GB1317736A - Method of and apparatus for or for use in the separation of particles - Google Patents

Abstract

1317736 Magnetic separators VANDERBILT UNIVERSITY 5 Aug 1970 [5 Aug 1969] 37710/70 Heading B2J Particles of different electrical conductivity are separated by moving the particles through successive regions of increasing, substantially constant and decreasing magnetic field strength whereby the velocity, orientation or point of exit from the magnetic field is varied dependent on the electrical conductivity. In the case of variations in velocity and orientation, separation is completed by subsequently applying a separating force or using a mechanical separator. In a first embodiment (Fig. 1) particles 15 are dropped between vertically staggered poles 13, 14 of a permanent or electromagnet 11, 12. Particles will fall unaffected (21) or be deflected (22 and 23) according to their conductivities and densities. In a second embodiment (Fig. 2, not shown) in. which the pole pieces are level, a subsequent separating force is applied by a fluid jet to separate the particles according to their different velocities. In a modification of this embodiment the particles are projected horizontally between vertically aligned poles and the subsequent separating force is provided by gravity. In a further embodiment (Fig. 4) elongated and preferably flat particles are dropped through an unbalanced magnetic field provided by a permanent or electro-magnet with only one pole piece whereby the particles are rotated according to their conductivity and only unaffected (non-conducting) particles will pass through an aperture between deflector plate 88. In modifications, particles may be rolled down an inclined plane through a magnetic field, or may be wound by inclined troughs or endless conveyor belts. Super-conducting electromagnets may be used. The process may be preceded by a conventional magnetic separator.