The THFP provided excellent dewatering performance for de-watering a nominally -100 mesh fine coal flotation product from two Illinois coals. Low moisture contents and cycle times under 10 minutes were achieved. For the Illinois No. 6 seam coal, 20 - 21 percent total moisture contents were achieved at a high throughput. These moistures compare favourably even with the screen bowl centrifuge product dewatering the +100 mesh coal. For the Illinois No. 5 seam coal, 26 - 28 percent total moisture contents were achieved also at high throughput. The higher moisture content obtained from this coal is attributed to the presence of mont-morillonitic clays in this coal as well as the higher inherent moisture in this coal. Addition of coarse spiral product (1 mm x 100 mesh) to the fine coal flotation product provided improved dewatering characteristics. Moisture content reductions of 2 - 3 percent were documented. In-plant testing of a mobile column flotation and dewatering circuit provided excellent separation and dewatering performance with trouble free and stable operation. Based on the in-plant test results, full scale implementation flowsheets were developed and engineering economic analyses were conducted. For the Illinois No. 5 seam coal mine, an increase in profitability by US dollar 900,000 per year has been projected through the implementation of the technology described in this paper.
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