Abstract: Abstract Taking theΦ1 050 mm×3 000 mm wet drum low intensity magnetic separator in roughing operations in Panzhihua Midi concentrator for example, the recovery of magnetic minerals with different particles was predicted by using the traditional theory of magnetic separation (the precondition of magnetic mineral particles be recycled is that the magnetic force is greater than the sum of gravity and water resistance which acting on particles). And the relative error between the predicted result and the real data reaches maximum 58.05%. Thus, it queries about the applicability of the traditional magnetic separation theory. Further study on magnetic dipole model is made. Results show that force between magnetic dipoles applied on magnetic particles in the magnetic field is much greater than the gravity, water resistance and magnetic force. Additionally, magnetic particles in magnetic field reunite into magnetic coagulation within 0.02 s which has an important impact on process of low intensity magnetic separation due to the force between magnetic dipoles. Without considering the effect of magnetic dipole force, the traditional magnetic separation theory produces large error when predicting the effect of the low intensity magnetic separation. The research results provide new reference for designing magnetic separation equipment.

Key words: Low intensity magnetic separation, Traditional theory of magnetic separation, Force between magnetic dipoles, Magnetic coagulation