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IMPROVEMENT OF BIOLEACHING EFFICIENCY BY THE GAS PHASE CONTROL

通过气相控制提高生物浸出效率

基本信息

批准号：
09555316
负责人：
INOUE Chihiro
金额：
$ 7.94万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

In this study, it was examined that ratio of gas composition supplied reaction chambers was controlled in order to improve the efficiency of the bioleaching. First, the effect of ratio of concentration of gas composition on ferrous ion oxidizing activity of Thiobacillus ferrooxidans was examined. Ferrous ion oxidizing activity was most improved at 7% of carbon dioxide concentration and 5〜10% of oxygen concentration. Bioleaching with Leptospirillum ferrooxidans was carried out, using the pyrite as a model sulfide mineral. It was possible that the pyrite almost perfectly dissolved, while the generation of the sulfuric acid in the leaching was suppressed. Bioleaching experiments on the copper concentrate including poor solubility copper minerals such as enargite and chalcopyrite were also carried out. When the concentrate was not treated with silver ion, only pyrite was dissolved and copper minerals were not almost dissolved. When the bio leaching was carried out, after this concentrate was treated with silver ion, the dissolution of copper minerals was promoted and the dissolution of the pyrite was suppressed. It was proven that both of substitution reaction in mineral surface by silver ion and oxidation reaction by ferric ion were necessary to promote the dissolution of these copper minerals. Since Thiobacillus ferrooxidans and/or Leptospirillum ferrooxidans rapidly reproduces the ferrous ion produced by the mineral dissolution with ferric ion, the control of the gas composition is important in order to promote this regeneration reaction. Though in the conventional pyrometallurgy method, the processing of the copper concentrate including arsenic minerals was difficult, the handling in the real operation becomes possible by bioleaching method developed this time.

在这项研究中，它被检查，以提高生物浸出的效率，控制供应的气体组合物的反应室的比例。首先，考察了气体组分浓度比对氧化亚铁硫杆菌亚铁离子氧化活性的影响。当二氧化碳浓度为7%，氧气浓度为5 ~ 10%时，亚铁离子氧化活性提高最大。以黄铁矿为模型硫化矿物，采用氧化亚铁纤梭菌（Leptoacillum ferrooxidans）对黄铁矿进行生物浸出，黄铁矿几乎完全溶解，浸出过程中硫酸的生成受到抑制。对含难溶性铜矿物硫砷铜矿和黄铜矿的铜精矿进行了细菌浸出试验。当精矿不经银离子处理时，仅溶解黄铁矿，铜矿物几乎不溶解。生物浸出时，该精矿经银离子处理后，促进了铜矿物的溶解，抑制了黄铁矿的溶解。证明了银离子在矿物表面的取代反应和铁离子的氧化反应是促进这些铜矿物溶解的必要条件。由于氧化亚铁硫杆菌和/或氧化亚铁小杆菌快速地再生通过矿物溶解与铁离子产生的亚铁离子，因此为了促进该再生反应，控制气体组成是重要的。虽然在传统的火法冶金方法中，含砷矿物的铜精矿的处理是困难的，但通过这次开发的生物浸出方法，在真实的操作中的处理成为可能。