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Results 41 - 45 of 45
1/1/1992 - Information CircularsA U.S. Bureau of Mines investigation of longwall panel layouts to maximize coal recovery and minimize interactive problems in multiple-seam operations.
1/1/1992 - Reports of InvestigationsThis U.S. Bureau of Mines report summarizes a study of large-scale strata response to longwall mining at a western U.S. coal mine. This study utilized surface and subsurface measurements, geologic mapping, in situ stress measurements, and pressure cell...
1/1/1986 - Reports of InvestigationsThe Bureau of Mines conducted studies to compare the effectiveness of the cross-measure borehole system with that of surface gob holes on two successively mined retreating longwalls in the Lower Kittanning coalbed. Only the cross-measure system was in o...
1/1/1977 - Reports of InvestigationsThe Bureau of Mines evaluated the hydraulic stimulation of a gob degasification borehole to determine if this procedure would aid in degasifying a longwall panel.
3/1/1969 - Technical Progress ReportsAn experimental degasification program using a vertical borehole and vacuum pump to drain gas from the gob area of a longwall panel was successful at Bethlehem Mines Corporation, Cambria Division, No. 33 coal mine. Sixty-one million cubic feet of methan...