Cyclic Voltammetric Studies of the Behavior of Pb-0.3%Ag-0.06%Ca Rolled Alloy Anode during and after Zinc Electrowinning

Abstract

In this paper, electrochemical behaviour of Pb0.3%Ag0.06%Ca rolled alloy anode during the 6 days galvanostatic electrolysis in acid zinc sulphate electrolyte solution was investigated with Cyclic Voltammetry (CV) techniques. The phase composition of the anodic oxide layers during the electrolysis was observed using X-Ray Diffraction (XRD). The results revealed that with the increasing electrolysis time, the anodic peak (PbPbSO4) is mainly present a rise trend in the first day electrolysis, thereafter, almostly keep a constant value. And the anodic peak (PbPbSO4) gradually moved in the positive direction while the anodic peak (PbSO4β-PbO2, PbOα-PbO2) strongly moved in the negative direction. The cathodic peak (β-PbO2 and α-PbO2PbSO4) and (PbO and PbSO4Pb) mainly present a rise trend and gradually moved in the negative direction. Besides, the corrosion phase of the anodic oxide layers mainly consist of PbSO4, Pb, α-PbO2 and PbS2O3. After electrolysis for 3 days, the major phase of the anodic oxide layers is PbSO4 with a few Pb phase. When the electrolysis reaches the 6th day, the major phase of the anodic oxide layers is also PbSO4 with a few α-PbO2 phase. The preferred growth orientation of PbSO4 is (021) ,(121) and (212) planes.

Electrochemical Behaviors of Pb–0.3%Ag-0.06%Ca Rolled Alloy Anode during and after Zinc Electrowinning - Tafel Investigations

“…This depolarization can be accounted for by the roughness of the anodic surface [3] ; the 5th hour to 2th day when its potential stabilized around 1.40V(MSE); the 2th day to 6th day when its potential decline slowly. This depolarization may be accounted for by the of the anodic surface [6] ; the 6th day to 15th day when its potential stabilized around 1.36V(MSE). Tafel curves and kinetic parameters of oxygen evolution.…”

Homogeneous Microstructure Improving the Mechanical and Electrochemical Properties of Lead Alloys by Stirring Treatment

“…As observed, the pro les contain two main oxidation peaks and two reduction peaks regardless of whether stirring was performed during the preparation process, indicating that the microstructure shows little affect on the main reactions occurring on the substrate. The reaction represented by the oxidation peak a is: Pb + SO 4 2− -2e − =PbSO 4[13]. Potential range [-0.8V, 1.0V] corresponds to PbSO 4 passivation range.…”