Zinc Electrowinning Of Lead Dioxide With Aluminum Composite Preparation And Electrochemical Properties Of Inert Anode Material

Although Pb-(0.75～1%)alloy anodes are widely used in zinc electrodeposition processess.But the shortages such as high oxygen evolution potential,low conductivity, anodic dissolution pollute the electrolyte,which limits its efficient.Al/Pb/a-PbO2and Al/Pb/α-PbO2/β-PbO2composite inert anodes diffusion doping WC and Co3O4particles,were prepared by single-pulse electrodeposition in alkaline and acid bath,and determine pulse average current density,electrolyte temperature, pulse duty cycle and particle concentration on the electrochemical properties of the prepared composite inert anodes material.In Zn2+50g/L,H2SO4150g/L,35℃solution system (referred to as [Zn2++H2SO4] test solution),and test composite inert anodes material,anode polarization curves and Tafel curves obtained the electrochemical properties of the kinetic parameters,corrosion potential and corrosion current parameters. Al/Pb/α-PbO2/β-PbO2possess better electrocatalytic activity and corrosion resistance compared with Al/Pb/α-PbO2.WC particles can significantly improve the material corrosion resistance in alkaline or acid bath,Co3O4particles have a significant effect for reducing the oxygen evolution potential of the material.The oxygen evolution overpotential of Al/Pb/α-PbO2/β-PbO2-WC-Co3O4composite inert anodes and Pb-1%Ag alloy anode are0.801V and1.171V respectively in the current density of500A·m-2.Compared with Pb-1.0wt%Ag alloy anode,the overpotentials of oxygen evolution of Al/Pb/α-PbO2/β-PbO2-WC-Co3O4composite inert anode are decreased370mV,displaying higher electrocatalytic activity.The corrosion potential and corrosion current of Al/Pb/α-PbO2/β-PbO2-WC-Co3O4composite inert anodes are-0.300V and5.320×10-5A respectively,improved205mV of the corrosion potential and the corrosion current low two orders of magnitude compared with Pb-1%Ag alloy anode.Al/Pb/α-PbO2/β-PbO2-WC-Co3O4composite inert anodes material showing better corrosion resistance.The zinc electrowinning simulation study showed that the cell voltage and power consumption of Al/Pb/α-PbO2/β-PbO2-WC-Co3O4composite inert anode are2.96V and2626.2kW-h/(t-Zn) respectively,which reduced0.24V and263kW·h/(t·Zn) compared with Pb-1.0%Ag alloy anode;The current efficiency of the Al/Pb/α-PbO2/β-PbO2-WC-Co3O4composite inert anode is92.4%,1.6%higher than the Pb-1%Ag alloy anode current efficiency;The life of Al/Pb/α-PbO2/β-PbO2-WC-Co3O4composite inert anodes lower300days than Pb-1.0%Ag alloy anodes.