Laserfiche WebLink
• 2.05.3 page 2 <br />STRUCTURAL CONSIDERATIONS OF THE MINE LAYOUT <br />King Coal workings are confined to the upper Menefee (Pueblo) coal seam of the Menefee <br />formation (Mesa Verde Group). The seam is about six feet in thickness. The equipment used in the <br />mine and the mining method itself is tailored to this seam's structural contours. The seam dips at a 3% <br />grade to the Southwest. The strike of the seam is S 55° E. For specific details of the local geology and <br />information concerning adjacent rider coal seam see Section 2.04.6. <br />For practical purposes the upper Menefee seam may be considered flat or tabular with no <br />rolling of seam. Consequently, the layout of the mine workings are no[ dependent upon the steepness <br />of the seam as it is upon the boundary lines of the coal leases. The panels or mining sections are laid <br />out as shown on Map C-3 to maximize the recovery of the lease coal. Most of the underground <br />openings or entries are driven along some given angle to the true dip to take advantage of the property <br />boundaries. This angle cannot be correlated to the cleat of the coal. The tight cleat allows the mine <br />workings [o be oriented without rib spalling problems arising. In addition, [he lack of ground water <br />seepage allows the workings to be laid out without regard to drainage slopes. <br />The main stnictural consideration of the mine layout is the width of the panels (number of <br />multiple entries) and the width of the entries. A panel width of 250 to 300 feet with five entries has <br />proved satisfactory for development and pillar extraction. This width allows for room development <br />upon retreat from the panel during pillar extraction. Stresses due to overburden thickness aze minimal <br />compared to deeper operating coal mines. Maximum over-burden cover does not exceed 325 feet at <br />any point, and the stress field seems to act in a vertical direction. No ground forces other than vertical <br />have been observed by inspection during mining operations. The shallow overburden cover would <br />accommodate an increase in the panel width or the number of multiple entries without undue stress <br />• problems. No major Vaults or slip planes criss-cross the mine workings allowing for an even greater <br />degree of optional orientation of the workings. The width of the openings have been limited to twenty <br />feet for control of the immediate roof (the thickness of the roof to the top of the resin bolting horizon). <br />ANTICIPATED PRODUCTION <br />While current production is stable at about 200,000 tons per year, i[ is anticipated that <br />production may reach 300,000 tons per year. <br />OPERATION PLAN -PERMIT AREA <br />MINE BENCH <br />The surface disturbed azea includes the mine bench and the access road to the mine bench. <br />Total disturbed acreage is 10.88. All surface facilities for the support and, processing of coal have been <br />constn~cted on the mine bench. No surface mining operations exist on [he mine bench; all coal <br />extraction activities are confined to [he underground King Coal Mine. <br />Map C-4 shows the permit area which includes the mine bench. Facilities constructed on the <br />bench include office building, bath house, shop, scale house, security trailer, office trailer, guard shack, <br />tipple area with numerous coal storage bins, coal stocking (storage) areas, a main fan, 10,000 gallon <br />water storage tank, and asub-station. <br />• <br />February 1997 <br />