Evaluation of an Underground Separation Device of Coal and Gangue

A novel underground device for separation of coal and gangue was introduced. Mixed materials of coal and gangue from five coal mines were crushed and tested using five rotor speeds. The results showed that separation of coal and gangue underground can be executed effectively under certain conditions: the greater the hardness difference between coal and gangue the better the separation. According to the regression analysis of the results, there was a close linear relationship between the lost coal rate, mixed gangue rate, hardness of coal and gangue, and the rotor speed. The lost coal rate increased as the hardness of coal increased and decreased as the rotor speed increased. The mixed gangue rate decreased as the hardness of gangue increased and it increased as the rotor speed increased. The effectiveness of separation of coal and gangue can be evaluated using to the regression equation obtained from the experiment.