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U.S. Department of Energy
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Coal-pyrite flotation in concentrated pulp: a pilot plant study

Technical Report ·
OSTI ID:7218203

The Federal Bureau of Mines coal-pyrite flotation process has been modified to produce a concentrated final clean coal slurry underflow that could be dewatered more effectively by filtration or centrifugation. This change was accomplished by redesigning the Bureau's two-stage flotation pilot plant facility and running the second-stage flotation step with undiluted or only partially diluted first stage coal froth concentrate. Substantial sulfur reduction could be achieved by flotation with undiluted pulp but some dilution is recommended for maximum selectivity. For example, coal-pyrite flotation in slurry of 25 percent solids yielded clean coal products analyzing as low as 0.7 percent pyritic sulfur and froth reject products containing slightly over 3.0 percent pyritic sulfur. In comparison, coal-pyrite flotation with pulp diluted to about 12.5 percent solids yielded clean coal containing as low as 0.4 percent pyritic sulfur and froth reject of 5.6 to 6.7 percent pyritic sulfur. Despite the need for some dilution, it was concluded that excellent coal-pyrite flotation selectivity could be achieved without diluting to 6 or 7 percent solids as done in the earlier work. Thus the economics of coal-pyrite flotation would be improved by easing clean coal dewatering problems and by reducing second-stage flotation cell volume requirements.

Research Organization:
Bureau of Mines, Washington, DC (USA)
OSTI ID:
7218203
Report Number(s):
BM-RI-8239
Country of Publication:
United States
Language:
English