Abstract: The trouble with the TBS system of Dongqu Coal Preparation Plant is that it operates with ageing equipment,an unstable supply of feed and the presence of coarser particles in overflow of thickening cyclone and underflow of sieve bend due to wear of the two process equipment. To cope with this situation,work is made on process optimization,and electromagnetic high-frequency vibrating screen is used instead to recover the concentrate. After process optimization,the TBS system now works with a uniform and stable supply of feed and the loss of coarser particles in tailings is effectively reduced,much helpful to the improvement of fine coal flotation performance.