Abstract: Following a comparison of the two processes for treating respectively dislimed and undislimed raw coal,the paper elaborates on the advantages and disadvantages of each process in terms of clean coal yield,organic efficiency,rate of qualified product,and medium,oil and power consumptions.Based on the result of an in-depth study of all of the factors involved,the process for treating undislimed raw coal using gravity-fed 3-product H.M.cyclone is proposed.Practice shows the use of the system can lead to a higher yield of clean coal at a lower operating cost,and the system is simple in process and low in investment on equipment.