Technical study of the fine coal cleaning and recovery system of Binhu Coal Preparation Plant

The loss of coarse coal particles in flotation tailings is one of the factors causing the difficulty to obtain a low-ash clean coarse slime product through the coarse slime recovery system of Binhu Plant. To tackle the problem, following a technical checking of the clean coarse slime classifying cyclone, high-frequency vibrating screen, dewatering centrifuge and flotation column, an analysis is made of the operating effects of such equipment. Result of analysis shows that the underflow of the cyclone is relatively high in ash making it impossible to obtain a low-ash clean product; the high-frequency screen is low in desliming efficiency with heavy presence of unretained oversize particles in screen underflow; and the flotation column is rendered unable to operate in an optimal state because of the high proportion of coarse particles in feed. It is proposed to add coarse slime cleaning equipment, switch to the use of stacked high-frequency vibrating fine screen in place of the existing high-frequency screen, exercise stricter control of flotation feed, and strengthen flotation column maintenance management.