|(Table 1) The production of chrysotile asbestos within Russia and the USSR, thousand tonnes of fiber|
|Years||The output of the products|
|0-VI grades||0-VII grades|
ASBESTOS INDUSTRY (EN: asbestos industry; DE: Asbestindustrie; FR: Industrie d'asbeste, industrie d'amiante; ES: industrie del asbesto; RU: асбестовая промышленность) is the sub-branch of the industry of the building materials within the USSR, which is engaged in the extraction and beneficiation of the asbestos ores, and in the production of the marketable asbestos. The origin of the asbestos industry belongs to the end of the 19th - start of the 20th century, when, in association with the rapid development of technology, there have expanded the industrial usage of asbestos, and the production of the asbestos-cement products. The major centres of the developing asbestos industry at that time were Italy and Canada.
Within the pre-revolutionary Russia, the development of the asbestos ores was conducted at the small open pit mines, where prevailed the manual labour and animal-powered transport. After the October Revolution of the 1917, there are introduced at the open pit mines for the extraction of asbestos the pneumatic equipment for the drilling of the holes (Bazhenovskoe deposit), steam locomotive railway transport, cable cranes, inclined lifts, steam excavators, and so on. Since the 30-ies, there is being improved the mining transport equipment (the drilling rigs for the cable-churn drilling, and others), are developed the schemes for the opening of deposits by the inclined ramps at the edges of the open pit mines. In the 1935, there has been used at the Bazhenovskoe deposit the method of the dry gravity beneficiation of the ores, which is based on the difference of the aerodynamic properties of the asbestos fiber, which has been unsealed and fluffed during the crushing.
This technology included the suction of the fiber from the flat-swinging sieve screens after the multiple crushing, and also its subsequent dedusting and classification according to the length. The creation and improvement of the technology of the open pit mining works and beneficiation of the asbestos ores are the most characteristic features of the pre-war stage of development of the asbestos industry. During the Great Patriotic War of the 1941-45, for the first time within the world, there has started to be used at the asbestos open pit mines the excavator method for the forming of the waste rock disposal dumps (1943). During the 2nd half of the 40-ies - 60-ies, there have been built new combined enterprises, there has been planned the development of the deposits by the deep open pit mines (down to the depth of 680 metres). The height of the working benches at the open pit mines has increased up to 15 metres. The railway transport has been transitioned to the electrical traction and the track gauge of 1524 millimetres. There has been started the usage of the automobile transport, excavators with the bucket with the capacity of 4.6 and 8 cubic metres, drilling rigs for the rotary drilling of the blasting boreholes, was performed the comprehensive mechanization of the blasting works. In the 1965, there has been founded the largest within the world "Uralasbest" combined enterprise (on the base of the Bazhenovskoe deposit). During the 60-ies, there have started their activity the "Tuvaasbest" (on the base of the Aktovrakskoe deposit) and "Kustanaiasbest" (on the base of the Dzhetygarinskoe deposit) combined enterprises, in the 1979, the "Orenburgasbest" (Kiembaiskoe deposit) combined enterprise. The open pit mines of these mining-extracting enterprises, with productive capacity from 15 to 180 million tonnes of the rock mass per year, and with the depth of 60-250 metres, are provided with the highly productive mining-transport equipment.
The asbestos-beneficiation plants are the highly mechanized and automated enterprises, which are equipped with effective beneficiation machinery, and with installations for the dust suppression and cleaning of the air of the dust up to the sanitary norms. The average capacity of beneficiation plants for the production of asbestos is 330 thousand tonnes. Within the USSR, the reserves of asbestos have been explored at 28 deposits, mostly at the Middle and Southern Urals, and at the south-east of Siberia.
|(Table 2) The production of asbestos, thousand tonnes of fiber|
|Cyprus||5.5 (2)||9.7 (2)||15||21.2||25.7||30.4|
|(1) Without the socialistic countries, (2) The data are on the export, (3) The estimated data|
The reserves of asbestos are taken into account by the governmental balance for the industrial fiber with the length of more than 0.5 millimetres (see the "Asbestos" article). The shorter fiber, which is contained within the asbestos ores, is partially involved during their beneficiation into the products, and participates in the forming of marketable grades and marks of asbestos. As the consequence of this, the volume of the marketable asbestos exceeds by 1.6-1.7 times (depending on the technological schemes of the beneficiation plants, and on the range of products of the asbestos, which is being obtained) the quantity of fiber, which is taken into account within the ores, which have been extracted and processed. The fatherland asbestos industry produces the asbestos of the 44 marks, which are unified into the 8 grades (0-VII), depending on the fractional composition, content of the dust-like particles, and other technological characteristics (they are regulated by the GOST 12871-67 standard). Within the USSR, there is mostly extracted the chrysotile asbestos. In the production of asbestos, the USSR holds the 1st place within the world since the 1958 (Table 1); the products are exported into the 49 countries of the world.
The raw material base ensures the work of the asbestos combined enterprises for the long period of time, and significant expansion of their productive capacities. The level of mechanization within the major production is 100%, the auxiliary and repair works are mechanized for 72.4%. There are introduced the automated systems for the control of the regimes of the technology of beneficiation, of the quality of the ore, which has been extracted, and is supplied into the plants (the "Kustanaiasbest" combined enterprise), and also of the entire production (the "Uralasbest" combined enterprise). The asbestos, which is produced, is the raw material for the products of more than 3 thousand names. The major field of its usage is the production of the asbestos-cement pipes and slates. The asbestos-cement industry of the USSR uses approximately 65% of the asbestos, which is produced. The large consumer of the asbestos (mainly of the long-fiber one) is the asbestos-technical industry, which is producing the products of the textile (woven fabrics, cords, ribbons), and also of the plastics and rubber with asbestos as the filler (brake pads, friction rings, electrical insulating materials, and others). Asbestos is also used for the production of the special paper and cardboard, of the filters.
The worldwide production of asbestos (without the USSR) is 2.4 million tonnes (1978). The largest producers of asbestos among the industrially developed capitalistic and developing countries are Canada (62.2%), South Africa, Zimbabwe, Italy, Australia, and the USA (Table 2).
Significant quantity of asbestos is extracted within China (203.8 thousand tonnes of fiber in the 1979). Their own consumption of asbestos by the largest producing countries is, as a rule, insignificant; the bulk of the raw materials is exported. The main importers of the products are the USA, Japan, West Germany, France, Great Britain. The technique and technology of the extraction and beneficiation of asbestos ores abroad and within the USSR are practically identical. The extraction is performed mostly by the open pit method, but within the South Africa, Zimbabwe, and Canada, in small volumes, by the underground one. The major companies for the extraction of the asbestos ores and production of asbestos are: the "Calaveras Asbestos Corp.", "Atlas Asbestos Corp.", "Union Carbide Corp." (USA), the "Johns Menvilie Canada Inc.", "Cassiar Asbestos Corp.", "L'Association des Mines d'Amiante du Quebec", "AMAQ" (Canada), the "Cape Industries, Ltd." (South Africa), the "Woodsreef Mines Ltd." (Australia). The largest asbestos-extracting companies are the "Jeffrey", "Carey Canadian" (2 open pit mines with productive capacity of 2.5 million tonnes of ore per year, and beneficiation plant with the capacity of 230 thousand tonnes of asbestos per year).
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