KSEF R&D Excellence: Development of Advanced Simultaneous Fine Coal Dewatering & Reconstitution Process for Energy Recovery and Environmental Protection

The Commonwealth of Kentucky is the third largest coal producing state in the U.S. with an annual output of more than 160 million tons. Recovery of fine coal (minus 0.6 mm), which amounts to. I0-20% ove~all product, is becoming an integrated part of coal preparation plants due to economIcal and. envIronmental concerns. This is often achieved by utilizing the advanced column froth flotatIOn process. The clean coal product contains about 80% water which has to be removed before the product can be sold. However, conventional dewatering techniques are not effective in lowering the moisture and the overall product moisture is often too high to meet industrial requirements. As such, the fine coal and water are stored in slurry impoundments, which recently have been the subject of debates relating to their negative environmental impacts. Therefore, dewatering technology is of critical importance for the Kentucky coal energy industry. The proposed research program is intended to develop an advanced cost-effective technique for simultaneous fine coal dewatering and reconstitution. The innovative process utilizes low-cost high-Btu bitumen-in-water emulsions to reduce fine coal moisture to less than 20% and considerably enhance its handleability simultaneously. New approaches will be investigated to enhance process efficiency by acquiring in-depth understanding of fundamentals. Major efforts will be focused on: a) chemical and surface process characterization of the emulsion by performing spectroscopic studies and conducting measurements of zeta potential, surface tension, viscosity, contact angle, etc; b) identification of the best bitumen and optimum conditions to achieve the lowest cake moisture and/or best handleability; and c) testing the process in vacuum, hyperbaric, and centrifugal filtration. The successful development of the proposed process will increase the competitiveness of the .~entucky .coal energy indu~try, make good use of fine coal as a significant energy source, and mItIgate envIronmental pollutIOn caused by fine coal slurry impoundments.