Abstract: When the oil gas produced through evaporation of hydrocarbon oil passes through the inlet of flotation column′s air bubble generator, oil-coated bubbles are generated.Result of oil-coated air bubble flotation of low-rank fine coal indicates that by using this process, a remarkable flotation result can be achieved because oil-coated bubble is high in collecting capacity and selectivity.Industrial application of the technology for flotation of low-rank fine coal with flotation column can lead to reduction of consumption of collector, higher stability of foam layer and improved separation indices.Application of the technology for upgrading of low-rank fine slime proves to be a new approach for utilization of the low-rank coal slime resource.