GB1229642A - - Google Patents

Abstract

1,229,642. Producing metals electrolytically. HUMPHREYS & GLASGOW Ltd. Oct.30, 1969 [Nov.11, 1968], No.53417/68. Heading C7B. In electro-refining or electro-winning, the metal to be produced, e.g. Cu, Zn, Sn, Mn, In, Ni, Co, Ag or Au, is electro-deposited in a cell 31 containing an electrolyte 12, e.g. acid CuSO< or ZnSO 4 , on to a cathode consisting of a bed 16 of conducting, preferably metal particles containing the metal to be produced, fluidized by passing the electrolyte therethrough, e.g. recirculated via lines 25, 20, slime filter 28, heat exchanger 9, pump 10 and porous cell base 21, and supplied with current by a stationary conducting member 14 in electrical contact therewith. The anode may be inert, e.g. of C or Pb (alloy), or a rod or slab of impure metal; but preferably is also a bed 15 of metal particles, at rest or fluidized by passing the electrolyte therethrough, e.g. via line 19 and cell base 21, and supplied with current by similar member 13. Particles of either or both beds are preferably spherical having a mean diameter of 20-1000 microns. Both particles of increased and decreased size may be continuously or periodically separated from the respective beds 16, 15, e.g. in a settling tank 24, and replaced by fresh particles, e.g. from poppers 17, 18. Members 13, 14 may be rods or wires forming 1% of the respective total electrode area and be inert or of impure or partially refined metal, e.g. Zn or Al. A porous diaphragm 22 may separate the anode from the cathode. The electrolyte may be aqueous or non-aqueous and contain the metal in solution as a simple or complex salt. In electro-winning Zn, the feed may be ZnO produced by roasting ZnS, and soluble Cd and Fe impurities may be controlled by adding Zn powder and MnO 2 .