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Section - 2.05.3 <br />Coal Screening Facilities - The coal stockpile reclaim conveyor discharges to a coal screening <br />installation constructed adjacent to the existing dump station. The screening installation's main <br />function is to segregate product-sized (-2-inch) material which can then bypass the crusher in order to <br />maximize overall system capacities. The screening installation consists of two double-deck screens <br />that initially (upper screen deck) screens off the oversize material (+8-inch) which is diverted to the <br />rotary breaker. The reject from the rotary breaker is conveyed to the 125-ton rock bin in the dump <br />station. Undersized material passes through the second screen (lower screen deck) to a crusher <br />bypass conveyor and the intermediate material (-8-inch to +2-inch) discharges to the existing 400-ton <br />coal bin and is fed to the crusher installation via the existing crusher feed conveyor. The reject rock <br />material is recovered from the rock bin by front-end loader for disposal in the active coal refuse and <br />development waste disposal area. <br />Based on typical run-of--mine coal size consistency, approximately two thirds of the coal will pass <br />through both screen decks, leaving slightly less than one third to be transferred to the crusher fox <br />further size reduction. The coal screening installation is fully enclosed within apre-fabricated steel <br />building for dust control. <br />The existing crusher feed conveyor runs from the coal bin in the existing dump station to the crusher <br />installation located in the tipple facility. This conveyor carries the intermediate coal product from the <br />coal bin to the crusher for size reduction to the -2-inch final product size. The crusher bypass <br />conveyor, constructed from the screening installation to the tipple carries the screen undersize which <br />does not require crashing. The crusher bypass conveyor discharges at the same point as the crusher <br />dischazge to the silo feed conveyor. Both the crusher feed and bypass conveyors include partial <br />covers for dust control, walkways, and emergency stop controls for inspection and maintenance in <br />compliance with applicable MSHA safety regulations. Coal transfer points are also partially or fully <br />enclosed for dust control. <br />A portable coal screening plant will be located in the vicinity of the run of mine coal stockpile. The <br />loader fed hopper will feed ran-of--mine coal to a vibrating double deck screen which will then convey <br />the sized coal to 3 different stockpiles. Sized coal product will be loaded into highway trucks for <br />transport to offsite customers. Reject fines will xe-enter the run-of-mine coal process stream. <br />Dump Station -The dump station receives run-of-mine coal and coal refuse ox mine development <br />waste, as an intermediate facility, for temporary storage and transfer to other locations. The dump <br />station is a concrete structure with a rock bin, coal bin, structural steel cover, concrete track ramp, and <br />belt conveyor from the coal bin. The rock and coal bins axe below grade and partially enclosed. The <br />structural steel cover acts as a partial enclosure to minirnlze wind exposure and dust dispersion from <br />truck unloading. In early 1990, a truck scale was added on the east side of this facility. The truck scale <br />is a Cardinal, 10-foot by 60-foot, platform scale with a 60 ton capacity. During 1991 the dump station <br />was modified to allow trucks co drive through the structure in a east to west direction. This provides <br />for an efficient haul cycle because the trucks can run on the scale to be weighed then proceed directly <br />through the dump station where the coal is unloaded. <br />Tipple and Crusher -The tipple is a steel structure on a concrete foundation which receives the <br />screened coal from the screening facility and dump station via conveyor belts Eor crashing and <br />transfer to the coal silo. A double roll crusher housed in the tipple reduces the intermediate coal <br />product Exom the screening facility to -2-inch product size. The crasher was modified during the <br />1997-1998 coal handling system modification to increase its throughput capacity to approximately <br />1,500 tons per hour. The tipple was also modified to accommodate the bypass conveyor from the <br />new screening installation and an increase in the size of the silo feed conveyor. The silo transfer <br />conveyor transfers coal from the crusher discharge and crusher bypass conveyor to the silo headhouse <br />at the top of the coal storage silo. Associated with the tipple is a fenced transformer station and a <br />wood frame control building. <br />TR-45 2.05-43 Rev. February 2004 <br />