureau of Mins ttaiisties (77)* indicate that much of the ascribed quantity included low-grade material used for applications such as railway track bal last. This material should not be considered to be asbestos output and accordingly a much lower quantity has been accepted as the most reliable estimate. Prior to 1962 the only large production of as bestos in the United States was from a deposit in Eden and Lowell Townships. Vu. in what is re- > TPthmyitiiorl ftkiThNmeMil iHKRiiiL mt Msiwn!l fa4u limiW). Tl* |A||IK wav* (Af*|hM( Ihw 0*UT VT (Mi vhlrn MMrvitf pccffcc4. IuMhN nvvtUrn n rvfrr m ium it Ur |m */ irlmnrn 41 iM iM *1 Uu Jmhm, til FOSECO 1440 FOS-0&-D000e33645 852 MINERAL FACTS AND PROBLEMS - ------------------ girded **-a-*ouihern fvirmion of the Quebec deposits. In 1963. deposits in the Copperopohs, Coalings. and Napa areas in California began production. Several operators have small chrysolile mines in an area about CO miles long and 25 miles wide in the Salt River and Cherry Creek basins of Ciia County, north of Globe. Aril. Chrysolite deposits are known in Montana, Wyoming. and other States, but production has been negligible. In addition, amphibole asbestos is produced in North Carolina (V-d) . The largest known asbestos deposits in the free world are in an area 75 miles long by 5 or 6 miles wide between Danville and the Chaudiire River Valley, in the Province of Quebec. Can* ada. Eight companies are mining in this area. Six of these are subsidiaries of companies that operate large asbestos products plants in the United States. Asbestos also has been reined con tinuously in northern British Columbia and northern Ontario since the 1950's. In mid-1963 a new mine began operating at Baie Verte in Newfoundland, and in 196S the Clinton Creek mine was opened in Yukon Territory. Canadian . production in 1968 was valued at Cao$210 mil* lion, whereas U.S. production had a sales value of about $10.4 million. The Soviet deposits, situated in the Bajenova district of the Urals, are extensive. The mines and mills are larire. and most of the fiber is used within the U.S.S.R. Southem Rhodesia is an important producer of chrysolite asbestos, particularly in the Sha* bani area. The fiber from these deposits has such a low iron content that it can be made into the excellent electrical insulating material that it re quired in the construction of clccsic. cables for use on shipboard. Most of the other deposits of the world, except the comparatively small ones in Ariiona and the recently discovered large one in British Columbia, have a substantially nigher iron content, making fiber irom them unsuitable for electrical insulation. Swa2iland and the Re public of South Africa also produce chrysotile in - substantial quantities. The Republic of South Africa produces two special types of asbestos-- amosite. found commercially nowhere else, and crocidolitc (blue asbestos), produced also in Australia and Bolivia. Most of the African pro duction is exported (IS). Nine companies with nine operations pro duced asbestos in the United States in 1966. There are four companies in California--Allas Mineral Corp.. Coalinga Asbestos Co.. Ine.. Pa cific Asbestos Corp. (aeouired by J. K.. Porter Co. Inc. in 196S). and Union Carbide Corp.. Nu clear Division. Three companies operate in Ari zona--Jaquayi Mining Corp.. Meiaie Asbestos Corp., arid Western Asbestos Manufacturing Company. Powhatan Mining Co. operates in North Carolina, and General Aniline L Film Corp.. The Ruberoid Division (formerly Ruberoid Co~ VenitbnTAsbestos Mines~Divft;dn)~he" largest producer, operates the Lowell mine near Hyde Park, Vi. Total employment in the domestic asbestos in dustry was ISO in 19GS. consisting of 155 at the mines and 2'JO at the mills. This number has been constant since 1964. Johnt-Manville Corp. is the largest producer of asbestos in Canada and is a fully integrated company. It operates on a worldwide basis and it the price leader in the industry. It owns many consuming plants in the United States. -Turner L N'ewall. Ltd.. Manchester. England, runs a fully integrated operation which operates on a worldwide basis. The company owns mines in Southern Rhodesia, the Republic of South Africa, and Canada. In Canada, it owns Bell As bestos Mines Limited, at Thetford, Quebec, has a large minority interest in Cassiar Asbestos Corp., Ltd., McDamc Lake, British Columbia, and aets as selling agent (or Cassiar. Cape Asbestos Co.. Ltd,, Loudon. England, is a fully integrated operation whose mines are lo cated in the Republic o( South Africa. Manufac ture of asbestos products is carried out in Europe and North America. TECHNOLOGY Definition ul Touts, Guile, auil Speciuctuuiii Asbestos is a name applied to a group o( natu rally fibrous minerals. The principal variety is chrysotile. a hydrous magnesium silicate haring the theoretical formula SMgO.2Si0>.2H.0. Other commercial varieties are amosite. a com plex iron-magnesium silicate. (FeMg) SiO,.l-5 percent H0; and a-oddolite. a sodium-iron hy drous silicate. NaFe (Si0s)^FeSi0a.H>0. Of minor ' importance arc tremolite. Ca.MgjSijO-- (OH),; - and amhophyllitc. (MgFe)rSif~(OH), (2). Chrysotile. the principal variety of commccc. is graded according to fiber length. According to the Canadian dassifieation. fibers three-eighths o! an inch long or longer are classed as a-udes and comprise groups 1. 2. and 3. Crouo 3 is the usual product obtained from the cru^e and is used largely (or spinning fiber. The succeeding groups have progressively shorter fibers. Group 4 is designated as shingle stock; group 5. paper stock: group 6, waste stucco and plaster; and group 7. refuse or shorts. Most of fKese groups are divided into several subgroups. Such groups ings comprise the commerdal specifications. The consumer designates the grade desired. In Ariiona fiber which remains on >/.