摘要
采用硫脲法选择性地溶浸含金银的物料并通过电沉积的方法回收浸出液中的金银,可实现金银的有效提取并简化金银的提取流程。以含Fe3+5g/L、硫脲(TU)50g/L、pH 1的硫酸硫脲溶液分别浸出金、银及铜阳极泥中的金、银,所得浸出液中银、金与硫脲形成的配离子主要以[Ag(TU)4]+、[Ag(TU)3]+和[Au(TU)2]+形式存在。对硫脲浸出液的循环伏安研究结果表明,Fe3+、H+、[Au(TU)2]+、[Ag(TU)4]+和[Ag(TU)3]+在阴极电还原的起始电位分别为:0.15、-0.25、-0.32和-0.36V,因此金在阴极上优先于银被还原析出,继而与银同时还原析出,并伴随着氢气的析出、RSSR的还原和杂质金属的还原,而阴极析氢是降低电流效率的主要原因。
Thiourea method can realize effective extraction and simplify the extraction process of gold and silver ,by utilizing thiourea solution as leaching agent and electrodepositing gold and silver from the thiourea leaching solution .Sulphuric acid solution containing Fe3＋5 g/L ,thiourea（T U ）50 g/L and pH=1 is used to leach gold ,silver from pure gold ,pure silver and copper anode slim .The main thiourea complexes of silver and gold in the resulting leaching solution are [Ag（TU）4 ]＋ ,[Ag（TU）3 ]＋ and [Au（TU）2 ]＋ .The cyclic voltammograms of thiourea leaching liquid show s that the initial reduction potential of Fe 3＋ ,H＋ , [Au （T U ）2 ]＋ ,[Ag （T U ）4 ]＋and [Ag （T U ）3 ]＋ are 0 .15V ,-0 .25V ,-0 .32V and -0 .36V respectively . So gold is electrochemical reduced precipitation prior to silver ,then reduced with silver together ,and in company with H ＋ ,RSSR and other metallic impurities are reduced .However H2 evolution on cathode is the main reason for reducing the current efficiency .
出处
《重庆大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2014年第5期64-70,76,共8页
Journal of Chongqing University
基金
国家自然科学基金资助项目(51274108)
昆明理工大学2009年科研基金项目(KKZ4200727003)
关键词
金
银
电沉积
硫脲浸出液
电化学
循环伏安
gold
silver
electrodeposition
thiourea leaching solution
electrochemical
cyclic voltammograms
