Abstract: In order to realize the efficient utilization of gasification fine slag as resource, the physical and chemical properties analysis, particle size screening and carbon ash separation experiments of gasification fine slag from an enterprise in Ordos area of Inner Mongolia were carried out. The results show that the fine slag is mainly composed of SiO₂, CaO, Al₂O₃, Fe₂O₃ and unburned carbon, but also contains a very small amount of K₂O, Na₂O, TiO₂ and so on. The sample mainly contains Quartz, Calcite, Katoite and Moissanite, the average specific surface area is 0.64 m²/g. The sieve flotation experiment showed that the dominant size of the gasification fine slag was 0.075–0.5 mm. After screening, the flotation effect of the fine slag with a particle size below 0.075 mm was better, while the flotation result of the fine slag with a particle size between 0.25 mm and 0.5 mm was worse. Analysis of different influencing factors showed that the optimal flotation process parameters of the fine slag were as follows: slurry concentration of 60 g/L, foaming agent concentration of 10 kg/t, collector waste oil consumption of 15 kg/t flotation time of 10min, and aeration of 300 L/h. In addition, low concentration calcium chloride can inhibit flotation, and the flotation results can be improved when adding 0.2 mol/L.