Electrolytic treatment of plating wastes
AssigneeKennecott Copper Corporation
InventorsCharles Portal, Glenn M. Cook
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Abstract
The known method of removing heavy metal and cyanide ions from plating waste solutions wherein the solution is passed through flow-through, high surface area electrodes to precipitate heavy metal ions and to oxidize cyanide is improved through the use of a novel stationary bed dual electrode capable of reducing heavy metal and cyanide ion concentration. The process promotes economical electrolytic purification because it can be accomplished at relatively high current efficiencies. The metals removed from the solutions are recovered in a concentrated form suitable for purification.
Claims11
In the method of reducing the concentration of a heavy metal in an aqueous solution of plating wastes wherein the metal is precipitated electrolytically as it passes through a high surface area flow-through electrode, the improvement comprising:
- A. placing a stationary bed electrode in a tank, said electrode comprising
- mating electrically nonconductive support frames;
- a pair of perforated, electrically conductive, flow distributor plates attached to each frame and facing each other to form a cavity;
- a pair of porous, bed supports adapted for attachment to said frame on the side of each distributor plate opposite the cavity creating a pair of basket-like compartments;
- a porous, conductive bed in each of said compartments;
- and
- a first quickly releasing means for holding said mated frame together;
- B. feeding a solution of plating wastes to the cavity and through the distributor plates and beds while passing a current through the bed to plate a heavy metal therein and rejecting a solution reduced in heavy metal concentration from the tank;
- C. releasing said first quickly releasing means to expose the bed;
- D. removing the bed containing plated heavy metal from said compartment;
- E. placing a fresh porous conductive bed in said compartment;
- and
- F. repeating steps A through E.
Dependencies are inferred from the claim text.