-ineh screen is classed as No. 1; that which passes 1Ainch mesh and remains on t/-inch mesh. No. 2: that which oasses 1/,-inch mesh and remains on i/i-inch mesh. No. 3; and that which passes t/,- FOSECO 1441 - - rOS-0-0aG3B<.fc ASBESTOS SS3 inch. No. 4. Nos. I and 2 ire classed at spinning grade if the fiber! are not too harsh. Some spinning fiber is obtainable from No. 3. Crades rhry--be--bicnded--to--satisfy- speciil needs. For some uses the chemical composition is important. Thus, for electric insulation an upper limit for the iron foment may be speci fied. The methods of classification used in the principal producing countries are discussed in detail in a Bureau of Mines publication (1). Current Technology Most chrysolite asbestos deposits, including those of Vermont and California. Canada, Southern Rhodesia, Swaziland. the Republic of South Africa, and the U-S.5.R... consist of irregu lar a-oss-fiber veins (closely packed fiber set at a right angle to the faces of the rock fractures) or slip-fiber zones (shear planes in rock filled with fiber matted together parallel to the seam) in massive serpentine. Such deposits commonly extend to unknown depths. Tnosc of Arizona, however, consist of more or leu horizontal asbes tos-bearing serpentine zones in thin-beddedlimestone. Such deposiu are generally leu exten sive and leu persistent than those in mauive ser pentine.- The amosite and crocidolite of the Republic of South Africa occur in banded iron stones that are so folded and contorted that the veins are very irregular. In Vermont, cite fiber-bearing rock is removed from an open pit. Similar methods are employed in the Copperopolis district in California, but in the Coatinga district the highly sheared ute >> simply "plowed" and allowed to air-dry, and the coarse fraction is screened out from the millfeed. The usual practice :n Arizona is to drive a head ing in barren limestone beneath the fiber zone, which is later blasted down and hand-cobbed. The Canadian mines generally are open pits. The dirysotile of Southern Rhodesia, the Re public of South Africa, and Swaziland is ob tained from underground mines. Amosite is obtained chiefiy from large underground workings, and blue asbestos from small open pits and shal low mines. The Soviet deposits are worked both in open pits and underground. Cyprus has large open-pit workings. Asbestos milling is a complex ooeration in volving primarily the separation of fiber from rock ana elauificition of fiber by length into a series of gTades. The operator has little control over the proportions of the various grades, which are fixed in nature, but he has the impor tant task of minimizing fiber damage. He must mill the rock with as little fiber breakage as pos sible. because short fibers are worth much leu than long ones. Special types of rock disintegra tors have been developed, and reduction is ac complished in stages with fiber removal by air suction at each stage. In Arizona the hand-cobbed rock is reduced in jaw crushers, and the fiber is separated by screening. Special milling techniques have been developed for the maned short-fiber chrysoiilc of the Coaiinga afstricr ol Calfforniar'incJadmg-----------grinding and wet-milling processes. In Vermont and Canada the mills are large and complex. The fiber is classified in many grades, sueh as spinning, cement stock, and paper stock. A pressure-packing process is used in many mills, where asbestos fiber is packed under pres sure in five-ply paper bags. Each press-ure^packed bag contains 100 pounds and occupies about 2 cubic feet. Research Research on production has been conducted by companies operating mines in Canada. Sub stantial research has been conducted on utiliza tion of the more plentiful shorter grades in appliations where longer grades arc preferred. For instance, it has been found that more complete fiberization, permitting better contact of cement and fiber, will allow groups 5 and 6 to be blended in increasing proportions with group 4 in making asbestos-cement products. . Two companies have developed processes for reducing the iron content of Quebec asbestos to make it suitable for electrical uses. The JohnsManvilie Corp. manufactures Quinterra paper from such fibers. Raybestos-Manhattazt. Inc. has developed a process for making a low-iron prod uct known as Novabestos. Both Quinterra and ?w>4ueU papers may be iillei lamina led with a fiberglass fabric or grid to give additional strength. These products are now manufactured commercially and are used extensively in cable construction anc for.other nonfen-ous applica tions. The Cape Asbestos Company Ltd.. London, has investigated tensile testing of ooeidolite and amosite, their chemical resistance and their be havior in solutions of various chemicals and sur face active agents. The only laboratory in the world devoted entirely to fundamental research on asbestos fibers was reeentiy constructed by Turner and Kewall Ltd.. .Manchester, England. New types of equipment were developed to sort asbestos fibers according to diameter and length . (") The Naval Research Laboratory has devel oped a Fiberglas gas mask filter said to be supe rior to those made of Bolivian blue asbestos. Bolivian crocidolite is. therefore, no longer re garded as strategic. Much research has been done on the synthesis of asbestos, but results thus far have no commer cial application. The Bureau of -Mines has syn thesized ampnibole asbestos, but the fibers made are weak and brittle. Asbestiiorm compounds not found in nature that have some of the prop- _ -rare FOSECO 1442 .