砷黄铁矿生物氧化热力学分析  

Thermodynamic analysis of bio-oxidation of arsenopyrite

作　　者：李骞[1] 韩雨琪 张雁[1] 杨永斌[1] 姜涛[1] LI Qian;Han Yuqi;ZHANG Yan;YANG Yongbin;JIANG Tao(School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学资源加工与生物工程学院,湖南长沙410083

出　　处：《中南大学学报(自然科学版)》2025年第1期1-10,共10页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2023YFC2907801);湖南省科学技术厅自然科学基金青年基金资助项目(2023JJ40760)。

摘　　要：生物氧化法是各类含砷金矿预处理方法中最具发展前景的方法之一,然而,生物氧化速率慢、周期长,且含砷金矿中砷黄铁矿(FeAsS)作为最主要的载金矿物在生物氧化过程中,其表面易形成钝化物,这些问题严重制约含砷金矿生物预氧化技术的工业化应用。针对以上问题,本文从热力学角度出发,分析FeAsS的氧化溶解及钝化过程。研究结果表明:在pH为0~3,电位-0.4<E<0.2 V(pH=3)或-0.4<E<0.4 V(pH=0)时,FeAsS在氧化过程中不可避免地会形成中间钝化产物As_(2)S_(2)、As_(2)S_(3)和S0;通过提高溶液电位可使这些钝化产物不能稳定存在;当E>0.2V(pH=3)或E>0.4V(pH=0)时,FeAsS会被氧化生成含Fe沉淀物,其中,H_(3)OFe_(3)(SO_(4))_(2)(OH)_(6)和FeO∙OH最容易形成;在实际氧化过程中,应尽量控制溶液电位不宜过高或尽量减少体系的总硫浓度,以避免含铁钝化物的生成。该热力学分析可为砷黄铁矿的高效生物氧化提供参考。Bio-oxidation is regarded as one of the most promising methods for pretreating various As-containing gold ores.However,due to the formation of passivating products on the surface of arsenopyrite(FeAsS)which is the predominant auriferous mineral in As-containing gold ores,and the issues of slow rate and long periods of bio-oxidation,the large-scale industrial application of this bio-oxidation technology are severely impeded.To solve these problems,a series of thermodynamic calculations were employed to analyze the oxidative dissolution and passivation behavior of FeAsS.The results show that under acidic conditions(pH=0-3)the intermediate passivating products of As_(2)S_(2),As_(2)S_(3),and S0 are inevitably formed from the oxidation of FeAsS at E scale of-0.4 V to 0.2 V(pH=3)or 0.4 V(pH=0).These passivating products can be unstable by increasing E(>0.2 V(pH=3)or>0.4 V(pH=0));at this time,the Fe precipitates can be formed,of which H_(3)OFe_(3)(SO_(4))_(2)(OH)_(6) and FeO∙OH are most likely to be formed from the FeAsS oxidation.Therefore,the solution potential should be controlled not to be too high or the total sulfur concentration of the system should be minimized to avoid the formation of Fe-containing passivation products.This thermodynamic analysis can provide theoretical guidance for the efficient biological oxidation of arsenopyrite.

关 键 词：含砷金矿 砷黄铁矿 生物氧化 钝化产物 热力学分析 

分 类 号：TF381[冶金工程—冶金机械及自动化]