Coal Age

MAR 2013

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coal preparation continued other industrial customers that specifically require washed coals." Beechwood Coal is able to market a customized quality of coal by blending raw coal processed through the Accelerator with washed coal. This processing method allows Beechwood to take non-marketable coals and turn them into higher quality, marketable coals that meet or exceed their customers' required quality and size specifications. "We do not use a crusher to crush everything," Ritchie said. "The Accelerator processed coal is of higher quality than just crushed coal. We only wash as much coal as needed to blend with Accelerator processed coal to meet customer requirements. This reduces the amount of washed coal required for blending and helps keep our overall costs down." The Blending Process The impact breakage in the Accelerator is adjusted by variable speed controls to selectively fracture the coal. 36 www.coalage.com Before any coals are processed, an outside lab samples the raw coals and washed coal. The analytical data and weight tickets from the truck scale deliveries allow Beechwood to determine the appropriate computerized raw, raw with raw, and raw with washed-coal blends needed to meet customer specifications at the lowest cost. Sampling is repeated thereafter to validate that the processed coal meets customer quality specifications and requirements. "We used to have our own lab to analyze coals, but now it is more cost effective and required by our customers to have an ASTM independent, certified lab validate the coal quality," Ritchie said. "We pay our coal suppliers on the delivered analysis and receive payment from our customers based on their certified 'as received' analysis." For each customer order, the delivery weight tickets and lab analysis are used to determine the types and amounts of coals to be selected from the specifically marked coal stockpiles. A frontend loader operator systematically dumps buckets of the selected coals into the 150-ton capacity blending bin. The 150-ton bin has a 10-inch square grizzly that can also receive direct delivery by truck. The bin and grizzly were designed to support the weight of a front-end loader, which can break up any oversized coal chunks through the grizzly into the bin or to scrape off large rocks. The blending bin was intentionally designed with approximately 70° sloped sides and lined with stainless steel to prevent material from sticking to the bin sides or plugging the bin. A vibrating feeder under the bin delivers a consistent and controlled feed of material at a variable feed rate ranging up to 600 tph onto a 36-inch decline conveyor. The decline conveyor discharges onto an 8- x 16-ft, single-deck Tabor screen, located at the second-tier elevation. This screen has 2-inch stainless steel cloth openings on the upper 8-ft section and 1-1/2-inch openings on the lower screen section. Depending on the coal seam or seams being blended to be processed, up to 70% of the friable and sized coal may pass through the screen directly onto the collecting conveyor below. The 12- x 2-inch oversized material vibrates over the bottom section of the screen, discharging into the Accelerator. The impact breakage in the Accelerator is adjusted by the variable speed controls to selectively fracture the coal to a 2inch x 0 sized product while minimizing breakage of the denser, harder impurities. Oversized shale partings, pyritic rock and March 2013

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