氰化浸金过程中孔雀石反应的热力学  

Thermodynamics of Malachite in Gold Cyanide Leaching

作　　者：崔毅琦[1,2,3] 孟奇[1,2,3] 童雄[1,2,3] 董鹏[1,4] 

机构地区：[1]省部共建复杂有色金属资源清洁利用国家重点实验室,云南昆明650093 [2]昆明理工大学国土资源工程学院,云南昆明650093 [3]云南省金属矿尾矿资源二次利用工程研究中心,云南昆明650093 [4]昆明理工大学冶金与能源工程学院,云南昆明650093

出　　处：《稀有金属》2015年第7期637-642,共6页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51104077);云南省应用基础研究基金项目(2010ZC022)资助

摘　　要：针对氰化浸金过程中孔雀石的浸出反应进行热力学计算,分别绘制了在温度298.15 K、压强0.1 MPa条件下Cu CO3Cu(OH)2-H2O体系、Cu CO3Cu(OH)2-CN-H2O体系和Cu CO3Cu(OH)2-Au-CN-H2O体系的E-pH图,依据E-p H图中稳定区域的大小及其变化情况,分析了孔雀石氰化浸出过程中的热力学影响因素。结果表明:碱性环境下,当不存在络离子时,孔雀石不能溶解;Cu CO3Cu(OH)2-H2O体系中添加1×10-2mol·L-1CN-后,孔雀石能够在碱性溶液中溶解,固态孔雀石稳定区域缩小,铜氰络合物的稳定区域出现;当氰化物浓度由1×10-2mol·L-1提高到0.1 mol·L-1时,Cu(CN)-2的稳定区域消失,Cu(CN)2-3的稳定区域缩小,Cu(CN)3-4的稳定区域出现。研究发现碱性无氧环境中金可在孔雀石与氰根的共同作用下生成金氰络合物。另外,碱性环境下孔雀石与氰根反应的副产物(CN)2会氧化分解生成CN-和CNO-,同时CN-自身在氧气的作用下也会发生氧化反应。The thermodynamic calculations were performed for malachite leaching in the cyanide solution,and the potential-p H（ Ep H） diagrams of Cu CO3Cu（ OH）2-H2 O,Cu CO3Cu（ OH）2-CN-H2 O,Cu CO3Cu（ OH）2-Au-CN-H2 O were obtained at temperature of298. 15 K and pressure of 0. 1 MPa. Based on the stable region and the area changes of each material in the E-p H diagrams,the affecting factors of malachite leaching in cyanide solution were analyzed. The results showed that malachite was insoluble in the absence of complex ions in alkaline solution. And the stable region of copper cyanide complexes appeared and the stable region of solid malachite shrank with 1 × 10- 2mol·L- 1CN-being added to an alkaline Cu CO3Cu（ OH）2-H2 O system. With cyanide concentration increased from 1 × 10- 2to 0. 1 mol·L- 1,the stable region of Cu（ CN）-2disappeared,the stable region of Cu（ CN）2-3shrank and the stable region of Cu（ CN）3-4appeared. It was found that in an alkaline oxygen-free environment gold could be leached under the combined effect of malachite and cyanide. In addition,the by-products（ CN）2which was produced by the reaction between malachite and cyanide in alkaline environment could be decomposed into CN-and CNO-,and the oxidation reaction of CN-would occur with the presence of oxygen.

关 键 词：热力学 孔雀石 E-pH图 氰化浸金 

分 类 号：TD953[矿业工程—选矿]