难浸金精矿生物浸出体系的电位-pH图分析

摘要

Potential-pH (Eh-pH) diagram is an important means for thermodynamic analysis,it can reflect the various thermodynamic equilibriums in directly ways and help to determine the trends of chemical reactions.So the Eh-pH diagram plays an important guiding role in biological leaching refractory gold concentrate.In this article,the Eh-pH diagrams of FeS2-H2O,FeAsS-H2O system under the condition of 313 K,pH=0~7.0,E=-1.2~1.2 V were drawn by thermodynamic calculation and analyzed briefly.Results indicated that the stability zone of pyrite and arsenopyrite was respectively under potential of 0.336 V and 0.133 V in acidic solution,which means that arsenopyrite would be oxidized and dissolved at low potential.%电位-pH图是一种重要的热力学分析方法，能够直观地反映出浸出体系中的各种热力学平衡，有助于推断出物质发生化学反应的趋势，在难处理金精矿生物浸出体系中有重要指导作用。通过热力学计算，针对生物浸出环境绘制并分析了313 K温度下，pH=0~7.0，E=-1.2~1.2 V范围内适宜生物氧化黄铁矿-水系、毒砂-水系的电位-pH图。结果表明：在酸性体系下黄铁矿的稳定区域存在于0.336 V以下，毒砂则为0.133 V以下，毒砂的稳定性比黄铁矿的稳定性低，在较低的电位条件下便会被氧化溶解。