SUMMARY
Asbestos is a unique mineral for the reason that it combines incombustibility and insulating qualities with a fibrous structure that makes possible its manufacture into fabrics, felts, and similar wares. The spinning grades of asbestos are most in demand and the problem of supply hinges largely on the deposits of high-grade chrysotile. Such material is used for the manufacture of ropes, safety curtains, mats, packings and friction facings in brakes. The lower grades are used for making fireproof shingles and other building materials, for insulating, and for fire brick, acid filters, etc. Although some substitutes may be found for the lower grades, no substitutes are known for spinning fiber.
Asbestos occurs in three main types, chrysotile, crocidolite, and anthophyllite; the first and second provide most of the spinning fiber, and the third is almost all of non-spinning quality. The most important deposit of chrysotile asbestos is in Quebec, Canada, but large deposits are worked in Russia and Rhodesia. Crocidolite is mined only in Cape Colony, South Africa. Large deposits of anthophyllite occur in the United States, Italy, and Cyprus.
The United States is by far the largest manufacturer of asbestos products in the world, but produces only a small fraction of the necessary raw material; it is practically assured of an ample supply of this because the largest deposits in the world are in the adjacent Province of Quebec, Canada. The Arizona deposits provide an excellent grade of fiber and constitute a promising supplementary source of supply, though the estimated reserves are not great. The British Empire holds a dominating position, controlling about 88 per cent. of the annual asbestos production of the world and approximately 70 per cent. of the estimated reserves. Canada is far in the lead of all countries, supplying about 85 per cent. of the world’s output. Russia was, before the revolution, second to Canada as a producer; because of the cost of transportation the chief output is spinning fiber. South Africa has large reserves of good fiber, but the output is handicapped by poor transportation.
Exhaustion of the chief sources of supply is not likely for many years, nor is there immediate prospect of any material shift in the centers of production, though with improved transportation a shift to South Africa is possible. The demand for high-grade asbestos will probably increase at a steady rate.
All the asbestos quarries in the United States seem to be American owned. The Canadian deposits are controlled by Canadian, English, and American capital, British interests probably being predominant. British companies evidently hold exclusive control of the present output in South Africa, Australasia, and Italy. Before the war the Russian output was largely controlled by a German syndicate, and the Cyprus output by an Austrian company.