2024-09-05_PERMIT FILE - C1980007 (2)

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