Fluidized-bed combustion of dewatered coal washery tailings
Modern coal mines routinely reduce the ash and/or sulfur content of coal to customers` specifications using multistage washeries. Washery configurations are often selected for the particular seam properties and the mining techniques used at a specific mine, as well as the justifiable cost. There is not a single configuration in use for washeries. Also, washeries are in an evolutionary process as improvements are made over time and process steps (hydrocyclones, thickeners, flotation cells, heavy media separation) become accepted within the industry and/or ash and sulfur levels become more restrictive with competition and regulatory changes. Commonly, there are two reject streams from washeries: (1) coarse rejects an (2) fine-sized tailing. Coarse rejects are the large-sized rocks, with some lumps of coal, which do not pass the inlet screen to the washery and are not worth the effort to recycle by crushing. Common sizes are above 2-2 1/2 inches (above 50-60 mm). Coarse rejects are used in site rehabilitation, dam building, and the mixed with overburden or other rock-rich materials for disposal at the mine in spoils piles or previously mined pits.
- OSTI ID:
- 405488
- Report Number(s):
- CONF-951208--
- Country of Publication:
- United States
- Language:
- English
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