SELECTIVE RECOVERY OF METALS FROM LEACHING LIQUORS

Metal values are selectively recovered from a liquor by passing the liquor through a cathodic zone, passing an anloyte through an anodic zone, increasing the pH of the liquor in the cathodic zone within the range of 1 to 14 by application of an electric field and selection of appropriate rates of supply of the anolyte and catholyte, the resultant rate of pH increase being such that in the cathodic zone conditions are created for selective recovery of an oxide or hydroxide of the metal at a corresponding pH of deposition. Apparatus for carrying out the process comprises a reactor having separate outlets and inlets for the catholyte liquor and an anolyte; a cathode 2 and an anode 3 coaxially positioned inside the reactor; a cylindrical manifold 8 located in the upper section of the reactor and having electrically insulated from each other (e.g. by spacer 9) an upper chamber 10 and a lower chamber 11 for collection of anodic and cathodic gases respectively; a membrane 4 coaxially secured in the lower section between the cathode and the anode; an electromagnetic coagulator 34, for acceleration of the formation of a solid phase, connected in series with a catholyte recycling pump and the reactor; and a unit for measuring pH of the catholyte.