Abstract: Octylphenyl ethoxylate (OP) surfactant series was blended with kerosene to be used as collecting agent for flotation of coal slime from crude coal of Tunlan coal mine.Dispersity of separate collecting agent in water as well as contact angle of the refine coal was measured and determined.Results showed that the blends of OP and kerosene display obvious promotion effects on the flotation of coal slime and the blend of OP-4 and kerosene displays better effect than others in the series.As comparing with the same dosage of kerosene singly,the yield of refined coal and ash content of tailing coal increases 11.87 and 17.85 percentage points respectively;as well as the combustible recovery and flotation perfect index,increases 12.91 and 3.12 percentage points respectively.It indicated that the promotion effect is enhanced due to the improvement of diffusion of kerosene in water,and the upgrading of contact angle of the refined coal,which lead to improvement of its hydrophoby.

Key words: nonionic surfactant, octylphenyl ethoxylate, coal slime, flotation, contact angle