Metal electrowinning anode and electrowinning method

Abstract

The present invention has a problem aiming to provide an electrowinning system capable of suppressing accumulation of a side reaction product on an anode and a rise of an electrolysis voltage caused thereby, and also to provide an electrowinning method using the system. To solve this problem, the electrowinning system of the present invention applies predetermined electrolysis current between an anode and a cathode placed in an electrolyte, thereby depositing a desired metal on the cathode, in which the electrolyte is a sulfuric acid-based or chloride-based solution containing ions of the metal, and the anode has a catalytic layer, containing amorphous iridium oxide or amorphous ruthenium oxide, formed on a conductive substrate.

1 - 7 . (canceled) 
     
     
         8 . An electrowinning anode for use in electrowinning of any one of nickel, zinc or cobalt, comprising a conductive substrate and a catalytic layer formed on the conductive substrate, wherein the catalytic layer contains amorphous iridium oxide, so that a side reaction on the anode is suppressible. 
     
     
         9 . The electrowinning anode according to  claim 8 , being used in nickel electrowinning. 
     
     
         10 . The electrowinning anode according to  claim 8 , wherein the catalytic layer contains amorphous iridium oxide and amorphous tantalum oxide. 
     
     
         11 . An electrowinning anode for use in electrowinning of any one of nickel, zinc or cobalt, comprising a conductive substrate and a catalytic layer formed on the conductive substrate, wherein the catalytic layer contains amorphous ruthenium oxide, so that a side reaction on the anode is suppressible. 
     
     
         12 . The electrowinning anode according to  claim 11 , being used in nickel electrowinning. 
     
     
         13 . The electrowinning anode according to  claim 11 , wherein the amorphous ruthenium oxide in the catalytic layer is a composite oxide of amorphous ruthenium oxide and amorphous titanium oxide. 
     
     
         14 . The electrowinning anode according to  claim 8 , wherein the side reaction is a reaction in which a manganese compound is generated. 
     
     
         15 . The electrowinning anode according to  claim 8 , further comprising an intermediate layer made of tantalum or a tantalum alloy, wherein the intermediate layer is formed between the conductive substrate and the catalytic layer. 
     
     
         16 . An electrowinning method using an anode which is an electrowinning anode of  claim 8 . 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . The electrowinning anode according to  claim 11 , wherein the side reaction is a reaction in which a manganese compound is generated. 
     
     
         20 . The electrowinning anode according to  claim 11 , further comprising an intermediate layer made of tantalum or a tantalum alloy, wherein the intermediate layer is formed between the conductive substrate and the catalytic layer. 
     
     
         21 . An electrowinning method using an anode which is an electrowinning anode of  claim 11 .