微粉煤旋转摩擦电选降灰试验研究

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

为了确定微粉煤旋转摩擦电选降灰试验的最佳操作参数,在分析微粉煤试样密度组成、矿物组成及煤和矿物的摩擦荷电性质的基础上,研究了充电器转速、分选电压以及气流速度等关键操作参数对微粉煤旋转摩擦电选降灰效果的影响,并采用Design-Expert软件中的Box-Behnken试验设计模块对试验参数进行了优化。结果表明:随着充电器转速的增加,精煤产率不断下降,灰分先降低后增加,分选效率先增加后降低。随着分选电压的增加,精煤产率和灰分都呈下降趋势,分选效率不断增加。随着气流速度的增加,精煤产率和灰分先降低后增加,分选效率则不断降低。当充电器转速为5 000 r/min,分选电压为40 k V,气流速度为1.5 m/s时,微粉煤旋转摩擦电选降灰效果最佳,分选效率最高为21.34%。

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 airflow 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 conditions.The results showed that with the increase of charger speed,the concentrate yield decreased constantly,the concentrate ash decreased first and then increased,separation efficiency was opposite; with the increase of separation voltage,the concentrate yield and concentrate ash decreased constantly,the separation efficiency increased constantly; with the increase of airflow velocity,the concentrate yield and concentrate ash decreased first and then increased,the separation efficiency decreased 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 separation efficiency was 21.34%.