Interlaboratory comparison of advanced fine-coal beneficiation processes

The Pittsburgh Energy Technology Center (PETC) recently completed three interlaboratory test programs involving 21 developers of advanced fine-coal-cleaning processes. The processes consisted of specific gravity separation (aqueous or heavy-liquid), electrostatic separation (dry), advanced froth flotation, selective agglomeration, and surface modification (gas). The participating organizations received representative samples of Illinois No. 6, Pittsburgh, and Upper Freeport bed coals. They ground them to a size appropriate for their particular process and then treated each coal. Their goal was to produce a clean coal with 2--3{percent} ash while recovering maximum energy. The products were returned to the PETC for analysis and performance evaluation. This paper will discuss the processes involved in the three test programs and present the results of the beneficiation tests. 4 refs., 4 figs., 3 tabs.