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West Elk Mine <br /> <br />2.05-8 Rev. 11/04- PR11; 03/06- PR10; 07/15- MR413; 07/18- PR15, 01/24-TR152, 04/24-TR154 <br />Room and Pillar Mining Method <br /> <br />Development mining at West Elk Mine involves driving entries and cross-cuts through the coal <br />seam and leaving coal blocks to support the overlying strata. The resulting entries provide <br />travel-ways, ventilation, and locations for installing infrastructure to support mining activities. <br />This infrastructure includes conveyors, power, water, communications, rock dust, etc. <br /> <br />For development mining, MCC uses a system of continuous miners, haulage vehicles, and a <br />conveyor system to cut and transport the coal out of the mine. First, continuous miners cut the <br />coal from the seam. This cut coal is then loaded from the miners into diesel or electric haulage <br />vehicles. Finally, the haulage vehicles transport the coal to the conveyor system for <br />transportation out of the mine. After a cut of coal is mined, a roof bolter moves in and installs <br />roof bolts to support the roof. Conventional twin-boom roof bolters provide primary roof <br />support by installing resin-anchored roof bolts, conventional roof bolts, combination roof bolts, <br />or other approved systems. Bolt lengths and use of plates, mats, and mesh or other supplemental <br />materials are determined by roof conditions. <br /> <br />The mine has a MSHA-approved roof control plan to provide protection under the anticipated <br />conditions. Roof support materials that are allowed under this approved plan include mechanical <br />roof bolts, roof trusses, resin-anchored roof bolts, timbers, resin-anchored cable bolts, steel <br />crossbars, yieldable arches, crossbars, wire mesh, concrete props called “cans” and other <br />commonly used mine roof support means. For support of long-life entries, air-courses, critical <br />ancillary installations, overcasts, and other permanent or semi-permanent facilities, supplemental <br />roof support may be installed, if inspections indicate that the roof is weakening. Supplemental <br />roof support has also been utilized in the longwall panel bleeder and tailgate entries. The roof <br />control plan also includes provisions for installing supplemental support if a loose or badly <br />sagging top is detected or where abnormalities are discovered. <br /> <br />Main Entries & Sub-Main Entries <br /> <br />At West Elk Mine, from five to ten entries are typically mined as main entries. The number of <br />entries depends on mining conditions, and ventilation and access requirements. As few as three <br />entries could be driven in special circumstances. The entries are used for intake and return air <br />ventilation, coal haulage, and men and material transportation. The entries are driven parallel to <br />each other and are generally on 100 to 200 foot centers. Crosscuts are also generally on 100 to <br />200 foot centers. The entries are separated as necessary by stoppings. <br /> <br /> <br />Room and Pillar Panels <br /> <br />F Seam room and pillar panels generally consisted of 6 to 8 entries driven on 60 to 100 foot <br />centers and with crosscuts on 60 to 120 foot centers. During secondary mining of the room and <br />pillar panels, additional rooms may have been developed on one or both sides of the initial <br />development. Sufficient barrier pillars were left to protect the main entries and bleeder entries (if <br />separate bleeders were utilized). During secondary mining, partial or full pillar extraction was <br />completed, depending on conditions in the panel.