Dewatering Ultrafine Clean Coal in a T. H. Filter Press

Abstract

This study demonstrates a low-cost, high-efficiency filter press technology for dewatering minus 150 mm column flotation clean coal products from two coal mines. Pilot-scale in-plant demonstration of this technology at these two locations provided stable, trouble-free operation while achieving an excellent dewatering performance at a high throughput. At one location, filter cakes with residual total moisture contents in the 20-22% range were achieved. At the other location 25-27% residual total moisture contents were achieved.At the second location, lower cake moisture content in the range of 21-25% was achieved with the use of appropriate dewatering aids. For difficult to dewater coals with higher clay contents, the innovative use of hot water during the filtration process was found to reduce cake moisture content by two to three percentage points over the baseline conditions. Engineering economic evaluations indicated that a fine coal product can be produced using column flotation and the filter press at a cost of $5.95=t (dry basis) for one mine. With appropriate blending strategies, annual profitability can be shown to increase by $0.9 million ($US) for this 1.8 Mt=year mine. For the second 2.4 Mt=year mine, annual profitability was projected to increase by $2.5 million ($US).

Screen Bowl Centrifuge Dewatering Process: A Parameteric Study

“…In other words, the slurry temperature was not constant from test to test. Based on the findings from a recent study [15], slurry temperature does play a role in the moisture content of the dewatered product. This phenomenon may have contributed to the scatter in the product moisture data and relatively poor R 2 value.…”

Baseline Testing of a Filter Press and Solid-Bowl Centrifuge for Dewatering Coal Thickener Underflow Slurry

“…When dewatering fine anthracite tailings containing 55% of À25 mm material, which had an ash value of 53%, cake moistures down to 17% were obtained [4]. In another study using a Midwestern U.S. coal, a À150 mm coal flotation product was dewatered to a total moisture content of around 20% [5].…”