>> jU g54 mineral facts and problems eriics of asbestos have been formed. Chrysotile, the type of asbestos most in demand, has been synthesized in fibers of only submicroscopic ength. The Bureau has performed core drill tests on various properties to determine the oc* cuiTence of asbestos, and the U.5. Geological Survey has studied the geology of asbestos de posits in various states (J-d) . APPARENT RESERVES In Vermont, a reserve of at least 1 million tons of chrysotile fiber appears to be assured. A . small proportion of this quantity is of spinning grade. In California, measured and indicated reserves totaling more than 1 million tons are reported for the Copperopolis area; these re serves consist chiefly of types and grades similar to those in Quebec, Canada. Reserves of several hundred million tons of rock that will yield matted short-fiber chrysotile asbestos are reported for the Coalinga area in California (13). The Arizona reserve is difficult to estimate but is probably small. The world appears to have an adequate asbes tos reserve to meet requirements beyond the year 2000 at current or considerably enlarged rates of outpuL The chief suppliers of U.S. markets-- Canada and the Republic of South Africa--ap pear to have adeouate reserves for long-range planning. .It is di&cult to calculate South Afri can reserves because of the intensive folding en countered in nearly ail the asbestos areas. The duplication of the asbestos ban-ts through fold ing has resulted in large reserves (Jo). The U.S.S.R- reserve is probably large enough to sup ply the Soviet-oriented Eastern European coun tries for many years. SUPPLY-DEMAND RELATIONSHIPS Production, Consumption.' and Trade Most of the asbestos production is chrysotile asbestos, but approximately 200.000 tons of the world's production each year consists of amosite and a'oddoliie. The United States is the largest consumer of asbestos in the world. From 1949 to 1955 the United States consumed on an average about 50 percent of the total world production. Domestic consumption more than doubled from 1945 to 1951, but thereafter it remained fairly constant while world production continued to inarease. In 1966 the United States consumed about 23 percent of the total world production. Domestic sources furnished only a small per centage of U.S. asbestos requirements. Arizona, the only present natural source of low-iron chrysotile in the United Stales, has rarely produced more than 600 tons per year of the spinning grades, ajid the output usually has been consid erably lower. A large part of the production of crudes No. 1. No. 2. and No. 3 was purchased by the U.S. Government for stockpiling from 1953 until the purchase program terminated at the end of 1962. Vermont and the Copperopolis district of Cal ifornia are the ouly consistent U.S. producers of Quebec-type asbestos. Both are predominantly producers of short fiber, but the Vermont asbes tos mines produce about 500 to 700 tons per year of spinning length fiber. Most of it is applied to nonspinning uses. On a tonnage basis Canada furnished 90 per cent of the U.S. imports in 1964-68. but only a small portion (3 percent) -was of the spinning grade. The comparatively small quantities re ceived from Africa are more important than would appear on a tonnage basis, because they consist largely of special kinds and qualities un obtainable elsewhere. Under emergency condi tions imports of spinning fibers are of primary importance. Imports of spinning fibers from Canada average about 17.000 tons per year. The longer fibers of chrysotile suitable for spinning purposes represent a small fraction of tnc total reduction. Shortages of spinning-grade fibm ave occurred. The spinning grades of asbestos produced in Southern Rhodesia were of great importance during Wnrld War II and .the early pssr-rsr years, because they constituted the principal source of low-iron chrysotile suitable for ship board electric-cable construction. Production be gan from a new source of supply of losv-iroa chrysotile in northern British Columbia in 1953, and in 1968 snore than 6,000 tons of these fibers were imported from that source. Production of amosite in the Republic of South Africa has ina'eased from an average of 20.000 tons per year during the 1940's to 90,000 tons in 1966. U.S. imports of amosite averaged about 20,000 tons per year during 1964--68. Part of the imported material has been placed in the national stockpile; hence industrial consump tion has been somewhat lower than the afore mentioned figure. Most crodaolite originates in the Republic of South Africa, where production of croddolite has ina-eased from an annual average of 10.000 tons during the 1940's to almost 180.000 tons in 1968. U.S. imports of ffocidolite advanced from 12.000 tons in 1954 to 24.000 tons in 1966 and dropped to 14-.050 tons in 1968. Conservation The worldwide shortage of asbestos that ex isted during World War II and the early post war period led to wide research and experimen tation on materials that might take its place. To extend and conserve the supply of asbestos fihcrv a glass-asbestos cloth was designed during World Wax 11. It has continued in use as a covering on FOSECO 1443 FOS--00--00000G3Svo ASiESTOi FOSECO1444 " rps-00-00C0e03649 85 5 r ic u u I.--Sn|pCj Demand RcfatfonaMpi fo r Aibctfor. 19SB. ,.->iir^.VMiaBrY 856 M IN'ERAl. FACTS AND PRJ3BL.IMJ thermal insulation appTTed-terpipinron-naval vessels. It is woven with a plied yarn having one siranii each ol glass and asbestos yarn. Some grades of asbestos are more in demand than others. Shortages may develop for the pre ferred grades, and stocks of the less marketable fibers may accumulate. A great deal of research has been devoted to substitution' of the more abundant grades for those that are less plentiful but more in demand. Canadian group 6 fibers have been adapted for use in asbestos-cement products, but groups 4 and 5 are still preferred. BYPRODUCT-COPROD UCT RELATIONSHIPS There are no commercial byproducts in the production and milling of asbestos. The fiber comprises 5 to 10 percent of the rock mined, and the waste rock consists of broken and pulverized serpentine for which very little commercial use has been found. One leading producer has de vised a practical method for recovering magnesia from a waste rock, and a small quantity of by product crushed stone has been marketed. In addition, mill wastes containing appredable asbestos may be usable in producing inexpensive asbestos flooring compositions. CONSUMPTION PATTERN Uses Asbestos is adaptable to more than 2.000 uses. Because of its high strength-to-weight ratio and resistance to searing temperatures it is used in rockets and missiles. Asbestos products plants are located in 16 States, prinripaily in the East and South and on the west