A final report is presented on studies conducted to develop washability data on coal mined primarily for use in power generation. The studies attempted to extend the washability data to finer sizes of coal and to evaluate coal cleaning methods and techniques for removing pyritic sulfur from the fine-sized coal. The investigation was made into the pyrite liberation and removal characteristics of U. S. coals when pulverized to two fine grinds of interest; the 30 mesh x 0 size, and each coal's as fired, or pulverized coal grind. Detailed work was undertaken to determine the potential of fine cleaning for preparing a concentrated grade of pyrite, as removed from the fine coal, in quantities commensurate with the total amount available for removal. In line with the total seam utilization concept, where only the obvious refuse would be discarded, the use of the intermediate fractions lying between the clean coal and the high grade pyrite was studied. (Author)