Abstract: In this paper, four kinds of collectors are used as a collector in the flotation of difficult floated coal slime with high content fine clay, and the related mechanism was analyzed. The progressive release experiment, contact goniometer, micro calorimeter and infrared spectroscopy were applied to study and compare the collector performance of the four different collectors，and the adsorption mechanism of coal and different collectors was discussed. The results indicate that the wetting heat , contact angle, combustible recovery and the flotation activity of the four collectors decrease in the order as follows:1#collector＞ 2#collector＞ 3#collector＞kerosene collector. The infrared spectroscopy demonstrated that the role between collectors and coal can be considered as physical adsorption，the radical group ＞C=O of collectors could increase its collector performance.

Key words: collector, difficult floated coal slime, floatation, performance