The cyanidation of gold. 1. Mixed potential and dissolution studies

IF 4.8 2区材料科学 Q1 METALLURGY & METALLURGICAL ENGINEERING

Hydrometallurgy Pub Date : 2025-09-27 DOI:10.1016/j.hydromet.2025.106579

M. Nicol

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Abstract

Despite the fact that the cyanidation process for the recovery of gold was patented almost 140 years ago, understanding of the dissolution of gold has proved to be particularly elusive. While it is widely accepted to be a typical electrochemically-based corrosion process, details of the published kinetics of the anodic and cathodic reactions have been found to be very variable with little agreement between many studies, predominantly of the anodic reaction.

In this series of three papers, an attempt has been made to shed some light on the electrochemistry of gold in cyanide solutions. Unlike many previous studies, the use of gold‑silver alloys and an electrode fabricated using gold from an actual plant have been used in addition to pure gold. Solutions from two gold plants have also been compared to pure solutions.

The first of these papers summarizes and compares the literature on the anodic characteristics of gold dissolution in cyanide solutions. The use of the mixed-potential model to describe the kinetics of gold dissolution and the important measurement of mixed potentials under typical cyanidation conditions are described in detail with an emphasis on the possible passivation of gold and the effect of the metal and solution composition on the passivation process.

A number of small scale dissolution experiments using various gold materials and solutions has been undertaken in conjunction with mixed potential and anodic voltammetric measurements. This study has shown that electrochemical studies using pure gold electrodes in pure solutions cannot be used to predict the reactivity of gold under actual plant conditions.

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氰化金1. 混合电位和溶出度研究

尽管回收黄金的氰化工艺在140年前就获得了专利，但事实证明，对黄金溶解的理解尤其难以捉摸。虽然人们普遍认为这是一种典型的电化学腐蚀过程，但已发表的阳极和阴极反应动力学的细节却变化很大，许多研究之间几乎没有一致性，主要是阳极反应。在这一系列的三篇论文中，试图阐明金在氰化物溶液中的电化学。与以前的许多研究不同，除了使用纯金之外，还使用了金-银合金和用来自实际植物的金制成的电极。两种金植物的溶液也与纯溶液进行了比较。本文首先对有关金在氰化物溶液中溶解的阳极特性的文献进行了总结和比较。详细介绍了在典型氰化条件下使用混合电位模型描述金溶解动力学和混合电位的重要测量，重点介绍了金可能的钝化以及金属和溶液组成对钝化过程的影响。在混合电位和阳极伏安测量的基础上，利用各种金材料和溶液进行了一系列小规模的溶解实验。这项研究表明，在纯溶液中使用纯金电极的电化学研究不能用于预测实际工厂条件下金的反应性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Hydrometallurgy 工程技术-冶金工程

CiteScore

9.50

自引率

6.40%

发文量

144

审稿时长

3.4 months

期刊介绍： Hydrometallurgy aims to compile studies on novel processes, process design, chemistry, modelling, control, economics and interfaces between unit operations, and to provide a forum for discussions on case histories and operational difficulties. Topics covered include: leaching of metal values by chemical reagents or bacterial action at ambient or elevated pressures and temperatures; separation of solids from leach liquors; removal of impurities and recovery of metal values by precipitation, ion exchange, solvent extraction, gaseous reduction, cementation, electro-winning and electro-refining; pre-treatment of ores by roasting or chemical treatments such as halogenation or reduction; recycling of reagents and treatment of effluents.