Abstract: The plant is facing the challenge that the ash of cleaned coarse slime and the ash of flotation concentrate are all higher than that of the clean coal produced by the heavy medium separation system, and the heavy medium system has to drop the ash of its clean product to an excessively low level. In order to tackle this problem, renovation of the plant's cleaning system is made through the sue of laminated fine screen to make in-depth desliming and ash reduction of the clean coal product of TBS and the addition of secondary flotation system to reduce the ash of concentrate product. The renovation work has made it possible to lower the ash of the product of TBS and the ash of flotation concentrate to a qualified range, eliminate the requirement for the heavy medium separation system to further lower the ash of its clean coal product, increase the recovery of clean coal, and yield a maximum economic benefit for the plant.