添加Ag+和Cu2+强化硫化砷矿物生物浸出的研究
文献类型：学位论文
| 作者 | 郭佩 |
| 学位类别 | 硕士 |
| 答辩日期 | 2011-05-20 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 张广积 ; 杨超 |
| 关键词 | 雄黄 雌黄 Ag+ Cu2+ 生物浸出 |
| 其他题名 | Enhanced bioleaching of arsenic sulfide with the addition of Ag+ and Cu2+ |
| 学位专业 | 化学工程 |
| 中文摘要 | 随着金矿资源的开采利用，易处理金矿日益减少，难处理矿石中的金占黄金储量的比重不断增大。因此有必要对该种矿石进行预处理，提高黄金产量和收率。细菌氧化法作为一种矿物预处理新工艺，具有操作简便、投资少和环境友好等优点，近年来取得了较大发展。但细菌浸出也存在一些不足，如氧化速率慢、浸出周期长，在一定程度上降低了其成本优势。因此有必要对生物冶金的浸矿机理及强化手段进行深入研究，为工业应用提供理论指导。 本论文以雄黄和雌黄为目标矿物，嗜酸氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)和中度嗜热西伯利亚硫杆菌(Sulfobacillus sibiricu)作为浸矿菌株，对矿物可浸出性和催化剂强化浸出进行了系统研究。发现无催化剂时雄黄化学浸出和生物浸出的浸出率都偏低，硫酸铁不能有效氧化雄黄，雌黄的浸出率高于雄黄；添加Ag+可明显提高两种矿物的化学和生物浸出率；Cu2+需在较高温度下才对雄黄有明显催化效果，但生物浸出雄黄温度较低，所以Cu2+几乎没有催化作用；Cu2+对雌黄的浸出率高于Fe3+单独浸出及Cu2+与Fe3+联合浸出，添加Cu2+生物浸出雌黄时，At.f菌体系浸出率明显高于S.s菌体系。 考察了催化剂浓度、Fe3+浓度和浸矿温度等条件对浸出率的影响。化学浸出中，适当提高催化剂浓度和温度可提高浸出率，但过高后浸出率不再上升，甚至略有下降；较高的Fe3+浓度有利于浸出，因为催化剂再生反应在高Fe3+浓度下较易发生。 通过矿渣的XRD、SEM推测了雄黄催化反应机理：Ag+与Cu2+催化机理相似，矿物表面As被Ag+或Cu2+取代，生成Ag2S或CuS，然后被Fe3+溶解，实现催化剂离子再生和矿物的逐步溶解。 |
| 英文摘要 | Along with the exploitation of gold resources, the resource of gold ores which are easy to treat is gradually being depleted, making the proportion of gold resource of refractory gold ores increase. Therefore, pretreatment of refractory gold ores is necessary before direct cyanide leaching in order to enhance the leaching rate. Bioleaching is a mineral processing technique which is in great progress in recent years. Compared with other commonly applied techniques, bioleaching is the most promising one in the pretreatment of refractory gold ores for its great advantages of convenient manipulation, low operation cost and being benign to environment. However, there are drawbacks such as low gold recovery and long leaching time, which weaken the technical and economic advantages. So it is important to study in depth the bioleaching mechanism and the intensification methods to optimize industrial processes. In this work, At.f and a moderate thermophilic bacterium S.s were used to leach realgar and orpiment. The results show that in the cases of lack of catalytic ions, only very little realgar was leached both in the chemical leaching and bioleaching experiments, and ferric ion was not a very effective leaching agent, but the leaching efficiency of orpiment was better than that of realgar. The chemical leaching and bioleaching ratios of both minerals were improved significantly by adding Ag+ ions. Though the intensifying effect of Cu2+ on realgar was obvious at high temperature, the catalytic effect was negligible in practical situations because the bioleaching temperature of realgar was below 50℃. The orpiment leaching rate with Cu2+ was higher than both that with Fe3+ and that with both Cu2+ and Fe3+. With Cu2+, the bioleaching rate of At.f was much higher than that with S.s. The influences of the concentration of catalytic ions and Fe3+ and the temperature on leaching were investigated. During chemical leaching, the leaching fractions were enhanced with the increase of concentration of catalytic ions and temperature, but they stopped increasing, even declined slightly when the reaction conditions were raised excessively. High concentration of Fe3+ was favoured since the regeneration reaction of catalytic ions happened more easily under such a condition. The catalytic mechanisms of Ag+ and Cu2+ on realgar were inferred by XRD and SEM: surface arsenic was attacked by Ag+ or Cu2+, forming Ag2S or CuS, which was then dissolved by Fe3+ so that Ag+ or Cu2+ was liberated. The progressive catalytic dissolution of the realgar was realized through this cyclical process. |
| 语种 | 中文 |
| 公开日期 | 2013-09-24 |
| 页码 | 55 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1741]  |
| 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 | 郭佩. 添加Ag+和Cu2+强化硫化砷矿物生物浸出的研究[D]. 中国科学院研究生院. 2011. |
入库方式： OAI收割
来源：过程工程研究所
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