Abstract: The coarse slime treatment system currently used at Liangbaosi Plant operating with the problems of being low in separation efficiency and yield of clean product. Based on analysis of the problems encountered, work is made on technical transformation of the system. The work made includes, among others, dilution of the feed of TBS separation with make-up water and introduction of the 3-mass high-frequency vibrating screen to replace the vibrating mesh sieve bend. Through the technical transformation, the cleaned coarse slime product can see a sharp reduction of ash from 13.39% to 8.32% and an increase of its yield by a margin of 5.1%, and there is no need for the heavy-medium separation system to reduce the ash of its clean coal more than necessary, yielding as a result a favorable economic result for the plant.