GB984068A - Heavy-medium separation of minerals - Google Patents

Abstract

984,068. Sink-float apparatus. UNITED STATES STEEL CORPORATION. Dec. 30, 1963 [Dec. 31, 1962], No. 51209/63. Heading B2H. A heavy-medium process for separating coal or other mineral materials into three fractions comprises introducing at one end of a vessel the material to be separated and a liquid medium of specific gravity such that the low-density particles float thereon and are discharged over a weir 15 and the middlings and high density particles sink, means, such as a grid 13, being provided to separate the small high-density particles from the large middlings according to size as they sink in the same region so that the large and small high density particles may be recovered as a first sink fratcion and the large and small middlings as a second sink fraction. The liquid medium is introduced through a manifold 12 and discharged over the weir 15. The large high-density particles sink before reaching the grid 13 and collect, together with the small high-density particles falling through the grid, at the bottom of the vessel and to one side of a partition 14 ; the large middlings pass down the surface of the sloping grid to the other side of the partition where they collect together with the small middlings. The length of grid and position of the partition 14 together with a further portion 37 can be adjusted to give sharp separation. The partitions 14, 37 are mounted on scrapers, 35, 34 which are arranged to reciprocate up and down sloping walls 17, 24 by a piston 27 operating in a cylinder 26 for dragging the sinks up in stages and discharging them over weirs 38, 39 at the top of the vessel.