Optimization of process parameter of tribo-electrostatic separator for high ash non-coking coal preparation using response surface methodology

Tribo-electrostatic separation of low-grade non-coking coal with 39-41% ash was optimized using response surface methodology at 50 kg h(-1)feed rate. The petrographic and SEM-EDAX analysis reveals that coal has difficult liberation characteristics. The optimum condition to minimize the ash content of the coal was 20% relative humidity, 120 s tribo charging time, and 24.75 kV DC voltage. It is possible to achieve 32.7% clean ash coal with 59% yield from a 41% feed ash coal. The combustible recovered at these conditions was 67.4%. The experiment results corroborated well with the estimated value of 9% ash reduction from the coal.