Abstract: Overstocking of sluggish sales of high-ash coal slime and environmental protection are the problems facing Lyulin Coal Preparation Plant. To tackle the problems, work is made on the optimization of the existing tailings product reconcentration process. Practice shows that by resorting to pre-removal of fines from refuse magnetic tailings plus, thickening and reflotation process, the middlings product can be effectively recovered. By using this process, the rate of middlings reclaimed is up to 40% with a rise of yield of middlings by 2% and an increase of tailings ash to over 75%, which can be discarded as solid waste. This can not only enhance the rate of utilization of coal slime but also create a favorable economic benefit for the plant.