【作者】 沈艳杰；

【导师】 龚文琪；

【作者基本信息】 武汉理工大学 ， 矿物加工工程， 2005， 硕士

【摘要】 生物技术在矿物加工中的应用是21世纪矿冶工程研究的前沿领域,它包括生物氧化浸出、还原浸出、代谢产物浸出及吸附等生物技术在矿物加工中的应用。铜、铀、金等的生物浸出已初步实现了工业化。据报道在美国超过25%的铜是由此法生产所得,在加拿大已有多个铀矿公司在进行这项工作。近年来,我国生物浸出的研究和应用也有了相当的发展,生物浸出技术已成功运用于江西德兴铜矿。目前,国内外有关矿物微生物技术的研究主要集中于金属矿,非金属矿方面的研究较少。尤其是生物还原浸出粘土矿物中铁(Fe3+)的研究国内还未见报导。本课题研究采用从江西德兴铜矿酸性矿坑水中提取,并经过富集培养的氧化亚铁硫杆菌(T.f.菌)作为菌源,经过驯化培养得到生命力和氧化性相对较强的浸矿菌种,以此菌种进行生物法去除高岭土体系中低价铁(Fe2+)的相关研究;利用纯培养的方法从粘土矿物(高岭土、云母原矿)中培养铁还原菌,以此菌种进行生物法去除粘土矿物中高价铁(Fe3+)的相关研究,以达到矿物提纯、增白的目的。研究表明,对低活性的T.f.菌进行富集培养、稀释法纯化培养,能够得到菌体大小均一、活性较高的T.f.菌。温度、pH值等因素对T.f.菌的生长有很大的影响,经过纯培养试验得出:细菌生长繁殖的最佳温度为30℃,最佳pH值为2. 0。T.f.菌在黄铁矿培养基中进行驯化培养试验,当pH在3. 5～4. 0、 细菌接种量为40%、温度为30℃、黄铁矿的含量为1. 0%时,驯化培养过程中T.f.菌氧化黄铁矿的效果最佳。以经过驯化培养的氧化亚铁硫杆菌作为浸矿菌种,采用摇瓶法与循环法两种方法进行实际高岭土的细菌浸矿试验研究,结果证明,采用循环法进行细菌浸矿的除铁、增白效果优于摇瓶法。对湖北某地高岭土矿进行循环法细菌浸矿试验,试验最佳条件为:pH值2. 0,细菌接种量40%,矿浆浓度3%。得到的处理效果为:高岭土原矿除铁率达77. 4%,白度从原来的72. 8%提高到83. 7%。利用人工配矿的方法在恒温、厌氧条件下进行纯培养,可得到使粘土矿物中Fe3+还原为Fe2+的异养微生物;试验证明,纯培养时加入糖的量与异养菌的活性大小成正比关系;加入赤铁矿的量对异养菌的活性也有较大影响。异养菌处理高岭土原矿30d时,粘土中Fe3+的去除率最大达到0. 60 mg/g clay。异养菌处理云母原矿15d时,粘土中Fe3+的去除率最大达到66. 4%。并且采用高岭土纯培养的铁还原菌处理云母的效果比利用云母本身培养得到的铁还原菌效果更为明显。理论研究方面,本文在分析、总结前人研究成果的基础上,结合自己的研究更多还原

【Abstract】 The application of biotechnology in mineral processing is the forefront research area in mining and metallurgical engineering in the 21st century, which includes the application of microbial oxidation leaching, microbial reduction leaching, metabolizing product leaching and microbial adsorption, etc. in the field of mineral processing.The microbial leaching of copper, uranium, gold, etc. has already been put into industrialized production. It is reported that over 25% of the copper is produced by microbial leaching in USA each year, and a lot of uranium ore companies are carrying out the same in Canada. In recent years, research and application of microbial leaching are under suitable development in our country. Microbial leaching technology has succeeded in application in Jiangxi Dexing Copper Mine.At present, the domestic and international research about the mineral biotechnology concentrates on the metallic ores mainly, and there is much less research in the fields of non-metallic ores. It is especially true that research about the microbial leaching of iron (Fe³⁺) in clay minerals appears very rare.This research adopts T. ferrooxidans as the bacterium source that has been collected and separated from the acid mine drainage of Jiangxi Dexing Copper Mine, and has been enriched through cultivation. The bacterium strains got vitality and relatively strong oxidizing leaching activity through taming. By this method, the relevant research focusing on removing the Fe²⁺ from kaolin system was carried out. Utilizing the pure cultivation method, the iron-reducing bacteria were obtained from the clay minerals （kaolin and mica ores）. The relevant research focusing on removing Fe³⁺ from the clay minerals by these bacteria was carried out, in order to achieve the purpose of mineral purification and whitening.Studies have shown that T. ferrooxidans with high activity and uniform size can be obtained by dilution purification cultivation and enrichment cultivation. Factors such as temperature and pH value etc. have very great influence on the growth of the bactera. The purification cultivation experiments have shown that the bacteria grow best when the temperature is 30℃ and the pH value is 2.0. The taming cultivation experiments of T. ferrooxidans in the pyrite culture medium show that when pH is3.5⁴.0, the bacterial inoculating amount is 10%, temperature is 30°C, and the concentration of pyrite is 0.5%, the result of pyrite oxidation by T. ferrooxidans is the best.The experiments adopting T. ferrooxidans got by taming cultivation as leaching bacterium, and the contrastive tests between the shaking-bottle method and the recycling bio-reactor method were preformed under the same condition. The experiments show that the bacterial leaching result of kaolin by the recycling bio-reactor method is better than that by the shaking-bottle method. Through the investigation, the optimum conditions of treating kaolin of a Hubei mine have been obtained. The pH value is about 2.0, the bacterial inoculating amount is 40%, and the pulp concentration is 3%. The treatment results show that the iron-removal rate of kaolin reachs 77.4%, and the whiteness is from 72.8% up to 83.7%.Heterotrophic micpobes that can reduce Fe3+ in clay into Fe2+ can be obtained by the method of pure cultivation in artificial mineral mixture under constant temperature and anaerobic conditions. The experiments show that under the conditions of pure cultivation the activity of the heterotrophic microbes is in direct proportion to the amount of the sugar addition. The addition of hematite also has significant influence on the activity of the heterotrophic microbes. After treating the kaolin ore with the heterotrophic microbes for 30 d the rate of removal of Fe3+ in clay attained up to 0.60 mg/g clay. After treating the mica ore with the heterotrophic microbes for 15 d the rate of removal of Fe3+ in clay attained up to 66.4%. In addition, better results were achieved when treating the mica ore with the iron-reducing bacteria cultivated in the kaolin medium than that更多还原