锌电积用Pb-Ag-Sb-Ca四元合金阳极的电化学性能研究

Electrochemical Behaviors of Pb-Ag-Sb-Ca Quaternary Alloy Anode for Zinc Electrowinning

实验通过恒电流极化(24 h)、阳极极化曲线等技术在酸性硫酸锌溶液中测试了Pb-0.3%Ag-0.6%Sb-0.06%Ca四元合金阳极的电化学性能,并分析了其析氧动力学参数.结果表明:相对于传统的Pb-0.3%Ag-0.06%Ca阳极,Pb-0.3%Ag-0.6%Sb-0.06%Ca四元合金阳极析氧过电位低27 mV(500 A/m2);电极表观交换电流密度增高将近一倍.元素Sb明显的提高了Pb-0.3%Ag-0.06%Ca阳极的电催化活性,有利于析氧反应的发生和槽电压的降低,节约电能消耗,是很好的锌电积阳极改性剂,具有较好的工业应用前景.

In this paper, oxygen evolution kinetics and electrochemical behaviour of Pb -0.3% Ag - 0.6% Sb - 0.06% Ca quaternary alloy anode during the 24 hours galvanostatic electrolysis in acid zinc sulphate electrolyte so- lution is investigated with anodic polarization curves. Compared with industrial Pb-0.3% Ag-0.06% Ca anodes, the overpotential of oxygen evolution of Pb -0.3%Ag- 0.6% Sb -0.06% Ca is 27 mV lower at 500 A/m2, and the electrode surface exchange current density is about two times higher in value than the ones for Pb -0.3% Ag - 0.06% Ca anodes. For Pb - 0.3% Ag - 0.06% Ca anode, Sb addition obviously improves the electrocatalytic activi- ty, benefits oxygen evolution reaction as well as reduces cell voltage and power consumption. Therefore, Sb is a good modifier for zinc electrowinning anode with a ~ood industry nnnli,-m;