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U.S. Department of Energy
Office of Scientific and Technical Information

The effect of fine grinding on the production of superclean coal by flotation

Conference ·
OSTI ID:6343619

Because of the growing need to develop new technology for producing superior quality coals to replace oil and natural gas, the US Department of Energy's Coal Preparation Division is looking at fine grinding and multistage flotation processes to maximize the liberation and removal of sulfur-bearing and ash-forming mineral matter from coal. The beneficiation of micronized coal by froth flotation has long been considered unsatisfactory because of poor product quality and/or poor recovery. However, recent studies have shown that ultrafine coal can be cleaned to very low-ash levels if the appropriate grinding procedure is used to prepare the coal and if a relatively low ash feed is used. For example, wet grinding assures a much lower ash froth concentrate than does dry grinding. In addition, work now in progress suggests that superclean products of high yield can be obtained by a combination of coarse coal cleaning or rougher flotation, followed by wet grinding and reclining by second-stage and third-stage coal flotation. For example, by a combination of rougher flotation, wet grinding of the rougher concentrate, and two-stage coal flotation of the wet-ground product, an Upper Freeport bed coal sample was cleaned from 26% ash and 1.1% pyritic sulfur to 4.5% ash and 0.1% pyritic sulfur. 4 refs., 7 figs., 8 tabs.

Research Organization:
USDOE Pittsburgh Energy Technology Center, PA
OSTI ID:
6343619
Report Number(s):
CONF-850982-4; ON: DE87011814
Country of Publication:
United States
Language:
English