the branch of the fuel industry concerned with the mining and processing of oil shales.
The shale industry underwent considerable development in the 19th century in Great Britain. In prerevolutionary Russia, the industrial exploitation of oil shales began in Estonia during World War I in order to supply the Petrograd industrial region with fuel. The shale industry has undergone great development in the Soviet period. In July 1918 the Council of People’s Commissars of the RSFSR, at the initiative of V. I. Lenin, adopted a decree on the mining and processing of oil shales. Systematic study and exploration of shale deposits were instituted, and the industrial exploitation of the deposits was organized.
In 1975 the USSR led the world in the mining of oil shales. Shale deposits are found in the Baltic shale basin, which includes the Estonian and Leningrad deposits, and in the Volga basin, with its Kashpir and Obshchii Syrt deposits. These basins contain 75.2 percent and 19.7 percent, respectively, of the known reserves of the USSR. The mining of oil shales is concentrated at the Estonian, Leningrad, and Kashpir deposits. (See Table 1 for statistics on shale output for the USSR.)
|Table 1. Shale output in the USSR (thousand tons)|
Ten underground and four open-pit mines were in operation in 1974. In the open-pit mines, a nontransport system of mining is employed involving the use of large excavators. In the underground mines, integrated mechanization of the mining processes is being carried out. At the largest underground mines concentration plants have been constructed that make use of wet and heavy-media separation processes. The level of mechanized concentration of shales was 57.7 percent in 1974, as opposed to only 35 percent in 1970.
The production association Estonslanets provides more than 80 percent of the entire output of oil shale in the USSR. The largest mines are the Estoniia mine of Estonslanets, which produces 5 million tons of marketable shale annually, and the Leningradskaia mine of the production association Leningrad-slanets, which has an annual output of 3.7 million tons. The shale industry is distinguished by a high degree of concentration of production: the average daily output of one underground mine in 1974 was 5,727 tons, and the monthly output per mine worker was 199.8 tons.
Oil shales are used for power and industrial purposes. Shale fuel is used by all the electric power plants in the Estonian SSR and by steam power plants in the city of Slantsy in Leningrad Oblast and in the city of Syzran’ in Kuibyshev Oblast. Oil shales, especially the Estonian varieties, are a cheap source of various valuable chemical products. In the Estonian SSR and in Leningrad and Kuibyshev oblasts, shale processing plants are in operation that produce fuel oil, town gas, gasoline, sulfur, impregnating oil, tanning agents, toxic chemicals, asphalts, carbamide resins, antiseptics, and dyes. Liquid fractions resulting from the distillation of shales are used to produce, for example, benzene, ichthammol, toluene, shale solvent, varnishes, adhe-sives, and electrode coke. About 1 billion cubic meters of town gas are produced annually from shale.
Noncombustible mineral substances account for two-thirds of the composition of oil shales. When oil shale is burned in the furnaces of electric power plants, these substances acquire binding properties and are a cheap source for the production of construction materials. Products made from these substances include building blocks, foam concrete, agloporit. partition slabs, and drain pipes. Shale ash is used in agriculture.
The principal lines of development of the shale are as follows: the introduction of new, more advanced techniques and technological processes for the mining and processing of oil shales; the multipurpose use of oil shales in the economy; and the recovery of all the useful components of oil shales.
Oil shales are also mined in China. There are oil shale deposits in Albania, Bulgaria, Hungary, Cuba, Rumania, Czechoslovakia, Yugoslavia, Austria, Brazil, Great Britain, Egypt, Spain, Canada, Mali, Morocco, the USA, the Federal Republic of Germany, and Sweden.
REFERENCESRazrabotka i ispol’zovanie zapasov goriuchikh slanlsev: Trudy I Simpoziuma OON po razrabotke i ispol’zovaniiu zapasov goriuchikh slanlsev (Tallin, 26 avgusla-4 sentiabria 1968). Tallinn, 1970.
Balans zapasov poleznykh iskopaemykh SSSR na i ianvaria 1974 g., fasc. 59: Slanlsy goriuchie. Moscow, 1974.
A. P. PETROV