Research on liberation features of high ash content and difficult to wash coal slime

Take the high ash content and difficult to wash coking coal slime of Qianjiaying colliery as the research object,based on the coal quality analysis,conducted the liberation test and investigated the effect of different grinding condition on liberation of coal.The tests result show that the mainly hosted minerals in the slime are kaolinite and quartz;the higher fine size content the higher the ash content;in higher intermediate density content slime,the coal and minerals are majorly existed as intergrowth form;the minerals liberated by ball mill is easy than rod mill,but uniformity of the particle distribution of ball mill is worse than that of rod mill;the biggest factor effects the clean coal yield is grinding time,and the biggest fact effects the ash content of clean coal is rotary speed of mill;the pore quantity produced during the grinding of ball mill is more than rod mill,that presents the efficiency of ball mill is higher,which in accordance with sieving result.