Simulation of magnetic separation process in wet low intensity magnetic separator using DPM-CFD Method

Low Intensity Magnetic Separators (LIMS) are widely used in research and industry. The design of this separator is based on drum rotation inside a tank media, so that a permanent magnets placing inside the drum as an angle form, produces a magnetic field. In this study, the behavior of magnetic and none-magnetic particles of a pulp, flowing through a magnetic field in the wet LIMS, was simulated and validated by experimental results. The magnetic field variables were calculated in an FEM based simulator (COMSOL Multiphysics); while particles’ tracking was done applying CFD numerical method, enhanced by discrete phase model (DPM). The difference between the results of the simulation and the magnetic separation experimental test (recovery of magnetic particles in the concentrate product) was ۱۶.۴%. In order to quantify the results of the simulation, magnetic separation simulation was performed by changing two variables affecting the magnetic separation process (variables of particle size of the input pulp feed particles and solid percentage of input pulp) and corresponding experiments. Comparison of laboratory and simulation results showed that the trend of simulation results is consistent with laboratory results of the weight recovery (in both variables under study), so that the maximum simulation error is related to the size of ۱۲۵ microns (۱۶.۵ %) and the lowest simulation error was in ۱۸۰ microns (۱۱.۴ %). Also, the lowest simulation error in the weight recovery prediction was related to the pulp feed solid percentage of ۱۵% (equivalent to ۱۴%) and the highest simulation error was in ۳۰% pulp feed solid percentage (۱۶.۹ %). This proposes that FEM-DPM-CFD coupling model, can be applied for simulation, optimization, design and construct

کلیدواژه ها:

Magnetic separation ، wet LIMS ، finite element method (FEM) ، computational fluid dynamics (CFD) ، discrete phase model (DP)M