| At present,lead and silver alloy anodes are widely used in zinc electrowinning.In the electrolysis process,there are some key technical problems of the anode used to be solved,such as high oxygen evolution potential,low mechanical strength,and lead dissolution.Especially when the concentration of chloride and fluorine in the electrolyte is high,they react with lead alloy to form chlorine and lead fluoride.Th is will greatly reduce the service life of lead alloy anodes.So the development of an energy-saving zinc electrowinning anode material with high activity,corrosion resistance,long life and low cost has been a hot topic for reasearchers.Ti/Sn-Sb-Ru Ox and Ti/Sn-Sb-Ru Ox/α-Pb O2/Ag-dopedβ-Pb O2 Composite Electrodes were prepared by thermal decomposition and electrodeposition.In this article,the peformance of the titanium-base oxide anode was studied from four aspect,including titanium matrix acid etching,the influence of molar ratio of ruthenium to antimony and calcining temperature on the oxide layer,electrodepositing theα-Pb O2 coating by doping potassium dichromate,and electrodepositing theβ-Pb O2 coating by doping silver nitrate.The conclusions ar e as follows:（1）With the increase of hydrochloric acid concentration,the number of pores and pore size on the surface of titanium matrix increase gradually.when the concentration of HCl is at 20%,the Ti/Sn-Sb-Ru Ox electrode has the best electrocatalysis activity and the longest lifetime.Under this condition,the oxygen evolution potential of the electrode is 0.9172V（500A/m2）,the charge transfer resistance Rt is 0.2165Ω·cm2 and the accelerated corrosion lifetime of the electrode is 82h.（2）The results of Ti/Sn-Sb-Ru Ox electrode with different molar ratios and calcining temperatures are shown that the content of ruthenium oxide increases with the increase of ruthenium molar ratio,and the bulk structure of tin-antimony-ruthenium oxide surface becomes larger and the crack becomes smaller and shallower.With the increase of calcination temperature,the cracks on the electrode surface gradually become larger and larger,and the ratio of the amount of active oxides of Ru and Sb increases with the increase of Ru.When the molar ratio of Sn:Sb:Ru is 6:1:2and the calcination temperature is 500°C,the oxygen evolution potential of the prepared titanium-based tin antimony oxide electrode is 0.907V（500A/m2）and the charge transfer resistance Rt is 0.1094Ω·cm2 and the accelerated corrosion life of the electrode is 103h.（3）When potassium dichromate（K2Cr2O7）is added into alkaline lead plating solution,the cathode deposition of lead can be obviously inhibited in the electrodeposition process,so that lead ions in the plating solution can be kept stable,the generation of red Pb 3O4 due to self-decomposition of the solution can be prevented,and the deposition rate ofα-Pb O2 can be improved.Ti/Sn-Sb-Ru Ox/α-Pb O2/β-Pb O2 electrode prepared by adding 2%potassium dichromate has the best performance.The oxygen evolution potential of the electrode was 1.5962V（500A/m2）,and the charge transfer resistance Rt was28.81Ω·cm2.（4）The addition of silver nitrate to the acidic lead plating bath will increase the crystal size ofβ-Pb O2 and decrease the oxygen evolution potential of the Ti/Sn-Sb-Ru Ox/α-Pb O2/β-Pb O2 electrode.When the content of Ag NO3 in bath is at 6g/L,Ti/Sn-Sb-Ru Ox/α-Pb O2/β-Pb O2 electrode prepared has the best performance,the oxygen evolution potential was 1.5016V（500A/m2）,the charge transfer resistance Rt was 4.219Ω·cm2.and the service time of the electrode reaches 249h. |
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