Basic Study on Mineral Removal from Coal-The Influence of Mineral Distribution and Size of Pulverized Coal on Characteristics of Mineral Removal

Abstract

The influences of mineral content, mineral distribution, and the size of pulverized coal on the characteristics of mineral removal from coal were investigated in order to develop an efficient mineral removal method. The influence of these factors on the characteristics of mineral removal from coal was evaluated using a specific gravity separation method. The influence of mineral content on the characteristics of mineral removal was found to be considerable at a mineral content lower than 10% by weight, while conversely became weak at a mineral content exceeding 10%. The mineral removal ratio decreased as the particle size of minerals in coal became small. On the other hand, the shape of the minerals was found to have no effect on removal. In addition, the mineral removal ratio increased with the decreasing particle size of pulverized coal. However, it was difficult to separate between mineral matter and organic matter in coal containing fine mineral particles with sizes under 20 µm. These results showed that the characteristics of mineral removal from coal were influenced by the mineral content, the particle size of the minerals, and that of the pulverized coal. Thus, it was found that the choice of a suitable pulverization method for mineral distribution in coal is quite important when developing an effective method of removing mineral matter.