Oil-shale Mining

Abstract The term oil shale is defined. Foreign oil shale developments are outlinedbriefly. The richest and most extensive oil-shale deposits in the United Stateslie in western Colorado. The Bureau of Mines is opening two adjacent areas forunderground mining in western Colorado. From the first area the oil shale ismined selectively as required by the retorting plant. The second area is beingdeveloped as a unit of a full scale oil-shale mine to ascertain the mostpractical methods of mining oil shale and to determine costs. In both of thesemining areas, research will be carried on to develop new and improved practicesfor mining oil shale. Introduction Oil shale is a sedimentary rock containing a solid mineraloid of indefinitecomposition known as kerogen. On heating oil shale, the kerogen undergoesthermal decomposition and some of the vapor products of the decomposition canbe condensed as shale oil. Oil from shale can be a major source of liquid fuelssince extensive deposits of oil shale are known to exist throughout the world.The United States considers the establishment of an oil-shale industry onlywhen doubt exists of the adequacy of the domestic supply of crudepetroleum. On the other hand, oil shale is not strange to foreign oil men. The industryis an old one in other parts of the world. The French industry has been inexistence since 1838, the Scottish since 1859, the Australian since 1860, theEstonian and Swedish industries since World War I, and the Manchurian industrysince 1929. The most highly exploited oil-shale deposits are the Carboniferous shales ofScotland. About 20 seams ranging from 4 to 12 ft in thickness are worked. Theyield during recent years in Scotland has been 18 to 25 gal of shale oil perton, from 3,000,000 tons per year. The French and Swedish oil-shale depositsare of lower grade than the Scottish. The Estonian oil shale deposits are 7 ftthick, and the oil yield averages 50 gal per ton. Over 1,000,000 tons are minedeach year, half of which is used directly as fuel to substitute for coal andthe other half is used for the production of oil. T.P. 2359