large mining and ore-enriching combines at which the mining and production of asbestos are carried out.
Of the various types of asbestos the most important for industrial use is chrysotile asbestos. Asbestos materials and products are utilized more and more extensively for the national economy and for defense, and in the motor vehicle and tractor, aviation, and tank industries, as well as in electric-power engineering, machine building, construction, railroad transport, and other fields. At the beginning of the 20th century the worldwide mining of asbestos amounted to approximately 30,000 tons per year; in 1937 it exceeded 600,000 tons; and in 1966 it amounted to more than 3.5 million tons. More than 3,000 different materials and products are turned out which utilize asbestos (asbestos-engineering, asbestos cement, and asbestos heat-insulating materials and products). Asbestos is classified depending upon fiber length (from 0.25 mm to 18–25 mm) into eight grades—from grade 0 to 7.
In remote antiquity asbestos fiber was used to make non-combustible wicks for lamps and clothing for priests. The art of making asbestos fabric was known in ancient Greece. China, India, and Judea. The mining of asbestos on a large industrial scale was begun in Canada during the 1870’s. In Russia the asbestos industry began to develop during the end of the 19th century, when industry started to make more and more extensive use of medium-length and short-length fiber grades of asbestos for producing various kinds of heat-resistant products as well as asbestos cement building materials. This was facilitated by the discovery in 1885 of the Bazhenov deposit of asbestos in the Urals (Sverdlovsk Province). It was the largest deposit in the world, and its industrial development began in 1889. During the pre-revolutionary period this deposit was exploited in a predatory manner, in the sections where the richest, long-fiber asbestos was located. Both mining and ore dressing were done manually, and the amount of asbestos extracted was extremely low. In 1913 more than half of the asbestos produced in Russia was exported, whereas asbestos products were imported.
The asbestos industry of the USSR was essentially created during the years of Soviet power. The reconstruction of mines and factories begun after the October Revolution was completed in 1928, when the output surpassed the 1913 level and reached 25,400 tons. During the prewar five-year plans (1929–40), considerable work was accomplished in reconstructing the Bazhenov mine, and new, large ore-enriching Factories No. 2 and No. 3 were built. After the war extensive geological surveys were conducted at the Bazhenov deposit as well as at new deposits—Ak-Dovurak (Tuva ASSR), Dzhetygarina (Kustanai Oblast), Kiembaev (Orenburg Oblast), and Il’chir and Molodezhnyi (Buriat ASSR). As a result, the discovered reserves of asbestos increased considerably. At the Bazhenov deposit new layers of ore were revealed, extending to a depth of 1,500 m. This increase in the discovered reserves of asbestos made it possible for the reconstruction of the asbestos mines to go forward. The complex mining and geological conditions of the deposit and the comparatively low asbestos content in ore (an average of 2.64 percent) made it necessary to process up to 55–60 tons of rock mass in order to obtain 1 ton of asbestos of all grades. The ore-enriching Factories No. 2 and No. 3 were also redesigned, and new, high-power Factories No. 4 and No. 5 were built. In 1965, moreover, the first units of the Kustanaiasbest Combine were put into operation; its annual productive capacity is 250,000 tons—mostly slate and the insulating grades of asbestos. In 1964 the Tuvaasbest Combine began work with a capacity of 20,000 tons—basically to satisfy the requirements for the higher (textile) grades of asbestos. The dynamics of growth in asbestos production are shown in Table 1.
|Table 1. Asbestos production in the USSR (all grades)|
|Name of combine||1913||1940||1950||1955||1960||1965||1969|
In 1960 the USSR was in first place in world asbestos production.
The implementation of comprehensive mechanization of mining operations along with the introduction of highly productive equipment and efficient technology has made it possible to greatly increase labor productivity at asbestos mines and ore-enriching factories. In comparison with 1940 the annual amount of rock mass mined per worker in 1965 had increased by 430 percent and the annual production of asbestos by 290 percent.
During the five-year plan of 1966–70 the asbestos industry underwent further growth. At the Bazhenov mine the largest asbestos-processing mill in the world was put into operation—Factory No. 6, with the capacity of processing 12 million tons of poor-quality ore per year. Since this factory began operating, asbestos production at the Uralasbest Combine has reached 2 million tons annually. Now under construction are the Kiembaev Combine and secondary units of the Tuvaasbest and Kustanaiasbest combines.
Among foreign socialist countries asbestos is mined in China (approximately 120,000 to 150,000 tons per year), Yugoslavia (about 10,000 tons), and Bulgaria (about 1,500 tons).
In the capitalist countries the basic reserves of asbestos and its mining are controlled by large monopolies in the USA and Great Britain. The most highly developed asbestos industry is in Canada (primarily in Quebec Province), where the grade composition of the asbestos is close to that found in the Soviet Union. The great majority of this asbestos is exported (more than half to the USA). Asbestos of the textile (long-fiber) grades is mined in rather large quantities in the Republic of South Africa, from which almost all of it is exported.
|Table 2. Asbestos production in several capitalist countries|
|Republic of South Africa||30,000||26,000||79,000||244,000|
REFERENCESSokolov, P. N., and V. E. Shneider. Asbest. Moscow, 1959. (Trebovaniia promyshlennosti k kachestvu mineral’nogo syr’ia, vol. 5.)
Ryskin, M. V. Asbest: Rynok kapitalisticheskikh stran. Moscow, 1960.
Shchedrinskii, M. B., A. V. Volegov, and E. K. Miuller. Obo-gashchenie asbestovykh rud. Moscow, 1962.
[VNII—proektasbest.] Nauchnye trudy. Vol. 6: Otkrytaia razra-botka mestorozhdenii asbesta. Moscow, 1964. (State All-Union Scientific Research and Planning Institute of the Asbestos Industry.)
Promyshlennost’ stroitel’nykh materialov SSSR, 1917–1967. Moscow, 1967.