During coal preparation, a coal refuse of no commercial value is produced and discarded in piles. As rainfall percolates through the piles, acid waters are formed. A feasibility study has been performed on a process producing sulfur from such coal refuse. In this process, limestone and coal refuse are ground, pelletized, and preheated before entering a desulfurizing shaft reactor where a hard, fired ash pellet and an H2S-SO2 bearing offgas are produced. After sulfur, tar, and other gases are removed, the resulting H2S-SO2 gas proceeds to a conventional sulfur recovery plant. Experimental results and economics of this study indicate that the process is a profitable means of minimizing coal refuse pile water pollution. For a sulfur and ash pellet selling price of $20 and $1.50/ton respectively, it is estimated that a coal producer will have a before tax return on investment up to 53 percent for a one MM ton/year plant utilizing an eight percent sulfur refuse. (Author)

"September 1971." "Research conducted by Black, Sivalls & Bryson, Inc., Applied Technology, Pittsburgh, Pennsylvania." U.S. Environmental Protection Agency Contract No. Contract Number: 14-12-929. Includes bibliographical references (page 57).