Experimental study on ash reduction of fine coal by rotary triboelectric separation .

In order to obtain the optimum operating parameters of fine coal rotary triboelectrostatic separation, the fine coal characteristics of density composition, mineral composition and tribocharged between coal and mineral were analyzed.The influences of key parameters including charger speed, separation voltage and airflo W velocity on the ash reduction of fine coal was studied.A Box-Behnken experimental design module in Design-Expert software was used to optimize the experimental C onditions.The results showed that with the increase of charger speed, the concentrate yield decreased constantly, the concentrate ash decreased first and then increas ed, separation efficiency was opposite; with the increase of separation voltage, the concentrate yield and concentrate ash decreased constantly, the separation efficienc y increased constantly; with the increase of airflow velocity, the concentrate yield and concentrate ash decreased first and then increased, the separation efficiency decr eased constantly. The optimal ash reduction effect was achieved with charger speed of 5 000 r/min, separation voltage of 40 k V and airflow velocity of 1.5 m/s, the sep aration efficiency was 21.34%.