AQUEOUS ELECTROWINNING OF METALS USING FUEL OXIDIZABLE AT THE ANODE

F24188 An improved process for aqueous electrowinning of metals, using methanol (or another soluble fuel) added to the electrolyte, a catalytically active platinum mesh or platinum-plated titanium anode and periodic current interruption or reversal, in order to maintain a low anodic potential, and hence, a cell voltage and energy consumption lower than in conventional processes. Examples illustrate the electrowinning of zinc and copper from sulfuric acid-sulfate electrolytes, but the process applies to other metals. Also disclosed is the use of an ion-exchange membrane in combination with the above features, in order to decrease the loss of fuel from the anolyte and to minimize the effect at the anode of impurities present in the catholyte.