Experimental study on flotation of milled and classified fine slime and recovery of kaolinite

For enhancing flotation concentrate quality and yield, and making full use of associated coal-measure mineral, a study is made by Linxi Coal Preparation Plant on flotation of fine coal after it is liberated through grinding.Based on study result, a combined process of flotation of milled feed +classification and desliming with cyclone + cyclone underflow flotation + magnetic separation of cyclone overflow for purification and recovery of kaolinite, is proposed.The milled flotation feed with the 0.0374 mm size accounting for 60% of the total is sent sequentially to the φ150, φ75, φ50 and φ10 mm small-conical-angle cyclones for classification and desliming.The underflow materials of the cyclones are then treated through flotation.The overflow of the φ10 mm cyclone is purified through high-gradient magnetic separation.The refined material is finally calcinated at a temperature of 980 ℃.Test result shows the use of the proposed process makes it possible to create not only a favorable flotation condition, improved flotation efficiency and concentrate quality because of the effective separation of fine clay, but also a possibility to recover kaolinite.The application of the combined process proves to be a new approach for comprehensive utilization of ultrafine high-ash coal.