(1. 江西理工大學 冶金工程學院, 贛州 341000；
2. 江西自立環(huán)保科技有限公司 企業(yè)技術中心, 撫州 344113)
摘 要: 傳統(tǒng)錫電解精煉采用H2SO4-SnSO4-甲酚磺酸電解液體系，然而，甲酚磺酸氣味重、有毒有害，亟待尋找新型綠色環(huán)保添加劑替代甲酚磺酸。通過線性掃描、Tafel測試、滴定分析和掃描電子顯微鏡對比研究了甲酚磺酸和沒食子酸對電解液穩(wěn)定性和Sn(II)陰極沉積行為的影響。結果表明：沒食子酸的還原性強于甲酚磺酸的還原性，顯著抑制析氫副反應。添加沒食子酸可以使電解液酸度維持穩(wěn)定，而且Sn(II)濃度和Sn(II)占總錫(S(T))比例保持在較高水平。相較于甲酚磺酸，沒食子酸更有利于提高電解液穩(wěn)定性。甲酚磺酸顯著阻滯Sn(II)的沉積，增強陰極極化，陰極錫致密平整，甲酚磺酸平整效果好。然而，沒食子酸對Sn(II)沉積動力學影響小，其陰極錫平整度、致密度低于甲酚磺酸體系的，添加高濃度沒食子酸甚至會導致錫枝晶產生。木質素磺酸鈉作為一種整平劑，與沒食子酸復合添加可以顯著改善陰極錫的平整度和致密度，兩者組成的復合添加劑有望取代甲酚磺酸成為新型錫電解精煉電解液綠色添加劑。
關鍵字: 錫電解精煉；甲酚磺酸；沒食子酸；木質素磺酸鈉；穩(wěn)定性；形貌
（1. School of Metallurgical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China;
2. Technology Center, Jiangxi Self-Independence Environment Protection Science and Technology Ltd., Fuzhou 344133, China）
Abstract:Traditional tin electrorefining proceeds in electrolyte containing H2SO4, SnSO4 and cresol sulfonic acid (CSA). It is urgent to search novel environmental electrolyte additive to replace CSA due to its stench and toxicity. Influences of CSA and gallic acid (GA) on electrolyte stability and Sn(II) electrodeposit behavior were comparatively investigated through linear scanning voltammetry, Tafel test, titration analysis and SEM. The results show that GA presents stronger reducibility than that CSA does, and remarkably inhibits hydrogen evolution side reaction. Addition of GA stabilizes electrolyte acidity, and enhances Sn(II) concentration and Sn(II)/Sn(T) ratio. Compared with CSA, GA is more suitable to enhance electrolyte stability. Addition of CSA apparently inhibits Sn(II) electrodeposition and increases cathodic polarization. Therefore, CSA presents excellent flattening effect. However, GA shows smaller influence on Sn(II) electrodeposition dynamic, and decreases the flatness and compactness of cathodic tin. Moreover, addition of GA in high concentration results in the appearance of tin dendrites. Sodium ligninsulfonate (SL), as a leveling agent, is selected and combined with GA. Composite additive of SL and GA is demonstrated to improve compactness and flatness of cathodic tin. Consequently, SL-GA composite additive is a potential alternative to CAS. It could be a novel environmental-friendly additive for tin electrorefining.
Key words: tin electrorefining; cresol sulfonic acid; gallic acid; sodium ligninsulfonate; stability; morphology
