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题名	含砷硫化矿物的生物浸出机理研究
作者	袁秋红
学位类别	硕士
答辩日期	2009-05-27
授予单位	中国科学院过程工程研究所
授予地点	过程工程研究所
导师	张广积
关键词	氧化亚铁硫杆菌 氧化硫硫杆菌 中度嗜热西伯利亚硫杆菌 雌黄 砷黄铁矿 生物浸出
其他题名	Studies on Bioleaching Mechanisms of Sulfide Minerals Containing Arsenic
学位专业	化学工程
中文摘要	难处理金矿是目前我国黄金工业的重要资源，难处理金矿中的金被砷黄铁矿、黄铁矿等伴生矿物包裹从而难以用传统工艺直接提取。细菌氧化预处理作为一种矿物处理新工艺，具有方法简单、投资少和对环境友好等优点，是近年来发展最快的难处理金矿预处理工艺。开展含砷金精矿、雌黄等包金含砷硫化矿物的生物浸出研究，加深对其细菌浸出机理的理解具有重要意义。 本论文采用氧化硫硫杆菌T.t和中度嗜热菌S.s浸出含砷金精矿，发现T.t菌和S.s菌均能对矿物进行有效浸出，T.t菌比S.s菌具有更好的耐高矿浆浓度能力；矿渣的XRD、SEM和电子能谱分析结果证明：砷黄铁矿经历“多硫化物”途径溶解，浸出后期硫覆盖物以及黄铁矾沉淀的形成，阻碍矿物的进一步氧化溶解；采用T.t菌浸出时矿物表面沉淀积累少，具有一定的浸矿优势；采用动电位极化、循环伏安电化学方法研究了砷黄铁矿—碳糊电极的电化学行为，揭示了砷黄铁矿的电化学氧化机理，并考察了温度和pH值对其电化学性质的影响。 以雌黄为目标矿物，通过常温菌At.f、T.t和中温菌S.s的浸矿比较，发现T.t和S.s具有较好的浸出效果，At.f很难在雌黄矿浆体系生长；氧化硫硫杆菌T.t和中温菌S.s浸出雌黄的机理不同：T.t浸出雌黄，主要通过细菌直接吸附到矿物表面使矿物氧化溶解，同时产生的硫酸促进矿物溶解过程；中温菌S.s浸出雌黄时细菌氧化产生的Fe3+对矿物溶解起主要作用，浸出体系中Fe3+的浓度直接影响到矿物的浸出效率；加入适量的表面活性剂吐温80≦10-5 g/L时，能改善矿物表面的润湿性，促进矿物浸出。 对含砷硫化矿物生物浸出机理和影响其浸出的各种因素的研究，为这类矿物生物湿法冶金技术的发展提供基础数据，对其进一步放大实验和工业应用具有指导意义。
英文摘要	Refractory gold ore is the main gold-containing mineral resources in China. In such ores, gold particles are enwrapped in many kinds of sulfide minerals mainly in arsenopyrite and pyrite, thus pretreatment is necessary before direct cyanide leaching. Bioleaching is a mineral processing technique which has made great progress in recent years. Compared with other commonly applied techniques, bioleaching is the most promising technique in the pretreatment of refractory gold ores for its great advantages of convenient manipulation, low operation cost and being benign to environment. So it’s of great importance to study on the bioleaching of gold-containing arsenic minerals such as arsenopyrite and orpiment and to understand the mechanism of biooxidation. In this work, T.t and a moderate thermophilic bacterium called S.s were used to leach arsenic-bearing refractory gold concentrate. The results showed that T.t and S.s could both leach the concentrate effectively and the T.t was more tolerable to the high slurry densities. The SEM, EDX and XRD analysis results of the leached residues indicated that the arsenopyrite was dissolved via polysulfide to elemental sulfur. Further oxidation of the residues was inhibited by the sulfur product and jarosite precipitates. It was found that leaching with T.t strains has its advantages for accumulating less product layer on the mineral surface. The electrochemical behaviors of the arsenopyrite were investigated to improve the understanding of the reaction mechanism using cyclic voltammetry and potentiodynamic scanning. The leaching experiments of orpiment were performed using At.f, T.t and S.s. The results showed that orpiment could leach by T.t and S.s, but At.f was unable to grow in the slurry. It was found that T.t and S.s showed different mechanisms during the bioleaching of orpiment. In the T.t leaching, the oxidation of the orpiment was mainly caused by the direct bacteria attachment onto the mineral surface and the dissolution process was accelerated by the forming of sulfuric acid. In the S.s leaching, the orpiment was dissolved by Fe3+ generated by bacterial oxidation and the leaching rate was closely related to the concentration of Fe3+. The leaching of orpiment could be enhanced by the addition of a small amount of surfactant tween-80 into the leaching liquor. The mechanism studies on bioleaching of sulfide minerals containing arsenic and investigation for a variety of factors which effect on leaching rate had provide the biooxidation technology fundamental information and basic data, and then advance its industrial application.
语种	中文
公开日期	2013-09-16
页码	85
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1277]
专题	过程工程研究所_研究所（批量导入）
推荐引用方式 GB/T 7714	袁秋红. 含砷硫化矿物的生物浸出机理研究[D]. 过程工程研究所. 中国科学院过程工程研究所. 2009.

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