Abstract: In order to understand flotation feasibility of low-rank coal,taking low-rank coal slime from Shuozhou area in Shanxi province,Qitaihe in Heilongjiang province,Erdos in Inner Mongolia,Xunyi and Shenmu in Shaanxi province,flotation test is conducted by collecting agent suitable for surface properties of this coal. The result shows that clean coal with 13%-20% content of ash is obtained by flotation of the low-rank coal with 24%-50% content of ash; the recovery of combustibles is up to 60%-85%,with an increase of 3. 35-10. 04 MJ/kg in calorific value. Meanwhile,it is a proposal for optimizing flotation technology of this coal to reduce consumption of agent and improve selectivity of flotation.