Abstract: The ever increase of the content of coarse in raw coal slime has led to reduced capacity and increased medium consumption of the plant's primary washing system. To tackle this problem, the existing washing system is remolded through the use of 3-cone water-only cyclone in place of the hydraulic classifying cyclone. Practice shows the use of the 3-cone water-only cyclone can not only ensure the ash of combined product is below 8%, but also lead to increase of capacity of the plant's economic performance.