DEVELOPMENT OF CONTINUOUS ZINC ELECTROWINNING

电积法是生产锌的最重要的方法。该工艺使用低电流密度（57mA/cm^2）和高电池电压（3.6V），因为阳极极化和电解质中的欧姆降很大。阳极由铅银合金制成，通常含有0.5%的银。阴极是铝板。我们将阳极替换为气体扩散电极（400cm^2），氢气被馈送到气体扩散电极，阴极被馈送到1mphi Al旋转盘。阳极和阴极之间的间隙为4mm。用锌粉对含60g/1 Zn和180g/1 H_2SO_4的电解液进行提纯。新型连续锌电积系统生产带状锌。电池电压分别为0.35A/cm^2时的1.81V和0.7A/cm^2时的2.67V。电流效率在0.45A/cm^2时为90%，在0.7A/cm^2时为86.5%。锌纯度为99.999%。系统能耗为1400kWh，每吨锌380m^3 H_2气。这个制度很容易实施。

Electrowinning is the most important method by which zinc is produced. This process uses a low current density (57mA/cm^2) and high cell voltage (3.6V), because the anode polarization and the ohmic drop in the electrolyte are large. The anode is made from a lead-silver alloy which usually contains 0.5% Ag. The cathode is Al plate.We replaced the anode to a gas diffusion electrode (400cm^2) and hydrogen is fed to the gas diffusion electrode and the cathode to 1mphi Al rotating disk. The gap between anode and cathode is 4mm. The electrolyte solution, containing 60g/1 Zn and 180g/1 H_2SO_4 was purified by Zn powder. The new type continuous zinc electrowinning system produced a belted zinc. The cell voltage is 1.81V at 0.35A/cm^2 and 2.67V at 0.7A/cm^2 respectively. The current efficiency 90% at 0.45A/cm^2 and 86.5% at 0.7A/cm^2 respectively. The zinc purity is 99.999%. The energy usage of the system is 1400kWh and 380m^3 H_2 gas per ton of zinc. This system will be easily put into practice.