(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用恒流極化、失重法和抗拉強(qiáng)度測(cè)試研究不同含量Nd的加入對(duì)鋅電積用鉛銀合金陽(yáng)極主要性能(穩(wěn)定陽(yáng)極電位、耐腐蝕性能及力學(xué)性能)的影響，并在此基礎(chǔ)上采用循環(huán)伏安(CV)和計(jì)時(shí)電位(CP)等電化學(xué)手段對(duì)恒流極化條件下Nd的作用機(jī)理進(jìn)行研究。結(jié)果表明：0.03%Nd(質(zhì)量分?jǐn)?shù))加入可以將Pb-Ag合金的抗拉強(qiáng)度提高21.8%；鋅電積條件下，鉛陽(yáng)極表面腐蝕膜主要成分為PbO2及PbSO4，Nd加入可以抑制PbSO4的形成，從而明顯降低陽(yáng)極腐蝕速率；由于Nd能降低析氧過(guò)電位，且對(duì)高阻抗PbSO4的生成具有抑制作用，使得Pb-Ag合金的陽(yáng)極電位亦有一定程度的下降。Nd對(duì)鋅電積陽(yáng)極主要性能均有較大程度的改進(jìn)作用，是很好的鋅電積陽(yáng)極改性劑，具有較好的工業(yè)應(yīng)用前景。
關(guān)鍵字: 鋅電積；釹；鉛稀土合金；耐腐蝕性能；陽(yáng)極電位
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of different Nd additions on the three main properties (anode potential, decay resistance and mechanical property) of lead-silver alloy anode for zinc electrowinning used in galvanizing were investigated by using constant-current polarization, weight-loss method and mechanics performance testing. On this basis, using electrochemical methods, such as cyclic voltammetry (CV) and chronopotentiometry (CP) were used to study the mechanism of action of Nd in galvanostatic polarization conditions. The results show that, 0.03% Nd (mass fraction) addition can enhance the tensile strength of Pb-Ag alloy about 21.8%. The lead anode surface corrosion film mainly composes of PbO2 and PbSO4 in zinc electrowinning conditions, Nd addition can inhibit the formation of PbSO4, consequently reduce the anode corrosion rate obviously. Also there is a certain degree to decline the anode potentials of Pb-Ag alloy due to the Nd reduction of over-potential of oxygen evolution and inhibitory effect of high-impedance PbSO4. So, Nd is a good modifier for zinc electrowinning anode which can improve the three main properties of lead-silver anode.
Key words: zinc electrowinning; neodymium; rare lead-based alloy; resistance properties; anode potential; rare earth
