Effect of Magnetic Field in Magnetic Separation Column on Particle Separation Process Based on Numerical Simulation

Abstract

The magnetic field in the magnetic separation column is a key factor in determining the separation process of mineral particles. The limited data points and low accuracy of measurement of the magnetic field cause difficulty in estimating the relationship between the magnetic field and particle separation process. A calculation model of the magnetic field of the magnetic separation column was proposed in this study to explore its effect on the particle separation process. The calculation model was established by creating the magnetic system model, dividing the mesh, setting the boundary conditions, and applying the load by using the finite element method. The effect of the magnetic field on the particle separation process was analyzed according to the transient equation of motion. Results demonstrate that the magnetic field strength in the axial direction is in good agreement with the theoretical value. The accuracy of calculation model is verified. The magnetic field gradient is maximal near the upper edge of excitation coil in the magnetic separation column. The magnetic field gradient is 466.8 kA/m per meter when the excitation current is 4 A. The particles form fluxes and accelerate downward. The fluxes begin to disperse and decelerate downward due to the sudden direction change of the magnetic field gradient below the center plane of the coil. The gangue and intergrowth are separated out from the fluxes under the action of water flow. High-grade concentrate is obtained. The proposed model provides evidence for the optimization of the magnetic system in the magnetic separation column.