NIOSHTIC-2 Publications Search
Column Flotation of Coal With Fluorosurfactants: Final Report.
Work Performed for U S Dept of Energy Under Contract A122- 88pc88561 Doe/pc/88561-t1 1989 :116 pages
The Bureau of Mines evaluated column flotation methods, coupled with novel fluorosurfactant collectors, for the selective flotation of fine coal from pyritic sulfur and mineral matter. For flotation feeds of both minus 100- and minus 400-mesh Lower Kittanning seam coal samples, anionic and nonionic fluorosurfactants were no more effective than mibc alone; however, flotation with nonionic fluorosurfactants did not increase total sulfur and ash contents as sharply as mibc systems. In general, total sulfur and ash rejection from this coal were better for nonionic systems than anionic systems, probably because anionic fluorosurfactant precipitated in hard water and coated pyrite and mineral matter particles indiscriminantly, reducing selectivity. Changing feed size to minus 400-mesh did not improve flotation selectivity in nonionic systems. Similarly, with mibc systems total sulfur and ash contents were not reduced over that achieved in minus 100-mesh feet tests, except when a pyrite depressant, potassium monopersulfate, was used in conjunction with the mibc frother. The most promising concentrate from this study was produced using 20 lb/st monopersulfate and 1.8 Lb/st mibc frother to float minus 400-mesh feed: a 2.3% Total- sulfur and 4.1% Ash-content concentrate with 71% coal yield.
Work Performed for U.S. Dept. of Energy Under Contract A122- 88pc88561 Doe/pc/88561-t1, 1989