GB465126A - Improvements in or relating to the separation of solid materials of different specific gravities - Google Patents

Abstract

465,126. Separating solid materials. VOOYS, G. J. DE. Oct. 31, 1935, No. 30102. Convention date, Oct. 31, 1934. [Classes 82 (ii) and 117] The sink material from a sink and float separation in a fluid separating medium of higher density than water is separated into fractions of different specific gravities by subjecting it to current treatment in a stream of the same separating medium which is in communication with but operates independently of the main body of the medium used in the initial sink and float separation. A plurality of streams, in series or in parallel, may be employed so that the sink material from the initial separation is separated into more than two fractions. The separating medium may be a solution, a suspension of solids in liquid, e.g. sand in water or a sludge of clay, barytes, and water, or it may be a suspension of solids in gas, e.g. sand in air. The streams used in the current treatment preferably move in closed circuits. The apparatus shown comprises a vessel A in which the initial sink and float treatment is carried out and a delivery vessel D for the heaviest product. These vessels contain separating medium in a substantially static condition, though small currents, preferably controlled by means of adjustable overflows, may exist due to the supply of medium to replace that removed with the separated fractions or due to the recirculation of small quantities of overflowing medium. The lightest material floats in the vessel A and is drawn off by any known means. Between the vessels A and D is provided a vessel comprising tubes B and C, to which the sink material from A passes through a connection E. An upward current of medium is produced in one of the tubes, e.g. the tube B, by any suitable means, for example a screw propeller e, a pump, a turbine, or compressed air. The lighter part of the sink material is carried up the tube B and removed by any suitable means, the liquid passing into the tube C through the connection F, and the heavier fraction sinks into the well H of the delivery vessel D. A plurality of closed circuit separating vessels may be arranged in series or in parallel between the vessels A and D, the currents in the several vessels having uniform velocities of different magnitudes. The upward-current separators may, if desired, be replaced by separating vessels utilizing horizontal currents.