GB224924A - Improvements in or relating to electro-magnetic separation or concentration of minerals - Google Patents

Abstract

224,924. Mordey, W. M. May 17, 1923. Magnetic separators.-In a method of effecting the magnetic separation or concentration of minerals of the type described in Specification 165,822, the material in a finely divided condition is caused to move through an elongated field or fields disposed in the direction of flow of the material and produced by a single phase or multiphase alternating-current system, the responsive material being repelled laterally in opposite directions when the field is produced by a single phase system or laterally in opposite directions, and longitudinally by a field produced by a multiphase system and also in each case in a direction at right angles to the face of the poles. The path of the material may be inclined at such an angle that the material will flow by gravity alone or may be horizontal or nearly so when it is caused to move by shocks or vibrations imparted thereto. The ore &c., usually in the form of pulp, is fed from a hopper d to one end of a relatively long and narrow launder c arranged above the magnet pole a wound with a single coil b traversed by a single phase alternating-current. The launder is made slightly concave or with sides sloping upwards in opposite directions, Fig. 4, the upper surface of the core a being formed to correspond therewith. The core a may be formed of inverted T-shaped stampings or of straight strips of iron as in Fig. 4 or of E-shaped stampings to form three elongated poles. In a modification, the core a which is laminated longitudinally is shaped like a long rack having a succession of vertical poles on its upper side each provided with a multi-phase winding. The strength of the fields may be adjusted by varying the air gap between the poles and the launder or by varying the excitation of the poles. The bottom of the launder may be provided with inclined grooves or riffles extending outwardly and rakes &c. may be suspended in the launder, preferably from fixed supports, to stir up the material and facilitate the separation. The launder may be constituted by the horizontal portion of an endless conveyer. In another modification, Fig. 10. the material from the hopper d provided with a rectangular, curved or circular shaped outlet falls in front of a core a constructed as in Fig. 1 or the modifications referred to above, the responsive material e being repelled in opposite directions and also from the face of the core a, and the inert material f being received in a receptacle i and the material e in a receptacle i<1> which extends partly round the receptacle i.