Abstract Cyanide leach solutions produced from gold/silver ores can be contaminated with zinc due to the gold/silver cementation in Merrill-Crowe process and/or the dissolution of zinc minerals present in the ore. Zinc levels in cyanide solutions should be controlled to avoid potential problems in leaching and downstream processes associated with the accumulation of zinc. In this study, the application of a novel method was demonstrated for the precipitation of zinc from synthetic/real cyanide solutions using Trimercapto-s-triazine (TMT), a non-toxic organic reagent. Experimental studies have shown that precipitation of zinc with TMT is a fast process occurring in a short period of time i.e., ≤15 min. Increasing the concentration of TMT (33–90 mM) and pH (10–12.5) was found to improve the precipitation of zinc, which was unaffected by increasing the temperature (20–60 °C). Response surface methodology was adopted for detailed investigation of the effect of [TMT]/[Zn] ratio (2.70–16.25), [CN−]/[Zn] ratio (3.00–8.00) and initial concentration of Zn (50–950 mg/L) on the precipitation of zinc. High recoveries (≤95.4%) were obtained under suitable conditions. Precipitation tests were also performed using synthetic multi-metal and real leach solutions. The complete recovery/dissolution of zinc from the precipitates was also demonstrated using different acids (HCl and H2SO4). The findings have shown that TMT can be effectively used as an environmentally friendly reagent for removal of zinc from cyanide leach solutions.

中文翻译：

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使用三巯基-s-三嗪 (TMT) 从氰化物浸出溶液中沉淀锌

摘要 由于 Merrill-Crowe 工艺中金/银的胶结作用和/或矿石中存在的锌矿物的溶解，金/银矿石生产的氰化物浸出溶液可能会被锌污染。应控制氰化物溶液中的锌含量，以避免在浸出和下游工艺中与锌的积累相关的潜在问题。在这项研究中，展示了一种使用无毒有机试剂三巯基-s-三嗪 (TMT) 从合成/真实氰化物溶液中沉淀锌的新方法的应用。实验研究表明，锌与 TMT 的沉淀是在短时间内发生的快速过程，即≤15 分钟。发现增加 TMT 的浓度 (33-90 mM) 和 pH (10-12.5) 可以改善锌的沉淀，这不受温度升高（20-60°C）的影响。采用响应面方法详细研究 [TMT]/[Zn] 比 (2.70–16.25)、[CN-]/[Zn] 比 (3.00–8.00) 和 Zn 初始浓度 (50–950 mg) 的影响/L) 对锌的沉淀。在合适的条件下获得了高回收率 (≤95.4%)。还使用合成多金属和真实浸出溶液进行了沉淀测试。还使用不同的酸（HCl 和 H2SO4）证明了从沉淀物中完全回收/溶解锌。研究结果表明，TMT 可以有效地用作从氰化物浸出溶液中去除锌的环保试剂。[CN-]/[Zn] 比 (3.00–8.00) 和锌的初始浓度 (50–950 mg/L) 对锌沉淀的影响。在合适的条件下获得了高回收率 (≤95.4%)。还使用合成多金属和真实浸出溶液进行了沉淀测试。还使用不同的酸（HCl 和 H2SO4）证明了从沉淀物中完全回收/溶解锌。研究结果表明，TMT 可以有效地用作从氰化物浸出溶液中去除锌的环保试剂。[CN-]/[Zn] 比 (3.00–8.00) 和锌的初始浓度 (50–950 mg/L) 对锌沉淀的影响。在合适的条件下获得了高回收率 (≤95.4%)。还使用合成多金属和真实浸出溶液进行了沉淀测试。还使用不同的酸（HCl 和 H2SO4）证明了从沉淀物中完全回收/溶解锌。研究结果表明，TMT 可以有效地用作从氰化物浸出溶液中去除锌的环保试剂。还使用不同的酸（HCl 和 H2SO4）证明了从沉淀物中完全回收/溶解锌。研究结果表明，TMT 可以有效地用作从氰化物浸出溶液中去除锌的环保试剂。还使用不同的酸（HCl 和 H2SO4）证明了从沉淀物中完全回收/溶解锌。研究结果表明，TMT 可以有效地用作从氰化物浸出溶液中去除锌的环保试剂。