Improvement of coal washing efficiency and economic performance of Wuju Coal Preparation Plant through quality control of raw coal: approaches and practice

Wuju plant’s coal washing efficiency and quality of products are adversely affected because of deterioration of run-of-mine coal and delay of raw coal quality control. Based on analysis of various process links of underground coal mining, coal haulage, coal washing, etc., multiple measures are taken, including, among others, reduction of mining heights, preremoval of gangue from coal underground using intelligent TDS dry separator, execution of automatic coal sampling and preparation online monitoring of ash of coal, as well as practice of information-based digitalized management mode. With implementation of such approaches, the plant is now possible to exercise strict control of coal quality and give early warning in case of any discrepancies, the plant is now possible to reduce the ash of raw coal by 15 percentage points on average, keep fluctuation ash of clean coal below 0.3 percentage points, and obtain a yield of clean coal of over 35%. Implementation of the comprehensive coal quality control approaches has led to curtailment of operating cost, less environmental pollution, and improved economic and social benefits. The work made in the paper may serve as a reference for other plants facing similar problems.