Improved coal mining economics using near-face deshaling

Coal extraction typically results in the recovery of pure rock that ranges from small to very large quantities, depending on seam thickness, existence of above-seam draw rock or in-seam partings and other characteristics. The removal of pure rock may allow for the recovery of three times the amount in middling coal particles, which has significant economic benefits. In an industrial example, a 150% increase in revenue was realized from deshaling a low-ash, run-of-mine coal and then blending it with a processed clean coal product. Deshaling is the process of removing relatively pure rock from coal, which normally involves a high-density separation in a gravity-based process. The removal of the relatively pure rock near the point of extraction has the potential to further enhance the economics of an operation due to reduced materials handling and refuse storage costs.