Centrifugal dry magnetic separation of fine magnetic minerals

Abstract

Dry magnetic separation (DMS) has low selectivity for fine magnetic ores, due to the difficult dispersion of fine particles in the separation process. To address this problem, a novel centrifugal dry magnetic separation (cDMS) method was proposed to enhance the separation efficiency for fine particles. In this investigation, the cDMS mechanism was theoretically analyzed and the cDMS performance for a pure magnetite-quartz mixture was evaluated. Theoretical analysis indicated that the minimum magnetic field force required for capturing magnetic particles is closely related to the acceleration of applied centrifugal field, the angle of separation cone, and the property of material to be separated. During the process, magnetic particles move spirally on the separation cone surface, while non-magnetic ones move out of the cone in parabolic trajectories. Separation results demonstrated that the operating parameters such as magnetic induction, separation cone speed and feed particle size have significant influences on the cDMS performance.