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Two additional seams are known to exist in Coal Basin. They are the "A" <br /> seam, which lies below the B Bed, and the "Placita" seam, which overlies <br /> the Middle bed with a stratigraphic separation of around 250 feet. Mining <br /> of these seams, is presently considered uneconomical mainly because of <br /> irregular bedding and variations in seam thickness. <br /> In 1974, Mid-Continent installed the first advancing longwall mining <br /> system in the United States. The advancing longwall is a mining technique <br /> which has been used in Europe and Asia for recovery of coal reserves at <br /> depths of 2,500 to 3,500 feet. It is the best method currently available <br /> for recovery of coal at depths below 2,000 feet. <br /> Recently the Department of Energy contracted with Mid-Continent to carry <br /> out an experimental program in the multi-lift longwall mining technology. <br /> The program is intended to develop mining techniques to increase coal <br /> recovery in deep mines. <br /> Mid-Continent has also introduced the use of volley firing and remote <br /> control for mine machinery to assure greater safety when mining coal which <br /> has a proneness to outburst. <br /> The run-of-mine coal is transported from the mine portal bins to the <br /> preparation plant in off-highway diesel powered trucks. Each of the mines <br /> is located approximately 4 miles from the preparation plant. At the <br /> preparation plant, rock and refuse materials are removed from the coal by <br /> gravity separation methods and froth flotation. After cleaning, the coal <br /> is thermally dried and placed in clean coal storage bins. The coal is then <br /> loaded into semi-trucks and transported 22 miles to the unit train loadout <br /> facility near Carbondale. Rock and refuse materials removed from the coal <br /> at the preparation plant are placed in refuse piles situated in Coal Basin <br /> near the preparation plant and below Mine No. 4. <br /> The projected life of the mine is 40 years. Reclamation will proceed <br /> following the completion of mining operations. The disturbed areas will <br /> be graded, topsoiled where sufficient material is available, and seeded <br /> with predominantly native species. Vegetation characteristics will be <br /> monitored until the post-mining conditions are approximately equal to <br /> adjacent areas of comparable vegetation. The final reclaimed surface will <br /> blend in with the surrounding undisturbed areas. <br /> The Mid-Continent operations are economically feasible only because the <br /> coal is of premium coking quality. It is one of the few known deposits of <br /> medium-volatile coking coal (essential to steel production) west of the <br /> Mississippi River. <br /> The coal produced at Coal Basin is transported to the Geneva works of the <br /> U. S. Steel Corp. in Provo, Utah, and to the Fontana works of Kaiser Steel <br /> Corp. in Fontana, Calif. Steel is produced in the western United States <br /> from only a few operations, of which the Geneva and Fontana works are the <br /> largest. <br /> -3- <br />