| 题名 | 生物浸出难处理包金含砷矿物的机理研究 |
| 作者 | 罗志雄 |
| 学位类别 | 硕士 |
| 答辩日期 | 2007-06-02 |
| 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 | 中度嗜热嗜酸铁氧化菌 嗜酸氧化亚铁硫杆菌 包金含砷矿物 生物浸出 |
| 其他题名 | Mechanism of bioleaching of some gold-locking arsenic minerals in refractory gold containing concentrate |
| 学位专业 | 化学工程 |
| 中文摘要 | 采用生物浸出对难处理金矿进行预处理已经得到了初步的工业应用，与传统的焙烧氧化和加压氧化相比，含砷金精矿的细菌浸出具有设备简单、操作方便和有利于环境保护等特点。但细菌浸出也存在着一些不足和局限性，最主要的是由于采用的嗜酸氧化亚铁硫杆菌对矿物的浸出速度比较慢，造成氧化周期长，生成效率低。采用中度嗜温菌可以把目前的反应温度由35-40℃提高到50℃以上，能有效地提高反应速度，缩短反应周期，减少工厂的处理成本，但中度嗜温菌的浸出机理以及在矿浆环境中的生长耐受性和对矿物溶解释放的砷等有害元素的耐受性还需要进一步评价。 本论文以含砷金精矿、雄黄和雌黄作为目标矿物，通过中温菌MLY与常温菌At.f的浸矿比较，发现中温菌浸出效果较常温菌At.f要好，表现在有更高的铁、砷浸出率，更好的耐砷能力，达到相同的铁、砷浸出率下，所需的时间减少2天左右。 分别从矿浆浓度、接种量、原菌种和驯化菌浸矿等方面进行了考察，辅助以XRD、SEM和EDX等分析手段，结果证明：在含砷金精矿的细菌浸出过程中，中温菌MLY和常温菌At.f有不同的浸矿机理，MLY浸出主要是通过间接作用溶解的；At.f浸出过程中则既存在细菌吸附于矿物表面使得矿物的溶解的直接作用，也存在间接作用，但以直接作用为主。 研究了雄黄和雌黄的细菌浸出性能，发现当温度较低时，两种矿物具有较强的疏水性，导致At.f在雄黄、雌黄矿浆中很难生长繁殖，对矿物溶解几乎没有起作用；与常温菌不同，中温菌能够很好的生长繁殖，但对雄黄的溶解没有明显的作用；在浸出雌黄时，随着细菌的繁殖生长，矿物有明显的溶解。 |
| 英文摘要 | Bioleaching has been accepted as a commercial technique in the pretreatment of refractory gold ores. Compared with traditional technologies such as roasting and high pressure oxidation, bioleaching has advantages of simple equipment, convenient manipulation and being benign to environment. Acidithiobacillus ferrooxidans(At.f) which was widely used in current bioleaching plants could not leach the ore efficiently for its low leaching temperature. Application of moderate thermophiles which grow at 45-60℃ could leach the ore more rapidly for faster chemical reaction, thus reduced the leaching period and the operating cost. But the bioleaching mechanism of the moderate thermophiles may be different from that of At.f and further investigation is required. On the other hand, the poor ability of the thermophile to tolerate the toxicity of the soluble As, friction and shearing in the ore slurry could limit the application of the culture, so it is necessary to assess the toleration of the thermophile by experimental studies. In this work, At.f and a moderate thermophilic bacteria culture called MLY were used to leach refractory gold containing arsenic concentrate and the acclimated strains were cultured. The results showed that the acclimated MLY could leach the concentrate faster and needed less time at the same of concentration of iron and arsenic than At.f and the toxicity of the soluble As had little effect on the growth of the bacteria. The bioleaching mechanisms of arsenopyrite were investigated. The bioleaching experiments of arsenopyrite were carried out in which the different slurry densities, inoculations and strains were tested, and the residues were analysed by XRD, SEM and EDX. It was found that MLY and At.f showed different mechanisms during the bioleaching of the arsenopyrite: The indirect action was much more significant in MLY leaching, and in the case of At.f, both direct action and indirect action worked, but the direct action was much more significant than the indirect action. The leaching experiments of realgar and orpiment were performed with MLY and At.f. The results showed that At.f was unable to grow in the slurry possibly due to the hydrophobicity of the two minerals. Differing from At.f , MLY could grow well in the slurry, but only orpiment could be leached. In the case of realgar, though MLY sustained well in the slurry, little minerals could be leached. |
| 语种 | 中文 |
| 公开日期 | 2013-09-13 |
| 页码 | 82 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1143]  |
| 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 | 罗志雄. 生物浸出难处理包金含砷矿物的机理研究[D]. 过程工程研究所. 中国科学院过程工程研究所. 2007. |
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