Abstract: Flotation of deslimed feed can lead to reduction of not only consumption of reagent, but also contanmination of concentrate by fine slime. Based on theoretical calculation and analysis, a study is made of the technical feasibility of having flotation feed pre-deslimed with cyclone classifier, together with an economical analysis of such a process applied at a 3.00 Mt/a coal Preparation plant. Study result shows that with the use of a small-diameter cyclone classifier, the < 0.074 mm fines can be successfully removed from flotation feed, and the use of the process can create a remarkably favorable economic result due to improvement of flotation feed and flotation performance.