硫代硫酸盐浸金体系中铜氨影响研究

Effect of Copper and Ammonia in Thiosulfate Gold Leaching System

采用方波伏安法(SWV)和Tafel曲线研究硫代硫酸盐浸金体系中硫代硫酸钠、氨、铜离子、Cu(NH_3)_4^(2+)的影响。结果表明,随着硫代硫酸钠浓度的增加,铜离子还原峰电流先增大后减小,当硫代硫酸钠浓度为0.10mol·L^(-1)时,铜离子还原峰电流最大;氨浓度为0.3 mol·L^(-1)时有利于金的浸出;在一定范围内增加铜离子浓度对金的浸出有利;当Cu(NH_3)_4^(2+)浓度为1.25mmol·L^(-1)时,硫代硫酸钠还原峰电流趋于稳定,表明铜与氨络合后形成的Cu(NH_3)_4^(2+)对硫代硫酸钠还原峰电流具有协同效应。

We studied the effects of sodium thiosulfate,ammonia,copper ion,and Cu（NH3）4^2＋ in thiosulfate gold leaching system by square wave voltammetry（SWV）and Tafel curve.The results showed that the reduction peak current of copper ion increased firstly and then decreased with the increase of the concentration of sodium thiosulfate,when the concentration of sodium thiosulfate was 0.10 mol·L^-1,the reduction peak current of copper ion reached the maximum value.The suitable concentration of ammonia was 0.3 mol·L^-1,and in a certain range,increasing the concentration of copper ion was benefit to leaching gold.When the concentration of Cu（NH3）4^2＋ was 1.25 mmol·L^-1,the reduction peak current of sodium thiosulfate tended to be stable,which indicated the formation of Cu（NH3）4^2＋ by complexation of copper ion with ammonia had a synergistic effect on the reduction peak current of sodium thiosulfate.