Numerical Simulation of Mineral Separation Method Using an Isodynamic Magnetic Field

An improved method for separating magnetic minerals based on an isodynamic magnetic field is proposed in this work. The magnetic field distribution generated by the system was first analyzed through numerical simulations performed with finite element electromagnetic simulation software, and the simulation accuracy was subsequently validated against experimental data. Through system modeling and parameter sensitivity analysis, the regulatory mechanisms of various parameters of the field properties were thoroughly investigated. Numerical results show that a constant magnetic force field forms in the separation zone at a 25° arc center angle of the curved pole head, while poor field uniformity occurs at 20° or 30°. A stable constant magnetic force field can be generated in the separation zone when the large arc radius of the curved pole head is 300 mm, 600 mm or 1200 mm, or when permanent magnet materials including N30–N45-grade neodymium iron boron (NdFeB) and ferrite are adopted. The large arc radius of the curved pole head, as well as the type and grade of the permanent magnet, only affect the magnitude of the magnetic force in the separation zone, with no significant correlation with the uniformity of the constant magnetic force field. A constant magnetic force field is generated when the thickness of the side patch magnet on the curved pole head is 40–70 mm and the magnetic system working air gap is 50–60 mm; the magnetic force field will lose uniformity once the parameters deviate from the above ranges.