GB733282A - Improvements in and relating to methods and apparatus for separating solids having different specific gravities - Google Patents

Abstract

733,282. Washing granular materials. TROMP, K. F. July 31, 1953 [Aug. 6, 1952], No. 21292/53. Class 82 (2). A sink and float process using a suspension which increases in density in downward direction, has horizontal currents to discharge the middlings, the upper part of the suspension and middlings being discharged in a horizontal or upwardly inclined direction and the lower part of the suspension and middlings being discharged in a downward direction. The material to be separated is supplied down a shoot 22 and the floats are removed by the conveyer 8 onto a rinsing-screen 23. The sinks are similarly removed by the conveyer 6 onto screen 26. Medium is supplied by jets 12 onto guide sheets 13 to produce the horizontal currents (suspensions of differing S.G. may be supplied to the jets), the lighter middlings are discharged over a weir 4, the height of which may be adjusted, and the heavier middlings are discharged down a vertical conduit 15 both to a screen 24. The heavier suspension (from conduit 15) drains into a boot 27 and is returned to the tank by a pump 28 and the lighter suspension (from weir 4) drains into a boot 29 and is returned to the jets 12 by a pump 30. Overflow from boot 27, in which the suspension settles, runs into boot 29 thus keeping up the specific gravity in boot 27. Air may be injected at 31 to mix the suspension lying above the conduit 15. The weir 4 can be varied in height periodically by a drive from the top roller of the conveyer 8.