Practice of renovation of coarse slime separation process at Lvliangshan Coal Washery

The cleaned coarse slime is found to be a bit too high in ash.For solving this problem,an analysis is made of the causes and existing processing conditions together with a general survey of the stateof-the-art of the technologies currently available for the separation of coarse slime both at home and abroad.Based on the result of investigation,it is decided to treat the coarse slime with a separate 3-cone water-only cyclone washing system.Compared with the classifier cyclone originally used,the use of the 3-cone cyclone has led to an increase of the yield of overflow by 13.06 percentage points,a drop of overflow ash by 2.60 percentage points and an increase of underflow ash by 12.03 percentage points,enabling,as a result,more clean coal to be recovered.As evidenced by field operation over the past 2 more years,the performance of the renovated washing system has reached or surpassed the designed expectations in various technical aspects,this bringing about a favorable economic and social result.