First - Principles Study Of Lead - Based Ternary Alloy Anode For Zinc Electrolytic Deposition

The mainly plate of insoluble anode widely used Lead alloys in modern zinc hydrometallurgy industry. Studies shown that Pb-Sb alloy can be reduced the potential of anode. Pb-Sb alloy with the increase of antimony content caused that the electrode potential reduced and the potential of hydrogen evolution decreased, the percentage of zinc precipitation would reduce. In the application, the lead-antimony alloy decreased the content of antimony and it is used to alleviate the potential of hydrogen evolution decreased. But it caused some defects, such as high electrode potential of anode plate、poor mechanical properties and so on. So the modification of low antimony lead alloy becomes the research direction of some scientific workers.In this article, because the defects of low antimony lead alloy, they were discussed that the modification of electrode potential and mechanical properties on the low antimony lead alloy through adding different contents of rare earth elements (Ce, Pr). We used the first-principles calculation to calculate heat of formation and cohesive energy of lead-based rare earth alloy solid solution. We compared the Fermi level and Elastic constants of Pb-1.86wt% Sb alloy solid solution added RE. By this way we could forecast the electrochemical properties and mechanical properties change of the low antimony lead alloy doped RE. And we prepared electrodes on the basis of calculation. Electrode potential and mechanical properties were tested by alloys’ experimental tests, such as LSV, tensile experiment. And the results contrasted with simulation. So far, the specific results are as follows:(1) When added 1.0wt% Pr, the solid solution model of low antimony lead alloy was unstable, and the other solid solution model could existed stable. That would increase the Fermi level value which added Ce, Pr. From the results of Fermi level, we determined that the best added Ce content is 1.0wt% and the optimum added Pr content is 0.2wt%. And the Fermi level value of the low antimony lead alloy added 1.Owt%Ce was greater than added 0.2wt%Pr.(2) At the same time, the results of G/B value and Poisson’s ratio show that it effectively improved the plasticity of the low antimony lead alloy when the addition of Ce. The change of plasticity of the low antimony lead alloy was not obvious when the addition of Pr.(3) The results of LSV showed that of it could reduce anode potential of Pb-1.86wt% Sb alloy with the adding of Ce and Pr. The trend was consistent with simulation results. The results of CV polarization demonstrated that the addition of rare earth elements Ce, Pr can be accelerated the generation of oxygen. It had the electrocatalytic activity of generated oxygen and reduced the electrode potential. At the same time, it would improve corrosion layer morphology and composition after added Ce, Pr.(4) It can improve uniform elongation when added Ce and Pr. That indicated Ce and Pr could improve the ductility of low antimony-lead alloys, but the effect of ductility when added Ce more significantly than Pr. low antimony-lead alloy of added Ce could solve its problem of poor mechanical properties phenomenon. Elongation experiment and simulation results G/B value exhibited the same law and it reflected the accuracy of the simulation results. Tensile strength increased with the growth content of Ce, Pr. The effect on the tensile strength of low antimony alloy added Pr stronger than Ce.(5) Combined the simulation with experimental results, when added 1.Owt% Ce could effectively improve the problem of low electrode potential for the low antimony lead alloy and avoid the issue of poor mechanical properties.