Numerical simulation study on the process configuration of industrial wet low-intensity magnetic separators

The process configuration of industrial wet low-intensity magnetic separators (WLIMS) employing different tank designs significantly influences the separation efficacy of magnetite. To evaluate this effect, a validated multiphysics model is employed to simulate roughing – concentration and roughing – scavenging configurations comprising co-current (CC), counter-rotation (CTC), and counter-current (CR) separators. In roughing – concentration processes, the concentrate grades are similar (differing by at most 1.17%), but using a CTC separator as the concentration increases recovery by 4.62%–4.66% compared with a CC unit. Furthermore, the separator type exhibits distinct size-dependent selectivity: the CC separator favors the recovery of −74 μm particles, whereas the CTC separator is more effective for +100 μm particles, and both achieve comparable recoveries for the 74–100 μm fraction. In roughing – scavenging processes, a CR-type separator yields higher recoveries across all size fractions, with particularly pronounced improvements for fine particles. Validation against industrial plant data shows good agreement: relative errors for concentrate grade and recovery are 1.68% and −2.28%, respectively, while the grade and recovery errors for most particle size fractions remain within ±7%. The results demonstrate that the model accurately predicts separation outcomes and can guide equipment selection and process configuration in magnetite beneficiation.