MODELLING OF MAGNETIC CARRIER SEPARATION PROCESS USING COMPUTATIONAL FLUID DYNAMICS

摘要

The principle of operation of magnetic separation units rely on the interaction between magnetic,hydrodynamic, gravitational, and inter-particle forces. We incorporate these forces in a mathematicalmodel using a computational fluid dynamic framework to study separation behaviour of iron particlesfrom a banded haematite quartzite (BHQ) ore using a wet high intensity magnetic separator. Here thesource of a constant magnetic field is an electromagnet. The grooved plates, made of ferromagneticmaterial, placed between the poles of the electromagnet, serve as a trap for particles. The mainobjective is to optimize the flow rate as well as the intensity of the magnetic field so that magneticparticles are trapped on the plates while the non-magnetic particles flow out. A three-dimensionalEulerian-Eulerian model has been developed to predict the flow profile as well as the concentrationprofile of the iron particles between two parallel plates. The Navier-Stokes equation is used to predictthe flow profile for the liquid phase. The solid phase consists of two species, ie magnetic and nonmagneticparticles. The model equations have been solved using the finite volume solver available incommercial CFD software, Fluent, to estimate the volume fraction of magnetic particles captured bythe plates. Simulation results show that most of the magnetic particles are trapped on the magneticplate which has also been observed experimentally.