Precipitation of Antimony and Bismuth from Copper Refinery Electrolyte Using PbO2

Abstract

The invention is suitable for use in metal and nonmetal mining and in general, in any area of operation containing Sb and Bi in solution in an electrolyte based mainly on sulfuric acid. The system consists in contacting solid lead dioxide (PbO 2 ), which can be activated superficially with an oxidizing agent, for example hydrogen peroxide (H 2 O 2 ), to increase its reactivity, with an acid electrolyte that contains Sb and Bi in solution, with the purpose of causing a decrease in the content of soluble Sb and Bi present in the liquid phase, forming insoluble compounds based on Pb—Sb and Pb—Bi. With this invention the presence of Sb and Bi in solution is reduced by at least 70%.

1 . A method for decreasing the content of soluble antimony and bismuth in an electrolyte CHARACTERIZED because it comprises putting in contact lead dioxide with an acid electrolyte that contains antimony and bismuth in solution, yielding insoluble compounds based on Pb—Sb and Pb—Bi. 
     
     
         2 . A method for decreasing the content of soluble antimony and bismuth in an electrolyte according to  claim 1 , CHARACTERIZED because the lead dioxide is in the form of particles. 
     
     
         3 . A method for decreasing the content of soluble antimony and bismuth in an electrolyte according to  claim 1 , CHARACTERIZED because the lead dioxide can or cannot be previously activated superficially with an oxidizing agent, for example hydrogen peroxide (H 2 O 2 ), to improve its extraction capacity. 
     
     
         4 . A method for decreasing the content of soluble antimony and bismuth in an electrolyte according to  claim 1  CHARACTERIZED by the formation of insoluble Pb—Sb based compounds and Pb—Bi compounds. 
     
     
         5 . A method for decreasing the content of soluble antimony and bismuth in an electrolyte according to  claim 1  CHARACTERIZED by allowing the reuse of the particulate system for the precipitation of antimony more than two times. 
     
     
         6 . A method for decreasing the content of soluble antimony and bismuth in an electrolyte according to  claim 1  and  5 , CHARACTERIZED by allowing a reduction of at least 70% of the dissolved antimony and bismuth present in acid electrolytes.