Abstract: According to the problem of high production pressure on slime filtration system which caused by high content of gangue and the gangue very easy to sliming,Banji coal preparation optimized the coal slurry thickening system using two stage thickening and two stage recovery process,and using the solid bowl centrifuge recovering coal slime from first thickening stage.These measures reduced the pressure on the coal slurry treating system,also obtained good economic benefit.