Abstract: This paper assessed the floatability of Lingshi coal slime and analysed the reason of its poor floatability.Using the technology of emulsifying diesel,this experiment took laboratory cyclonic Static microbubble flotation column as the chief separation equipment to deal with the coal slime.The experiment results shown that this technology could reduce the consumption of collector and improve the recovery rate of the clean coal.As an efficient way of treating the hard-to-float coal slime,this technology consumes fewer reagents and could achieve good flotation results,which could improve economic benefit significantly.