Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly technical progress report 11, April--June, 1995

The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope includes laboratory research and bench-scale testing on six coals to optimize these processes, followed by design, and construction of a 2-t/hr process development unit (PDU). The PDU will then be operated to generate 200 tons of each of three project coals, by each process. During Quarter 11 (April--June, 1995), work continued on the Subtask 3.2 in-plant testing of the Microcel{trademark} flotation column at the Lady Dunn Preparation Plant with the installation and calibration of a refurbished 30-inch diameter column. The evaluation of toxic trace element data for column flotation samples continued, with preliminary analysis indicating that reasonably good mass balances were achieved for most elements, and that significant reductions in the concentration of many elements were observed from raw coal, to flotation feed, to flotation product samples. Significant progress was made on Subtask 6.5 selective agglomeration bench-scale testing. Data from this work indicates that project ash specifications can be met for all coals evaluated, and that the bulk of the bridging liquid (heptane) can be removed from the product for recycle to the process. The detailed design of the 2 t/hr selective agglomeration module progressed this quarter with the completion of several revisions of both the process flow, and the process piping and instrument diagrams. Procurement of coal for PDU operation began with the purchase of 800 tons of Taggart coal. Construction of the 2 t/hr PDU continued through this reporting quarter and is currently approximately 60% complete