coast. ' All uses of asbestos are as processed fiber. The long-fibered groups 1 and 2 are marketed in very small quantities for speaal textile purposes; group 3 is used in the manufacture of fireproof textile products, packings, woven brake linings, clutch facings, elecmical insulation materials, and high-pressure and marine insulation; the major use of group 4 is in asbestos cement pipe which is used mainly in transporting water, such as in municipal waterworks, irrigation, and con servation projects; group 5 is used in asbestos ce ment sheets. Bat and corrugated sheets, low-pres sure asbestos cement pipes and molded products, in some paper products such as pipe insulation and wrappings, and in othv products, including brake linings and gaskets; group 6 it primarily used in asbestos cement products mix, gaskets, brake iiningi, vinyl sheet backings, and mill board; and group 7 is used in molded brake lin ings and clutch tarings. The most important ap plication of "shorts" is as a filler in vinyl and as phalt floor tile, while other important uses are is asphalt compounds, joist and insulation ce- -mertu.-rooL roaiingt^plaiLici_jnd caulking compounds. Amosite is used (or felted insulation in blan ket form lor high-temperature service up to 000s F. A loosely compacted form it used as a covering for marine turbines and jei engines and in similar applications. Amosite is also a constituent of " 65-percent-magnesia insulation and lightweight, flre-resisiant marine*partition board. Long-fiber crocidoliie (blue asbestos) is woven into fa brio used for locomotive boiler lagging in Great Britain and lor acid-resistant packings and gaskets. The principal use of the short eroddolite fibers is in making asbestos-ce ment pipe. Tremolite and anthophyllite are used for chemical-resistant filters, as welding-rod coating, and as fillers in various products. About 69 percent of the asbestos consumed goes into the manufacture of asbestos cement products, about 10 percent in floor tile, 7 percent in asbestos paper. 3 percent into friction mate rials and gaskets, 2 percent in asbestos textiles. 2 percent in paints and caulking. 1 percent in plastics, ana 6 percent in miscellaneous otha' commodities. Alternate Materials Fiberglai is used as a substitute for asbestos in some applications, chiefly in the field of heat insulation, fabrics woven with a plied yarn hav. ing one strand each of glass ana asbestos yarn are advantageous for some uses where light weight and high strength are needed. Glass fila ments are-technically satisfactory substitutes for amosite in blanket insulation, but the cost is greater than that of amosite. Fiberglass not a satisfactory substitute for asbestos in friction materials, asbestos-cement products, and tome of the highly specialized electrical insulation uses. Silicone products, organic compounds, and plastics are used as substitutes in certain limited appliations. The use of calcium silicate, diatomite. and magnesia in some instances reduces asbestos requiremenu in end products. Aluminum sheets are being used as a partial substitute for asbestos where insulation against radiant heat.it required. New types of heat-resistant plastio are being substituted for chrysotile in some forms of electrical insulation. Substantial progress has been made in substitution of Novabestos and Quinterra papers for electrical insulation. There is. however, no. satisfactory complete substitute for strategic grades of chrysotile in some forms of dielectric insulation. Fibrous glass and chrysotile asbestos are sub stitutes for amosite, but they are not as resistant to steam, sea water, and alkalies under all work ing conditions. For 63-percent-magnesia and cal- } FOSECO 1445 FOS-00-000000385G asbestos 657 cium silicate insulation, textile grades of chrysotile stay be substituted for amosite. ECONOMIC FACTORS Prices and Costs Asbestos has had an erratic price history, but since 1965 the price has been quite stable. Prices for Vermont and Canadian asbestos in creased about 5 percent in 1967. Quebec chrysotile fiber prices in 1968, f.o.b. mine, ranged from Can$*5 per ton for 7T. the shortest of the regu lar grades generally produced, to Can5"00 lor the longest of the milled fibers.. Crude No. 1 from British Columbia (Cassiar) sold for Can$I26 to CanSl.522 per ton while other Crude No. 1 from Canada was quoted at CanSMIO per ton. Vermont chrysotile is produced in grades simi lar to those in Canada and ranged in price in 1968 from 5*1.50 per ton for group 7 to 53*2 for group 3, f.o.b. mine. Arizona fibers ranged, in price from $65 per ton for group 7 to SI,650 per ton (or the highest grade No. 1 Crude, f.o.b. Globe, Aril. Prices quoted for amosite, f.o.b. U.S. pom in 1968, ranged from $130 per ton to 5220. Crocidolite- prices tanged from 5180 per ton to 5*70. The total value for the 120,690 tons of asbes tos produced in the United States during 1968 was $10,*06.000 an average of S86.22 per ton. f.o.b. mine. The imports of asbestos tor con sumption t*cic valued at $73 mill-on. The value placed on UJ. demand for 1968 was $79 million. The price plotted in figure 2 was based on the average domestic sales value. Assuming that the proportions of various grades produced remain the same, the price in terms of 1968 constant dollars is expected to increase to $100 per ton by the year 2000. Taxes and Tariffs There are no special taxes on the asbestos in dustry. Producers are granted a depletion allow ance of 23 percent on domestic production and 10 percent on foreign production. Domestic as bestos producers have no tariff protection. Trasssportation _ The Quebec and Vermont deposits are within easy rail haul to most of the planu manufactur ing asbestos products in the industrial areas of the Eastern United 5tates. The African deposits are remote from the principal markets and have high transportation expenses. Transportation from British Columbia is difficult and costly, but a shorter route is in prospect. The Arisona miners have difficult transportation problems; the nearest railhead is at Globe, and the haulage distance from the mines ranges from a few miles Ficuu 2.