(1. 江西理工大學(xué) 冶金與化學(xué)工程學(xué)院，贛州 341000； 2. 中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 對比研究鋅電積電解液中氟、氯對Pb-Ag陽極恒流極化(500 A/cm2) 72 h后氧化膜層表面形貌、內(nèi)部結(jié)構(gòu)、物相組成和基底腐蝕的影響。結(jié)果表明：氟、氯抑制PbO2的生長，提高膜層中PbOn、PbO·PbSO4的含量。在含氟溶液中，氧化膜層表面呈鱗片狀，內(nèi)部孔洞、空隙增多，致密度降低；基底出現(xiàn)腐蝕孔洞，隨著氟濃度增大，腐蝕孔洞增多、孔徑增大、腐蝕深度變大。在含氯溶液中，氧化膜層表面呈膠結(jié)狀，致密度與無氯電解液中的相當(dāng)，但緊密層厚度明顯減小；基底出現(xiàn)腐蝕坑，腐蝕深度小于含氟溶液中的。此外，分析了氟、氯對Pb-Ag陽極腐蝕行為的影響機制。氟主要通過降低氧化膜層致密度加劇Pb-Ag陽極的腐蝕，而氯主要通過減小氧化膜層厚度加劇陽極的腐蝕。
關(guān)鍵字: 鋅電積；鉛陽極；氟；氯；氧化膜層；腐蝕
（1. School of Metallurgical and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China; 2. School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:Effects of fluoride and chloride ions on surface morphology, inner structure, phase composition of anodic layer and substrate corrosion of Pb-Ag anode were comparatively investigated after 72 h galvanostatic electrolysis (500 A/cm2) in zinc electrolyte. The results show that both fluoride and chloride ions inhibite the growth of PbO2 in anodic layer, and increase the concentration of PbOn and PbO·PbSO4. In the presence of fluoride ion, anodic layer surface presents scale-like morphology, the inner part of anodic layer shows lower compactness with large numbers of holes and crevices. As fluoride ion concentration ascended, the number and diameter of corrosion holes presented on the metallic substrate increase, and the corrosion depth increases. In the presence of chloride ion, anodic layer surface shows the cement structure, the inner compactness is similar with that in H2SO4 solution without chloride ion, while the thickness of compact layer decreases largely. Metallic substrate shows the corrosion pits, and the corrosion depth is smaller than that in fluoride ion containing electrolyte. Furthermore, the influence mechanism of fluoride and chloride ions on corrosion behavior of Pb-Ag anode is analyzed. Fluoride ion accelerates the corrosion of metallic substrate through decreasing compactness of anodic layer, while chloride ion deteriorates the corrosion of Pb-Ag anode mainly through decreasing the thickness of anodic layer, especially the thickness of inner compact layer.
Key words: zinc electrowinning; lead anode; fluoride; chloride; anodic layer; corrosion
