Abstract Copper is the major impurity dissolved in silver electrorefining which potentially accumulates in the electrolyte during the process and co-deposits onto the cathode surface, decreasing the product quality. The study investigated the dissolution kinetics of copper in silver electrorefining as a function of wt%Cu in the industrial electrolyte ranges of 40–100 g/dm3 [Ag+], 5–15 g/dm3 [HNO3] and 20–60 g/dm3 [Cu2+] at 25–45 °C. The results showed that Cu dissolved at a higher rate in comparison to silver and that the two kinetic models developed have good accuracy and validity. From the models, optimal electrolyte circulation parameters were simulated to avoid [Cu2+] accumulation in the electrolyte. As a conclusion, processing 1% Cu anodes at the critical [Cu2+]/[Ag+] ratio of 0.8 in the electrolyte requires an inlet of [Ag+] of 2.3–3.3 and tolerates [Cu2+] of 0.14–0.47 times that of the [Ag+] and [Cu2+] in the bulk electrolyte, respectively. Furthermore, electrolyte with higher [Ag+] provides the benefit of reduced electrolyte circulation flowrate and increased tolerance of wt%Cu in the silver anodes.

中文翻译：

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基于银电解精炼铜溶解动力学模型的最佳电解液循环设计

摘要 铜是银电解精炼过程中溶解的主要杂质，在电解过程中可能会在电解液中积累并共沉积到阴极表面，从而降低产品质量。该研究调查了铜在银电解精炼中的溶解动力学与重量百分比 Cu 在 40–100 g/dm3 [Ag+]、5–15 g/dm3 [HNO3] 和 20–60 g/dm3 工业电解液范围内的函数关系[Cu2+] 在 25–45 °C。结果表明，与银相比，Cu 以更高的速度溶解，并且开发的两种动力学模型具有良好的准确性和有效性。根据模型，模拟了最佳电解液循环参数，以避免电解液中的 [Cu2+] 积累。总之，在电解液中以 0.8 的临界 [Cu2+]/[Ag+] 比处理 1% 铜阳极需要 2.3-3 的 [Ag+] 入口。3 并且耐受 [Cu2+] 分别是本体电解质中 [Ag+] 和 [Cu2+] 的 0.14-0.47 倍。此外，具有较高 [Ag+] 的电解液具有降低电解液循环流速和提高银阳极中 Cu 重量百分比耐受性的好处。