金在铜(Ⅱ)-乙二胺-硫代硫酸盐浸金体系的电化学氧化机理  

Electrochemical Oxidation Mechanism of Gold in Copper(Ⅱ)-ethylenediamine-thiosulfate Gold Leaching System

作　　者：唐家华 李佳蕊 字富庭[1] 张炎 TANG Jiahua;LI Jiarui;ZI Futing;ZHANG Yan(Faculty of Science,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]昆明理工大学理学院,昆明650500

出　　处：《有色金属工程》2024年第1期51-60,共10页Nonferrous Metals Engineering

基　　金：国家自然科学基金资助项目(52264031);云南省基础研究专项(202301AT070195);昆明理工大学分析测试基金(2022T20210101)。

摘　　要：硫代硫酸盐因无毒、高效等优点被认为是浸金工艺中最具应用前景的提金技术。采用电化学测试方法(开路电位、循环伏安、Tafel曲线及电化学阻抗)探究了金电极在Cu^(2+)-en-S_(2)O_(3)^(2-)浸金体系中电化学行为,并利用拉曼光谱和XPS对金电极的表面氧化产物进行表征,阐明金在Cu^(2+)-en-S_(2)O_(3)^(2-)体系中的氧化机理。结果表明:S_(2)O_(3)^(2-)能够促进金表面氧化,并且在本文电化学条件下,当金电极在5 mmol/L Cu^(2+)-10 mmol/L en-100 mmol/L S_(2)O_(3)^(2-)体系时,反应速率由电荷转移这一步骤控制。体系中硫代硫酸盐浓度通过影响其表面性质和表面反应速率来控制金的溶解情况。并阐明了金电极在Cu^(2+)-en-S_(2)O_(3)^(2-)浸金体系中电化学氧化机理,为金浸出试剂成分的调控提供了理论依据。Thiosulfate is considered to be the most promising gold extraction reagent in gold leaching process due to its advantages of non-toxicity and high efficiency.The electrochemical behavior of gold electrode in Cu^(2+)-en-S_(2)O_(3)^(2-)gold leaching system was investigated by electrochemical testing methods(open circuit potential,cyclic voltammetry,Tafel curve and electrochemical impedance).Characterization of surface oxidation products of gold electrodes using Raman spectroscopy and XPS,and the oxidation mechanism of gold was clarified.The experimental results show that S_(2)O_(3)^(2-)can promote the oxidation of the gold surface,and under the electrochemical conditions in this paper,the reaction rate is controlled by the step of charge transfer when the gold electrode is in the 5 mmol/L Cu^(2+)-10 mmol/L en-100 mmol/L S_(2)O_(3)^(2-)system.The thiosulfate concentration in the system controls the dissolution of gold by affecting its surface properties and surface reaction rate.The electrochemical oxidation mechanism of gold electrodes in the Cu^(2+)-en-S_(2)O_(3)^(2-)leaching gold system was this paper elucidated,and a theoretical basis was provided for the regulation of the composition of gold leaching reagents.

关 键 词：金 浸出 硫代硫酸盐 电化学 氧化机理 

分 类 号：TF831[冶金工程—有色金属冶金]