Experimental study on reflotation of flotation tailings

The cake product of the tailings filter press of Qianjiaying Mine Coal Preparation Plant is selected as the object of study. Analysis of size and densimetric consist of the tailings cake indicates that it is predominantly in a size of -0.045 mm with a considerably high content of high-ash fine slime. As shown by the washability curve drawn according to its density consist data, the tailing cake has a moderate washability—a property warrantable to making reflotation treatment. As evidenced by sequential flotation test and washability data, only through primary flotation process, an up-to-standard concentrate product can hardly be obtained because of the relatively poor flotability of fine coal, low flotation accuracy and the difficulty in making process control. Based on the result of test on flotation parameters, timed-release analysis, multiple flotation and flotation rate, it is observed that; through secondary flotation of the tailings at an agent dosage of 0.8 kg/t, a concentrate product with an ash of around 17% and a yield of > 35% can be obtained; and through tertiary cleaning flotation process, the ash and yield of the concentrate product obtained are respectively 12% and over 20%. It well demonstrates the value of the tailing product for the recovery of combustible materials.