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calcareous to slightly ferruginous cement and minor argillaceous and <br />• carbonaceous shale partings. Based on analysis of material removed from the <br />mine the following particle size distribution was obtained. <br />Size Distribution <br />Material above 6" 20% by weight <br />Material above 4" 30% by weight <br />Material above 2" 30% by weight <br />Material above #4 mesh' 10% by weight <br />Material above #10 mesh' S% by weight <br />Material above #40 mesh' < 5% by weight <br />Material above #200 mesh' <5% by weight <br />'U.S. Series equivalent screen size <br />This information was provided by National King Coal <br />The following table summarized material properties for the waste rock. <br />Material Strength <br />Approx. dry density = 86 pcf <br />Maximum dry density = 91 pcf <br />Optimum moisture content = 12.0% <br />lntemal angle of friction = 32° <br />• Cohesion = 2.8 psi <br />Relative toughness = 1.5 <br />Ft-IbJft2 of fracture = 312.4 <br />Compressive strength, 9500 psi (no partings) <br />Compactive 12.5% <br />Compressive strength, 8400 psi (partings) <br />This data was supplied by King Coal <br />Coal Waste Pile Configuration <br />The criteria used in designing the waste pile were 1) to be structurally stable, <br />2) provide 1,000,000 cubic yards of storage volume and 3) to provide adequate <br />surface and subsurface drainage. Please refer to design drawing sheets 1 and 2 <br />for details. <br />The waste pile will begin at the toe of the existing waste bank, across the <br />access road from the coal storage pile and extend up valley about 1600 ft. The <br />waste pile will have a front face slope of 2.5:1, extend across the valley from side <br />to side and have a maximum thickness of 200 ft at the top of the front face. It will <br />slope upvalley at 1% and will have a cross slope of 2% with the high side on the <br />north. <br /> <br />January 1998 <br />