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Microwave drying of fine coal.
Worldwide, an increasing number of coal preparation plants are drying fine coals and gaining a variety of benefits. Transport costs can be reduced; heat loss during the burning process can be reduced; freezing problems may be avoided. Microwave technology has been one of the potential methods studied by the U.S. Bureau of Mines as part of a research program into drying fine coal. Efficiency for all tests was 77 pct, which compares very favorably with conventional drying techniques, particularly since less energy was needed to dry the coal. Since water tends to readily absorb microwave energy and coal does not, microwave energy selectively focuses on the moisture content in the coal, drying it far more efficiently than conventional drying processes. Results showed that water absorbs microwave energy significantly, but coal does not. Secondly, microwave energy heats only the water, unlike existing drying methods, which heat both water and coal. Finally, the method was found to be energy efficient and minimized the generation of fugitive dust.
OP; Journal Article
Issue of Publication
Mine and Quarry
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division