Abstract: Due to the high grade of flotation tailings that caused by the low recovery of fine particles in floatation process of Qidashan Iron Mine, Petroleum Sulfonate was used as collector and flocculating agent to make the shear flocculation and flotation tests on Qidashan magnetic separation concentrate in laboratory test.The results indicated that the optimum conditions for the shear flocculation and flotation are the grinding fineness of -0.037 mm 85%, pulp pH at 3, the dosage of Petroleum Sulfonate as 5 kg/t, water glass of 300 g/t, stirring intensity of 2 200 r/min, and shear time at 6 min.Under this condition, a good iron concentrate index with Fe grade of 66.80% and Fe recovery of 95.93% and Fe grade of tailings 5.03% only were obtained firstly by the shear flocculation of magnetic separation concentrate, then following by one closed-circuit flotation process of one-roughing, one-scavenging and three-cleaning.

Key words: Magnetic separation concentrate, Shear Flocculation, Flotation, Petroleum Sulfonate