--Tunt-Avtnje Price AcUlionship tor Albertin. to 10* miles, averaging 50 miles. Futhermort. the major consumption centers are in the North eastern United States, and are much -closer to Quebec, Canada, than to Arizona. Consumption of asbestos is growing along the west coast of the United States, and comparable growth has taken place in other areas where fiber from California would be competitive, in terms of freight rates, with that from Quebec. A 10-percent increase in the ocean freight rates for amosite and croddolite asbestos from the Republic of South Africa to U.S. ports went into effect in 1968. The rate was raised from $27.75 to $30.50 per long ton. Government Programs During World War 11 controls restricted ex ports of asbestos needed in the military program. These controls were removed by executive order cr. September 10, 19*5. During the K.srezn v.'ir the supply situation again became acute, and in 1950 and 1951 controls were invoked that re quired licenses for export of all grades of asbes tos. The license requirement was removed for the nonspinning grades in 1953 and for the spinning fibers in 195*; however, export licenses still are required for shipments to Communist nations. The discovery and development of new asbes tos deposits have long been considered desirable. A program to assist in asbestos exploration was initiated in 1950 with the responsibility vested in the Defense Minerals 'Exploration Adminis tration. The program is now conducted by the Office of Minerals Exploration, and explora tion contracts have been awarded. Three have resulted in certified discoveries. A Government depot in Globe, Ariz.. was opened for the purchase of domestically pro duced asbestos meeting certain specifications. Under Public Law 733 (1956), a Government purchase program at premium prices for domes tic low-iron chrysolite asbestos was established which was terminated on December 31, 1958. In 1959 the stockpile objectives for low-iron chryso lite were raisea, and a barter program was estab lished to acquire the additional fiber needed FOSECO 1446 XL arfS.' Xif-JiA ar'a.-. *''aK<-m> 'jt"r - * - i - sn 858 MINERAL FACTS AND PROBLEMS through exchange of agricultural surpluses. The U.S. Department of the Interior recom mended pnrchajc of 500 ion of low-iron chrysotile from domestic mines to assist the domestic industry and to establish a domestic mobiliialion base for production. Amosite and chrysotile have been acquired (or the stockpile by purchase and barter, and crocidolite hat been acquired by barter. Strategic Considerations Asbestos kinds and grades of greatest strategic importance are being stockpiled. The national stockpile items are spinning-grade chrysotile and atnositc. Bolivian blue erodieoliie is no longer considered strategic. On December 31. 1968, the maximum stockpile objective for chrysotile was 13,700 tons. Government inventories totaled 15.344 tons, of which 6,080 tons was in the na tional (strategic) stockpile, 4.363 tons was in the supplemental stockpile, and 4,881 tons was nonstockpile grade. The stockpile-objective for amosite was 40,000 tons, and inventories totaled 65,311 tons, of which 11,705 was in the national (strategic) stockpile and 53.606 in the supple mental stockpile. The stockpile also contained 48.072 tons of crocidolite that had no objective. The United States is dependent upon foreign sources for sir to si perern! of iu requirements for all grades of asbestos. The principal source of low-iron spinning grade chrysotile asbestos is British Columbia, Canada. A small amount of low-iron long-fiber chrysotile is available from Ariiona. The only source of commercial grades and quantities of amosite is a limited area in Transvaal, Republic of South Africa. The United States is also completely dependent on foreign sources for croddolitc. ENVIRONMENTAL CONSIDERATIONS Many investigators from various countries have established the fact that an occupational or nonoccupational inhalation of dust of different chemical and physical types of asbestos results in the development of asbettosis of the lungs tvhich. depending upon the type of exposure, may be designated as an occupational, neighbor hood. or household pneumoconiosis. The Tizzarris are recognized and steps have been taken by industry to niter the air and properly ventilate mines and processing plants. One leading producer of asbestos instituted programs to prevent possible health and safely hazards and to improve the quality of air and water used in manufacturing operations. Envi ronmental control activities included the devel opment of a rotary Alter system that permits the continual reuse of industrial process water. The new system which asses diatomiie filter aid prod ucts reduces water^demand and eliminates nighsolid-effluent problems (9). An epidemiological survey is being carried on throughout tbe Quebec asbestos industry by the Quebec Asbestos Mining Association as a part of a planned international effort. Fact-finding med ical research on the effect of asbestos on human health was centered in the Thetford Mines and Asbestos districts. Similar surveys are being con ducted in the United States. Finland, the U.S.S.R., Republic of South Africa. Italy, and other countries. Because of the universal use of asbestos and asbestos products, national and in ternational authorities are pressing for careful investigations so that dangers can be identified and controlled (10). Dust control is very impor tant in the asbestos industry and much har done to develop effective control methods and to safeguard the workers in mining and milling op erations. Through ventilation engineering steps have been taken by the asbestos industry to create better working conditions and as a safe guard against industrial diseases (11). No land use conflict problems seem likely to inhibit the production of asbestos. Virtually all of the deposits are in rugged country far re moved from major populated areas. The mining operations are on privately owned or leased lands. Watte