Abstract: Based on many oxygen- contained functional groups on low rank coal surface,poor hydrophobicity and slime hard to be floated problems,under lab conditio n,an oil- bubbles separation system was designed. With the experiment study,the paper discussed the feasibility of the low rank coal upgrading with slime oil- bubbles float ation. The conventional floatation experiment study showed that when the kerosene dosage was low,the recovery rate of the combustible liquid could be low and he floatati on index would be poor. Only when a large dosage of the kerosene,as 100 kg 1 t was added,a good floatation index could be obtained. The oil bubbles prepared with the hy drocarbon oil flash evaporation technology applied could effectively separate the low rank coal of the slime,the consumption of the collectors could be highly reduced and t he floatation index would be good. When the collector quantity was 2. 5 kg 1 t,the clean coal production yield of the slime in Daliuta Mine would be 82. 38% and the ash con tent would be 8. 26%. The clean coal production yield of the clean coal in Shigetai Mine would be 69. 28% and the ash content would be 11. 14%. The oil bubbles floatation technology applied to the floatation and upgrading to the low rank coal of the slime could provide references to the discovery on resource utilization of low rank coal of the slime.