Question: In a mechanical coal-washing process, a portion of the inorganic !ulfur and ash material in the mined coal can be removed. A feed stream to the process consists of 73% coal, 11 % ash, 11 % sulfur, and 5.0% water (to suppress dust). The clean coal side of the process consists of 88% coal, 6.0% sulfur, 3.0% ash, and 3.0% water. The refuse side consists of 32% sulfur, with the remainder being ash, coal, and water. If 8.0(101) metric tons per hour of clean coal is required, determine the feed rate required for the mined coal and the composition of the refuse material.