Preparation And Electrochemical Activity Of Lead-based Modified Anode For Manganese Electrowinnin

The primary method used to produce manganese metal in the world today is electrolysis.Regarding energy use and pollution output in the manganese electrolysis system,the anode material is essential.Currently Pb-based inert anodes continue to dominate the field of electrochemical extraction of manganese with metal.Nonetheless,local governments and related businesses are paying close attention to the issues of environmental contamination and energy consumption brought on by the widespread usage of Pb-based anodes.Based on this,an efficient and clean Pb-0.9%Ag/Ti B₂/-Mn O₂（PTM）hierarchical structure composite lead-based anode was proposed in this thesis.High strength and low resistance combination of corrosion resistant and chemically inert Ti B₂ with conventional lead anodes to shield heavy metal migration through plasma spraying method.Further,theγ-Mn O₂ catalyst was coupled with Ti B₂by electrodeposition to weaken the anodic side reaction.The study aims to solve the problems of easy corrosion,high energy consumption and high anode slag production during the service of conventional anodes.The main innovative findings are as follows:（1）By tuning the Ti B₂ spraying parameters,a charge transfer impedance interface as low as 1.48Ω/cm² was constructed,which reduced the potential oscillation coefficient by 79.32%compared with the conventional lead-silver anode,reflecting the migration shielding effect of Ti B₂ layer on Pb²⁺and O^2-.After the elimination of Pb²⁺interference,theγ-Mn O₂ was able to complete rapid nucleation on Ti B₂ through the Mn³⁺disproportionation pathway.The Ti B₂ surface structure provides anchor points for catalyst coupling to make the film layer dense,while the large specific surface area of pine needle-likeγ-Mn O₂ promotes the reduction of anode potential by 180 m V and overcomes the disorderly growth of anode slime.（2）The lower average valence state of Mn on PTM and 56%of O_v occupation bring the adsorption impedance of the intermediate as low as 1.73Ω/cm².The longer Mn-O（1.9445?）bond shows that this unique layered structure not only protects[Mn O₆]from Pb²⁺,Pb O toxicity,but also optimizes the distribution of active Mn（III）on theγ-Mn O₂surface.DFE demonstrates that the adsorption energy of the active site on PTM is as low as 0.09 e V for*OH.（3）The test for manganese electrowinning was conducted using a 5 L diaphragm double-anode electrolytic cell.By employing PTM with half as much Se O₂（20 mg/L）added,the cathode current efficiency was increased as compared to the usual lead-silver anode from 77.02%to 79.29%and the anode sludge was decreased from 120 g to 6.6g.Continuous polarization for 7 days demonstrated that PTM has superior long-term service stability.