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• In the rotary breaker, large rocks and foreign material are removed from the ROM coal. The raw <br />coal is then placed on a conveyor and transported to twin 10,000-ton raw-coal silos from which the <br />coal is delivered via conveyor either to the coal preparation plant for cleaning or, quality permitting, <br />directly to the 25,000-ton slot storage. <br />After processing in the preparation plant, the clean coal is transported by conveyor to the <br />25,000-ton slot storage facility to await shipment to the power plant. A sampling system and scale <br />are provided between the preparation plant and the slot storage. <br />III.B.2 Coal Preparation Plant The preparation plant processes the ROM or raw coal through a <br />mechanical gravity separation process. A fine coal froth floatation circuit is available to increase <br />recovery of fine coal and decrease the amount of refuse to be disposed of. After the clean coal is <br />separated from the refuse it is mechanically dewatered by vibrating-screen type centrifuges, <br />classifying cyclones, and cross-flow screens. After the coal surface moisture is reduced to 5-7 <br />percent, the clean coal is placed on a conveyor that delivers it to the slot storage. <br />The refuse circuit employs a static thickener and disk filters to dewater the smaller material before <br />it is placed in the refuse bin with the larger refuse. The thickener water is disposed in the sealed <br />• 1st longwall district of the D-Seam mine. <br />The preparation plant equipment is enclosed in swell-insulated structure. This, combined with the <br />use of a wet process to clean the coal, eliminates any possible dust emissions. All necessary <br />transfer points between conveyors are also enclosed and equipped with water sprays to reduce <br />dust. All conveyors are partially covered or totally enclosed. <br />111.6.3 Refuse Disposal The preparation plant is expected to produce approximately 700,000 <br />tons per year of coal processing waste at full production. This annual tonnage includes mining <br />dilution that results from mining parting, roof and floor material with the coal. <br />The coal processing waste (refuse) is transported to the refuse disposal area (Map 76) by 35 to <br />100-ton end-dump trucks. Since the refuse is high in moisture, it is allowed to dry and is then <br />spread in layers of about 2 feet and compacted. This layering process continues until the <br />maximum fill height is achieved. Compaction will be performed as specified in Section IV.D.3. <br />• Minor Revision #136 (8/2008) III-2 9 <br />