Electromagnetic eddy current materials separator apparatus and method

Abstract

An electromagnetic eddy current materials separator is disclosed herein for use in separating particles of greater electrical conductivity from particles of lesser electrical conductivity and, in particular, for separating non-ferrous metallics from ferrous metallics and non-metallics. An electromagnet is energized by current pulses, pulsing the magnet several times while each particle is in the field of influence of the magnet causing eddy currents to be developed in the particles and resulting in a repulsive force being developed between the magnet and the material, causing the material to be repelled from the magnet, the repulsive force varying directly with the electrical conductivity of the material and the momentum imparted to such particles varying directly with the number of current pulses occurring while each particle is in the field of influence of the magnet. Current is supplied to the magnet only when conductive materials are detected to be within the region of influence of the magnetic field of the magnet, to reduce the duty cycle of activation of the magnet and reduce the power requirement of the apparatus.