Magnetic entrainment mechanism of multi-type intergrowth particles for Low-Intensity magnetic separation based on a multiphysics model

Abstract

Wet low-intensity magnetic separation (LIMS) is used in the magnetic separation of ferromagnetic minerals. The performance of the separation is controlled primarily by the internal flow in the separator, governed by the process and machine settings. However, a very important factor has been usually ignored in the LIMS process, namely the behavior of the intergrowth particles. The detailed influence of the various condition parameters on the behavior of the particles with different characteristics in LIMS is still not clear. In this study, a two-way coupled multiphysics model was used to simulate the dynamic capture process of the multi-type intergrowth particles and its impact on the performance of LIMS separation. All predictions indicate that the operating parameters and particle properties affect the capture behavior of intergrowth particles, which significantly affects the separation performance of the LIMS. Intergrowth particles play an important role in the process of LIMS. Additionally, the capture time for the intergrowth particles of different particle sizes and liberation degrees to reach the drums’ surface from the initial location are different. Because the capture time of the coarse intergrowth particles is much shorter than that of the ultrafine pure magnetic particles, the coarse particles will preferentially accumulate on the drum to cause a magnetic entrainment phenomenon. The phenomenon of magnetic entrainment facilitates the recovery of intergrowth particles. In LIMS, however, for a high grade and recovery magnetic product, intergrowth particles and high liberation is necessary and excessive grinding of the particles should be avoided.