硫代硫酸盐浸金电化学研究 (Ⅱ)阴极行为及浸金机理

来源期刊：中南大学学报(自然科学版)1993年第2期

论文作者：姜涛 许时 陈荩

文章页码：174 - 180

关键词：硫代硫酸盐; 浸出; 金; 电化学; 阴极过程

Key words：thiosulfate; leaching; gold; electrochemistry; cathodic process

摘    要：研究硫代硫酸盐浸金的阴极行为及浸出机理。结果表明,在铜氨络离子存在的硫代硫酸盐溶液中,二价铜氨络离子在金粒表面得到电子被还原,生成的一价铜氨络离子进入溶液后被氧化再生为二价铜氨络离子,后者又到金粒表面上还原。根据阳、阴极过程电化学研究的结果,提出了氨性硫代硫酸盐溶液浸金的电化学-催化机理及模型,揭示了铜离子和氨在硫代硫酸盐浸金过程中的作用、作用条件和机理。

Abstract: The behaviour of cathodic process of leaching gold with thiosulfate has been investigatedin this paper.Results show that it is Cu(NH₃)₄²⁺ that is reduced directly on gold surface andoxygen has a predominate effect on the cathodic process.Based on results of electrochemicalstudy on gold dissolution,an electrochemical-catalytical mechanism has been proposed to i-dentify the leaching of gold with ammoniacal thiosulfate.Ammonia reacts with gold ions onanodic surface of gold;the formed Au(NH₃)₂⁺ is substituted by S₂O₃^2- after entering solutionto form more stable Au(S₂O₃)₂^3-;Cu(NH₃)₄²⁺ gets electrons on the cathodic surface and isreduced to Cu(NH₃)₂⁺,which is then oxidized by oxygen and regenerated into Cu(NH₃)₄²⁺ af-ter entering the solution.This mechanism has been confirmed by electrochemical approach and technological investigation.