Abstract: The influence of magnetic pulse pretreatment technology on grinding efficiency and separation index of Gongchangling magnetite was studied. Microstructure of samples and dissociation degree of grinding products before and after pretreatment were analyzed by means of scanning electron microscopy and microscopy. The results show that under the conditions of 39.81 kA/m magnetic field intensity and 5 s pretreatment time, the content of -0.043 mm in the grinding products after pretreatment increases by 4.58 percentage points on average; under grinding time of 9 min, and magnetic separation field intensity of 79.62 kA/m, the TFe grade of the pretreated magnetic concentrate increased by 1.16 percentage points, compared with untreated sample , and the iron recovery increases by 1.21 percentage points on average; under the action of magnetic stress produced by magnetic pulse equipment, the bonding strength of different mineral interfaces in the ore decreases, resulting in cracks, which is beneficial for liberation degree increase in grinding process, and ultimately improving the grinding efficiency and separation index of magnetite.

Key words: Magnetic pulse pretreatment, Magnetite ore, Grinding efficiency, Separation index