Abstract: Diesel oil in common use as a collecting agent in flotation process is a kind of nonrenewable hazardous chemical product. Therefore, seeking a new-type collecting agent for replacing diesel oil is of great significance for effecting green flotation process. For exploring the feasibility of using coal-based synthetic oil as a collector in slime flotation, three intermediates material produced using Fischer-Tropsch process by Lu'an Coal-based Oil Company are selected for use as collecting agents, and through emulsification at different oil-water ratios using Span 80 and Polysorbate 80, an optimum 3^# oil sample is prepared. Based on stability and microscopic analysis of emulsified collectors, the effect that can be obtained in flotation process with the emulsified agents are investigated through flotation test and FTIR analysis. Study results shows that among the crude oil collectors, the 3^# oil is the best in effect with the yield of flotation concentrate product being only 1 percentage point lower than the case of using diesel oil; among the Span series and Tween series emulsified collectors prepared with 3^# oil, the latter series exhibits a best stability and can stay unstratified within one month; and among the Tween series, the use of collector emulsified at an oil/water ratio of 4∶6 can lead to a best flotation results with reduced consumption of the agent.