rock is hauled to nearby dumps and as the pile builds up, a bulldozer spreads it out. Water sprays allav the dust as the tailings are discharged. The milling of asbestos is gener ally a dry operation and all the screens are hooded and operate under a slight negative pres sure for dust control. The King City, Calif, oper ation of Union Carbide Corp. uses a wet milling ore benefidation method. OUTLOOK DEMAND Domestic demand for asbestos is expected to increase at a moderate rate and to occur within the range from 1,282.000 to 1.865.000 tons in the year 2000. The low of the range indicates an av. erage annual growth rate of 1.4 percent while the high indicates 2.6 pcrcenu The midpoint or median for the forecast range is 1.573,500 toru (fig. 3). The forecast was derived by contin gency forecasting of the major end-use demands considering possible shifts aused by changing technology during the forecast period (uble 1). Much higher than normal growth in demand was experienced by asbestos ia the decade be- FOSECO 1447 F05-00-000O& 860 mineral facts and problems be as high as the growth raie~foF~idiat~nc\v~carr^ --erst--growth--rate (or-gross-- national--product - sirueiion due in part to the great dependence (CNP). on imports to meet demand. Use of asbestos in Asbestos textiles are used in the manufacture floor tile has been increasing in recent years but of yarn and doth which is used in safety cloth because o the many competing materials it is ing. packings, brake linings, filters, etc. Carded not expected to grow at an annual rate ol 4.5 fibers are 100 percent asbestos and are used for percent. Asbestos paper products used in electri the clarification of such liquids as beer. wine. oils, cal appliances as well as in construction are ex and dsemicals. Asbestos lap is a felted form of pected to grow at an accelerating rate but the carded asbestos fiber made (or the electric wire quantity oi asbestos lor such uses is relatively and cable industry, as insulation for heater small. cords, fixture wires, and othcr.electrical conduc A judgment analysis of the demand contin tors. Asbestos rovings are uacdjby the electric gency (acton led to a forecast range lor 2000 of -wire industry as insulationJo^hcaier cords, ca 985.000 tons or l/j of the forecast base for the bles. and electrical heating-elements. The pro low and 1,475,000 or yt of the base (or the high. jected growth of asbestos demand in electrical appliances, coupled with design improvements Transportation that increase asbestos use. could result in in Asbestos is an important pan of many types of friction materials used in automobiles, trucks, and other transportation equipmenL Modem in dustry could scarcely function without asbestos friction materials. In addition to using asbestos in brake linings, today's motor can equipped with automatic transmissions get their drive from metal transmission disks, which are cov ered with a super-tough paper containing crocid- olite asbestos. The average automobile >vith power shift contains eight to 12 of these disks. Although the quantity ef asbestos in each trans mission is small, the output of more than 6 million automatic transmissions annually re quires disk paper production in hundreds of tons. A new composition brake shoe unit contain ing asbestos, designed to meet the cri deal brak ing requirements for the new 150-mile-per-hour passenger train systems, has been developed. In 1968 almost 11 million linear feet of woven brake linings were manufactured containing as bestos yarn. tape, or doth. Based on an esti mated forecast of the number of motor vehicles produced in the year 2000. approximately four times 1968 production, and on the assumpbon that the use of asbestos per vehide will decline to 60 percent of the 1968 levels, the forecast base for asbestos demand in user-operated vehicles is projected to 60,000 tons. Increasing the number creased asbestos demand. On the other hand. , other insulauon materials could replace asbestos for some purposes. Because of its inherent in combustibility and thermal stability, - asbestos doth is extensively used wherever these proper ties are essential in a fabric. Many Government., specifications, particularly those of the Ui. Navy,.require pipe insulation to be protected by .. an outside jacket of asbestos cloth. All maritime specifications and many industrial and utility pow-erplants also require asbestos cloth to bola the insulation in place and to serve as a perma nent protection and fireproof jacket over pipe and boiler insulation. Specially processed lim-iree asbestos cloths also serve as protective shields in "dean" areas adjacent to nudear reactors (7). Competition from substitute material is not likely to be important, and no competitive fac tor is considered. Therefore, the forecast base of 56,000 tons is taken as the low forecasL Produc tion of asbestos textile yarn. cord, and thread in 1965 was 19.7 million pounds, compared with 8.2 million pounds in 1958, and output of asbes tos doth in 1965 was 9.4 million pounds, com pared with 7.5 million pounds in 1958. Data for 1964--68 are not available. Assuming that there will be increased use of asbestos for such items as electrical appliances and firefighting equip ment. the high projected demand could be per haps 60.000 ions in the year 2000. of iransportauon vehides and equipment using pans made of asbestos or maintaining the -pres Plastics ent quantity used per vehide could result in a demand as high as 100,000 tons. It is quite possi ble that the forecast production of vehides will not be attained in 2000. However, the lowest quantity of demand is not expected to be less tnan one-half of die forecast high, or 50.000 tons. The forecast base for 2000 was determined by use of the forecast growth rate for GN'P. Plastic materials can be reinlorccd with such different fibers at asbestos, glass fiber, and coiton. Short asbestos fibers are used in the manu facture of such items as handles on cooking uten sils. and long asbestos is used in the manufacture Textiles of reinforced plastic rocket nose