Abstract: To increase the index of hematite flocculation flotation， magnetized water，magnetized pulp and magnetized starch were used to flocculate and settle hematite. Effects of magnetization treating on flocculate were investigated. The results show that all of the three magnetization modes can improve the flocculation settlement rate of oolitic hematite. The results of optical microscope analysis showed that it can be clearly seen that the floc size after the magnetization treatment is larger and more compact than that of the unmagnetized，at the same time， transparent quartz particles dispersed around the floc were observed， indicating that the magnetization treatment can significantly promote the selective flocculation of micro-grained hematite. Under the three magnetization modes of magnetized water，magnetized ore pulp，and magnetized starch，the surface potential of hematite particles decreased with the increase of magnetization time， and the variation trend of the Zeta potential was consistent with that of the sedimentation rate of oolitic hematite under different magnetization conditions. The flocculation mechanism of the fine-grained hematite after treated by three magnetization modes is in line with the extended DLVO theory.The flocculation mechanism is: the magnetization treatment can reduce the Zeta potential of the hematite in varying degrees，thereby reducing the double electrical layer repulsive force and potential energy barrier among the fine-grained hematite particles.

Key words: Oolitic hematite, Magnetization treatment, Flocculation behavior, Zeta potential