(1. 中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 難冶有色金屬資源高效利用國(guó)家工程實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 采用恒流極化、計(jì)時(shí)電位、塔菲爾曲線、掃描電子顯微鏡(SEM)和X射線衍射(XRD)對(duì)比研究不同Ag和RE含量Pb-Ag-RE合金陽極的析氧行為和腐蝕行為。結(jié)果表明：減少Ag含量將導(dǎo)致陽極析氧過電位升高，陽極的腐蝕速率增大。RE的加入有利于促進(jìn)高阻抗成分PbSO4、PbO向α-PbO2和β-PbO2轉(zhuǎn)化，進(jìn)而提高陽極的析氧活性，降低陽極電位。此外，RE可以提高氧化膜的致密度，細(xì)化Pb-Ag合金的晶界和枝晶界，減輕合金基底的晶間腐蝕。因此，RE可以有效改善Pb-Ag合金陽極的析氧活性和耐腐蝕性能，微量的RE可以部分取代Pb-Ag陽極中的Ag。
關(guān)鍵字: 鉛基陽極；稀土；電沉積；腐蝕；析氧
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. National Engineering Laboratory for Efficient Utilization of Refractory Nonferrous Metals Resources,
Central South University, Changsha 410083, China）
Abstract:The oxygen evolution and corrosion behaviors of Pb-Ag-RE anodes with different Ag and RE contents were investigated using galvanostatic polarization, chronopotentiometry, Tafel curves, scanning electronic microscopy (SEM) and X-ray diffractometer (XRD). The results show that the reduce of the Ag content leads to the increase of the oxygen evolution overpotential and corrosion rate. The addition of RE benefits to the formation of a dense anodic layer, and then reduces the corrosion of metallic substrate. The RE addition facilitates the transformation of high resistance PbSO4 and PbO to α-PbO2 and β-PbO2, which further helps to enhance oxygen evolution reactivity and reduce anodic overpotential. In addition, RE can improve the compactness of the anodic layer, refine the grain and interdendritic boundaries of Pb-Ag alloy and diminish the interdendritic corrosion of metallic substrate. Consequently, RE can effectively improve the oxygen evolution reactivity and corrosion resistance, trace amounts of RE can partly replace Ag of Pb-Ag anode.
Key words: lead-based anode; rare earth; electrowinning; corrosion; oxygen evolution
