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West Elk Mine <br />developed using continuous miners in a series of main entries, submain entries, and gate entry <br />development. In 1990, slopes were driven from the existing F Seam main entries in Section 21, <br />T13S, R90W to the underlying B Seam. A similar system of main entries, submain entries, and <br />gate entry development continues in the B Seam. Development of main and submain entries and <br />longwall panels in the E Seam was initiated in June 2004 from the existing F to B Seam slopes. <br />MCC utilizes two methods of mining coal at West Elk Mine. They are room and pillar for <br />development mining and a retreat longwall system for production mining. Room and pillar <br />mining has been the only method used in the F Seam. It is currently used in the B Seam for <br />development mining and is planned for development of the E Seam. Longwall mining is <br />occurring in the B Seam and is the planned method of production mining in the E Seam. <br />Room and Pillar Mining Method <br />Development mining at West Elk Mine involves driving entries through the coal seam and <br />leaving coal blocks to support the overlying strata. The resulting entries provide travel -ways, <br />ventilation, and locations for installing infrastructure to support mining activities. This <br />infrastructure includes conveyors, power, water, communications, rock dust, etc. <br />MCC uses a system of continuous miners, haulage vehicles, and a conveyor system to cut and <br />transport the coal out of the mine. First, continuous miners cut the coal from the seam. This cut <br />coal is then loaded from the miners into diesel or electric haulage vehicles. Finally, the haulage <br />vehicles transport the coal to the conveyor system for transportation out of the mine. After a cut <br />of coal is mined, a roof bolter moves in and installs roof bolts to support the roof. Conventional <br />twin -boom roof bolters will provide primary roof support by installing resin -anchored roof bolts, <br />conventional roof bolts, combination roof bolts, or other approved systems. Bolt length and use <br />of plates, mats, and mesh or other supplemental materials are determined by roof conditions. <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 roof support means. For support of long -life entries, air -courses, critical <br />ancilliary installations, overcasts, and other permanent or semi-permanent facilities, <br />supplemental roof support may be installed, if inspections indicate that the roof is weakening. <br />Supplemental roof support is currently utilized in the longwall panel bleeder and tailgate entries. <br />The roof control plan also includes provisions for installing supplemental support if a loose or <br />badly sagging top is detected or where abnormalities are discovered. <br />Main Entries & Sub -Main Entries <br />At West Elk Mine, from five to nine entries currently are 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 on 60 to 100 foot centers. Crosscuts are on 100 to 200 foot centers. The entries are <br />also separated as necessary by stoppings. <br />205-7 Rev 11/04- PRI 1, 03/06- PRIO <br />