采用Eh-pH和物种分布图研究金在四种有机羧酸-硫代硫酸盐体系中的溶解热力学
Comparative thermodynamic analysis of gold dissolution in four organic carboxylic acid-catalyzed thiosulfate systems using Eh-pH and species distribution diagrams
陈俊南 1谢锋 1王伟 2白云龙2
作者信息
- 1. Key Laboratory for Ecological Metallurgy of Multimetallic Ores(Ministry of Education),Northeastern University,Shenyang 110819,China;Key Laboratory for Recycling of Nonferrous Metal Resources(Shenyang),Northeastern University,Shenyang 110819,China;School of Metallurgy,Northeastern University,Shenyang 110819,China
- 2. School of Metallurgy,Northeastern University,Shenyang 110819,China
- 折叠
摘要
无氨-硫代硫酸盐浸金体系因不使用氰化物或氨而被认为是一种有吸引力且环保的金浸出路线.本文通过热力学计算绘制了不同条件下铜-有机羧酸-硫代硫酸盐浸金体系的Eh-pH和物种分布图,对比研究了四种有机羧酸,包括草酸、苹果酸、柠檬酸和酒石酸在铜-硫代硫酸盐溶液浸金过程中的作用.结果表明,硫代硫酸盐是金离子络合的唯一有效配体,有机羧酸起到稳定铜离子的作用.与传统的铜-氨-硫代硫酸盐体系相比,铜-苹果酸/柠檬酸/酒石酸-硫代硫酸盐浸金体系具有更宽的浸出pH和更低的硫代硫酸盐消耗的潜在优势.四种有机羧酸体系中Cu(Ⅱ)/Cu(Ⅰ)的标准电位大小遵循如下顺序:E0[Cu(Ox)22-/Cu(S2O3)35-]>E0[Cu(NH3)42+/Cu(S2O3)35-]>E0[Cu2(Mal)2H-22-/Cu(S2O3)35-]≈E0[Cu2(Cit)2H-24-/Cu(S2O3)35-]>E0[Cu(Tart)2H-46-/Cu(S2O3)35-].提高硫代硫酸盐浓度会降低铜-有机羧酸配合物的含量,四种含铜配合物的稳定性按酒石酸>柠檬酸>苹果酸>草酸的顺序依次递减.
Abstract
The non-ammonia thiosulfate leaching system is considered to be an attractive and eco-friendly route for gold leaching without the usage of cyanide or ammonia.In this paper,the role of four organic carboxylic acids,named oxalic acid(Ox),malic acid(Mal),citric acid(Cit),and tartaric acid(Tart)in copper-thiosulfate system has been studied comparatively.Based on the available thermodynamic data,a series of Eh-pH and species distribution diagrams for copper-Ox/Mal/Cit/Tart-thiosulfate system under various conditions have been constructed from thermodynamic calculation.The results show that thiosulfate is the only effective complexing agent for aurous ions,while the organic carboxylic acids work as a copper ligand.The copper-Mal/Cit/Tart-thiosulfate system exhibits potential advantages over the traditional copper-ammonia-thiosulfate system,such as wider pH range and lower thiosulfate consumption.The calculation also indicates the redox potentials of Cu(Ⅱ)/Cu(Ⅰ)for the leaching systems are in the subsequence of E0[Cu(Ox)22-/Cu(S2O3)35-]>E0[Cu(NH3)42+/Cu(S2O3)35-]>E0[Cu2(Mal)2H-22-/Cu(S2O3)35-]≈E0[Cu2(Cit)2H-24-/Cu(S2O3)35-]>E0[Cu(Tart)2H-46-/Cu(S2O3)35-].Increasing thiosulfate concentration leads to a sharp decline in the content of copper-Ox/Mal/Cit/Tart complex,and the stability of the formed cupric complex follows the descending order of tartaric acid>citric acid>malic acid>oxalic acid.
关键词
金/硫代硫酸盐/热力学分析/有机羧酸Key words
gold/thiosulfate/thermodynamic analysis/organic carboxylic acid引用本文复制引用
基金项目
中央高校基本科研业务费专项(N182502044)
出版年
2024
NETL
NSTL
万方数据