Certain peculiarities of the influence of antimony on electrolysis parameters of zinc

The influence of antimony ions (Sb3+) in a concentration range of 0.001–0.200 mg/L on the current yield of zinc during the electrolysis of sulfate solutions is investigated. It is established that antimony, in contrast with germanium and tin, promotes an increase in the current yield of zinc under definite conditions. This is caused by the fact that a zinc alloy with antimony, which possesses a potential more positive than zinc, is deposited on separate cathode segments, which is why the discharge of zinc ions proceeds in the depolarization mode with a higher current yield. A decrease in the current yield of zinc with a fraction of antimony higher than 0.2 mg/L is associated with the prevalent effect of galvanic pairs of antimony with zinc over the electrolysis with the depolarization. It is established that antimony enhances the negative effect of cobalt on the current yield of zinc due to the formation of cobalt alloy with antimony, for which the isolation overvoltage of hydrogen is lower than for zinc.