Electrolytic Reduction of Marine-bronze Artifacts

出水青铜器电解还原脱盐修复

type:case-study · level:advanced · material:bronze · variant:chloride · scale:sculpture · equipment:power-supply · equipment:hand-tools · stage:cleanup · stage:sealing

标签：海洋出水, 电解还原, 脱盐, 氯离子, 博物馆修复

海底出水青铜器内部充满氯化物，直接暴露会爆发碱式氯化铜活性锈。实验室常用碱性电解还原：2% NaOH 或 5% 甲酸钠电解液、不锈钢阳极、电流密度 0.1–0.5 A/dm²，文物接阴极，通电 4–8 周使 Cl⁻ 迁出；随后去离子水煮沸置换、乙醇脱水、BTA 缓蚀并封蜡。沉船铜权、铜炮类器物经此处理后氯离子含量可降至 20 ppm 以下，十年随访未见活性锈复发，是水下考古金属文物的标准路线。

Marine-bronze artifacts are saturated with chlorides and erupt in basic copper chloride corrosion once exposed. Labs apply alkaline electrolytic reduction: 2% NaOH or 5% sodium formate, stainless anodes, 0.1–0.5 A/dm², artifact as cathode, running 4–8 weeks to draw out Cl⁻; then boiling DI-water rinses, ethanol dehydration, BTA inhibition and wax sealing. Desalinated weights and guns reach <20 ppm chloride with no active corrosion over a decade of follow-up. ---