Method for producing sheet-form electrolytic copper from halide solution

Abstract

In a method for producing dense sheet-form electrolytic copper by electrowinning, the electrolyte contains a polyethylene glycol additive as a smoothening agent. In the prior art method, stirring is necessary. In an electrowinning method without stirring, the current concentrates on the edge portion of cathode 2 . This current concentration is mitigated by means of conducting the electrolyzing current through a window 6 b of a shielding plate 6 located in the vicinity of a cathode 2.

1 . A method for producing dense sheet-form electrolytic copper, wherein the electrowinning is carried out in the halide electrolyte being fed into an electrolytic cell, which electrolyte contains a polyethylene glycol additive as a smoothening agent, characterized in that the electrolyzing current is conducted through a window of a shielding plate located in the vicinity of a cathode, thereby mitigating current concentration on the edge of the cathode by the plate portion defining the window and having substantially the same dimension as the edge region of the cathode. 
     
     
         2 . A method for producing dense sheet-form electrolytic copper according to  claim 1 , wherein the copper-halide electrolyte contains not less than 3 mol/L of alkali metal chloride, alkali metal bromide or a mixture of the alkali metal chloride and bromide as a bearing salt, and also dissolves copper in the form of chloride or bromide. 
     
     
         3 . A method for producing dense sheet-form electrolytic copper according to  claim 1  or  2 , wherein the concentration of the polyethylene glycol additive is from 20 mg/L to 40 mg/L, and further the current density is not more than 125 A/m 2 .