The aim of this work is the investigation of the simultaneous separation of magnetic (𝜇 r > 80) and conductive (σ ≈ 6 ×107 S/m) particles in a designed magnetic separator. Such a separator consists mainly of a drum on which permanent magnets are arranged and a conveyor belt carrying the material to be purified. The separately driving of the drum and the conveyor belt allows the independent control of the frequency of the generated magnetic field and the displacement speed of the material to be treated. To generate high magnetic field, identical NdFeB permanent magnet bars with residual magnetic flux density B r = 1.2 T are used. To compute the particles trajectories, the magnetic field and the particle dynamic governing equations have been solved using the numerical finite element (FEM) and Runge Kutta (RK4) methods. The computing results have shown that the proposed separator permits the simultaneous separation of magnetic and conductive particles. To check the validity of the numerical results, experiments have been carried out on ferromagnetic powder and conductive particles of different sizes.

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In this work, an identification of the electrical conductivity of material 𝜎 was carried out. This is accomplished by formulating and solving an inverse problem based on the minimization of an objective function using the Particle Swarm Optimization (PSO) method. Such a function represents the difference between the experimentally measured final ejection position and that numerically computed by solving the material magnetic separation problem. For this, the coupled magnetic field and the material dynamic governing equations were numerically solved using the finite element (FE) and Runge–Kutta (RK4) methods. The strong correlation observed between the computed and measured final position of the separated material verifies the accuracy of the proposed identifying approach.