cones. Asbestos phenolic materials are used in acospace applica Demand for asbestos in textiles was projected tions. In many applications glass is a competi to 56,000 tons in the year 2000 based on the fore- tive reiniordng material for plastia. Although \ J FOSECO 1448 fos--003854 asbestos 861 glass fibers have many superior property and processing characteristics, asbestos can often provirir a better combination of heat and corrosion resistance and high strength and" stifIness~"aY lower cost. Asbestos and glass fibers art not al ways competitive materials, and as numerous ap plications demonstrate, they can complement each other. For example, some epoxy pipe wound with high-strengtn giais fiber contains an asbestos-phenolic liner to provide broad chemi cal resistance. Asbestos also can be used in com bination with other reinforcing materials, such as sisal, to produce economic moldings with im proved impact strength and reduced water ab sorption. Auto heater ducting, fan shrouds, and instrument panel components are typical of the many products produced from phenolic rein forced with asbestos and sisal fibers (6). Use of asbestos as a reinforcing material is be coming more significant. However, the base projection of 28.000 tons it not expected to increase importantly unless more use of asbestos is made in the bodies of automobiles as a reinforc ing agent in the joining of various parts and in phenolic materials for aerospace applications. A modest increase of 2,000 tons per year was added to the forecast base for this-contingency. No fac tors are foreseen which appear likely to reduce the demand in the year 2000 below the forecast base. Other Uses On the basis ot past performance it is likely that new uses for asbestos will be forthcoming, and the forecast base of 165,000 tons in the year 2000 was obtained by direct correlation with the projected growth for .GNP. With low-cost short fiber available from domestic sources in large quantities there should be a significant impact on the mineral filler market for a wide range of end products, particularly in products that must withstand high temperatures or corrosive condi tions. The high siae of the forecast range was obtained by adding an increment of 35.000 tons to the forecast base to provide for possible signif icant ina'cases in filler demand. No develop ments are anticipated that would cause demand to decrease below the forecast base. SUPPLY-AND FUTURE SUPPLY-DEMAND RELATlONSHfPS Domestic resources of chrysolite are found mostly in California, Vermont, and Arizona. Al though deposits also exist in Montana. Ore gon, Wyoming, and a few other States, produc tion from these has been negligible. California has the greatest potential of becoming a substan tial producer of short-fiber asbestos. In addition, anthophyllite asbestos is produced in North Car olina. The United States has been dependent on for eign supplies of asbestos for certain essential and strategic grades in the necessary quantities for "times of^emergeTTcyr-Cartada--supplies most--oi-- U.5. requirements for chrysotile.' while amosite and crocidolite originate in the Republic, of South Africa. World expansion and ino-easing demands indicate a possible inadequacy of for eign supplies, thus encouraging the development and production of domestic resources. Such de velopment of domestic asbestos deposit*.coupled with advancing technology in the use of suosti- . tutes. in the manufacture of synthetic asbestos, and in Use removal of iron^trom chrysotile, could reduce our reliancerf^oreign supplies. UJS. and Canadian resources are more than ample to meet-thedugh of the forecast domestic demand for '2000, Without affecting Canadian capability lor supplying a major part of the demand in the rest ot the world. The rela tively small requirements for amosite asbestos will continue to come from the Republic of South Africa unless deposits of this variety of as bestos are discovered in other countries, or ade quate substitutes become available at competi tive prices, thereby providing acceptable options . to the consumers. Crocidolite asbestos will also be obtained from the Republic of South Africa, and perhaps from Australia so long as it remains- competitive with chrysotile but substitution is practicable in essentially all end uses and con tinuation of croddolite supply is not considered cf strategic importance. Estimated demand for asbestos in the United Scates for domestic consumption in 1968 was 817,000 tons, of which about 15 percent came from domestic sources; most of the balance was obtained from Canada' and the Republic of South Africa (fig. 1). Annual requirements (or asbestos in the year 2000 are not expected to ex ceed 1.9 million tom (fig. 4). If the 1968 ratio of domestic production to demand prevails in -------- A 00 300 100 SkiI fiber i 1 1 1 1U c C. 0 -_--_---_--_- ___ 1_--_______L. 0 ft JO -- '' IS. 1 20 * 2ft MILLION SNORT TONS 1 30 Ftcuu Projcnc* Xtoamic Availability ( Aibcuot, FOSECO 1449 FOS--00--0000003S55 -862 SUKLKAL FACTS AND PROBLEMS the year 2000, the domestic production compo nent required to meet the maximum expected terials needed for production of synthetic asbestos are abundant. demand would be 275.300 tons. This production Among the (actors that should tend to in could be accomplished from known resources crease asbestos demand within the next decade is only by much more extensive use of the low-cost, the potential for larger scale production of rela very-short-fiber Coalinga, Calif, material titan tively iow-priced asbestos from domestic depos prevails at present (fig. 4). Historical and pro- its. which should spur research into new uses iected domestic production and demand for as- testos are shown in figure 3. The trend projec and into new ways to substitute very short fiber asbestos for the longer, more expensive types. tions for demand are low compared with Use The domestic product is being used in asbestos forecast range, mainly due to die time periods cement pipe and should be adaptable to other chosen for the trend projections. Based on the '-products. entire postwar period, the demand growth for Work is underway which is-aimed at develop asbestos has averaged about 3J percent per year ing large-scale asbestos uses.