WO1991006618A1 - Coal beneficiation and utilization ...
A method of beneficiating a particulate carbonaceous material such as coal, including formation of a slurry of the material in an aqueous salt solution. The slurry is separated in a cyclone into a low-density fraction and a high-density fraction with the low-density fraction having particulate carbonaceous material with a lower sulfur content and lower ash content than the particulate ...