Abstract: In order to increase the clean coal yield in Wangfenggang coal preparation plant,from the aspects of particle size composition and floatability of slime,the comprehensive test and analysis was done on the feed slime in that coal preparation plant,the flotation reagent selection test also conducted.The tests result show that when the concentration of the slime is 100 g/L,and take diesel oil as collector ZA21 as a foaming agent,and dosage is 800 g/t and 60 g/t reapectively,the flotation result is best.Using the diesel and ZA21 as combined agent,the ash reduction effect is better than only using of CMC,and affordable,it is economical and practical,effectively simplified the flotation process of Wangfenggang coal preparation plant.