--foremost among which is greater than' the rate required to these is the potential for use in asphalt paving achieve the high point of the demand forecast in materials which must bear up under various dif the year 2000. ficult conditions. Examples are airport runways The following tabulation summariaes the and hanpr areas whien are subjected to high- comparative quantities and assigned values (or temperature corrosive effects of jet exhausts: domestic demand and production for 1968 and street curbing, which must be able to absorb 2000. Production figures for 2000 are the con shock and forces from the wheels of motor-vehi stant ratio quantities of figure 3. The values for cles: and resurfacing of old roads. The latter use both demand and production are in terms of requires about 35 tons of asbestos per mile of constant 1968 dollars based on the estimated av 40-foot pavement and probably hat the largest erage domestic sales value of $100 per ton. ~ potential (or large volume asbestos require ments. Technological changes in roadbuilding Q*UtT VlhM (wObM OaiUrO methods could result in capping of new high~ ways with asbestos-rich asphalt. D*ad tm .. 117 .. 171 2000 Kith L** 14sUn IAin 2000 "** Hurt l-- n- ti7 10.4 21 i?i 11 Medical problems connected with asbestos have been under intense study in recent years and undoubtedly will continue to warrant in creasing attention in the future. In addition to study and medical treatment of the effects of as POSSIBLE AD VANCES IN TECHNOLOGY bestos on the respiratory system, work should be aimed at improved methods protecting workers Although asbestos synthesis was accomplished in mines, mills, and fabricating plants.-Among in the late 1920's, and much work has been done the possibilities for solving the problems, in ad since that time, commercial synthesis has not yet dition to medical study and treatment, axe much been announced. However, with the accelerating greater use of automation where feasible, remote rate of technological progress, competitive syn control of fabrication processes, improved pro thetic asbestos or asbestiform products may be tective equipment and respiratory devices, and come available in significant quantities before development and strict enforcement of safety the end of the century. The mineral raw ma procedures. PROBLEMS One of the most serious problems confronting the domestic consuming industry is our depend ence for the greater pan of our supply of asbes tos on foreign sources. About 85 percent of the supply of chrysolite and all of the amosite and o-oddolite comes from foreign countries. Com plete dependence upon foreign supply (or strate gic grades is minimized by adequate stockpiles but imposes long-term concern. . Adequate information on the methods of min ing ana processing of asbestos and development of equipment is available, but cost data are lack ing. Information is available on the principal end products in which asbestos is utilized, but there is no information on the wastage that takes place in manuiacturing the end items. To fully appraise the current future supply situation of asbestos, information is needed on stocks and consumption. Presently, data on con sumption and stocks are available on stockpile grades only. Information on the quantities of as bestos going into the various individual end uses is not satisfactory and the estimates are made on the basis of insufficient data. This illus trates the need-for an occasional canvass of the principal industries in order to establish the quantitative end use consumption pattern. FOSECO 1450 FDS-<&0-00000fc2S5e> ASBESTOS 863 Health haiardt are preterit in the whole ef)nrnrrrfr~rn~r?it"E--pwwnia^, and til<>inj>^as- betiot, and the expanding ute of this material demands continued attention to this problem. REFERENCES ~ `' " 1. Asbestos Textile Institute. Handbook of Asbestos Tex* sites. Philadelphia. Pa, 1961, pp. 29-41. 2. Badollet. M. S. Asbestos. A Mineral ot CnpsrsUcled Properties. Trans. Canadian Inst. Min. aod Meu, r. 54. 1951. pp. 151-160. 5. Bowles. Oliver. Tlse Asbestos Industry. BuMincs Bull. 552. 1955. 122 pp. 4. Burmeistcr, K. tl. and I. E. Matthews. Mining and Milting Mclhods and Costs. Vermont Aabcwos Minn, The Rubcroid Co. Hyde Fast, Vl BuMisica Inf. Circ. 6065. 1962. 43 pp. 5. Cady. W. M. A. L Aibec. and A. H. Childester. Bed* rack Gcolofy and Asbestos Deposits oi tipper kiss* aiaquoi Valley and Viciniry. Vermont. tiiS. Gcel. Survey Bull. 1122-B. 1965. Tl pp. 6. Chidesscr. A. H. and A. F. Shridc. Asbestos in the Untied States (Exclusive of Alaska and Hawaii). VS. Cool. Surrey Miner, lav. Res. Map MR-17. 1962. 7. Cryor, Robert E. Asbestos Reinforced Flsstia Spilt Heat and Cheraiala. Materials in Design-Ejfgl r, 65. No. 4. April 1966. pp. 9&96v 6. Huggins. Charles W.Jdr'VT'btony. aod K. R. Shell. * Froperties o( Falygonkite. an Aibestilorm Mineral. BuMtnes Rcpt. ol Inv. 6071. 1962. 17 pp. 9. Johns-Msnville Carp. Annual Report. 1966. p. 5. 10. Mining in Canada (Ontario). Epidemiological Survey. January 1967, p. 7. 11. --. Health Controls Are Advanced in the Asbestos Industry. October 1967. pp. 55-56. 12. Mining Journal (London). New Asbestos Fiber Lsboraserv---Unique Research Facilities. V. 260. No. 6656. Marl 15. 1965. pp. 249. 2S5. 255. IS. Rice. S. J. CalUomia Ashenos Industry. Calilomia Div. Mines and GeeL Mince, lsl Service, v. 16. No. 9. 1965. pp. 4. 6. _ 14. Rente. D. V. Asbestos, lu Industrial Applications. RcinhoM Fubliabing Carya^ Hear York, 1959. pp. 196-199. 15. Sindair. W. E. Asbestos: Its Origin. Frnriuetion. and Utilization. Mining Publications. Lid. (London). 1955.365 pp. 16. South African Department o( Mines. Geological Sur vey. kiineral Rnourea ol The Union ol South Africa. 4th d. 1959. p. 565. 17. Strithkov. V. V. The Mineral Induury of the U55.2. BuMina Minerals Yearbook 1967, v. 4. 1968, p. 794. I I t it i t - J- FOSECO 1451 frQ5--(3O`-OOO0OO3857