中高温浸矿菌结合对高砷铜精矿的浸出研究

利用自主选育的耐高砷中高温浸矿菌浸出以砷黝铜矿为主的高砷铜精矿(As 4%～5%, Cu＞20%)。采用前期中温浸矿菌, 后期高温浸矿菌的两段法生物浸出10 d, 总铜浸出率可达90.01%。对浸渣的铜物相分析可知: 高温菌对黄铜矿的浸出率可达78.45%, 是中温浸矿菌14.2%的5.5倍以上; 对砷黝铜矿的浸出率为33.42%, 约为中温浸矿菌17.48%的2倍。对原生硫化铜矿的浸出率总计为50.24%, 约为中温浸矿菌16.26%的3倍。高温菌对砷黝铜矿的氧化作用较黄铜矿差; 中温浸矿菌对As³⁺ 和As⁵⁺的耐受力比高温菌强。在两段法浸出前期添加2.0 g/L的 Fe³⁺ 或2.5%的黄铁矿精矿细菌培养液均能提高中温浸矿菌的浸出速率。     

硫化矿生物冶金研究进展

对硫化矿生物冶金进行了较全面的综述，包括浸矿微生物种类及培养条件、硫化物细菌氧化机理、氧化亚铁硫杆菌的铁硫氧化系统、浸矿工艺、影响浸矿效果的主要因素以及浸矿细菌的分子生物学。介绍了国内外生物冶金的工业化应用现状。提出了我国硫化矿生物冶金需要解决的主要问题。     

生物浸矿领域中功能微生物的研究进展

微生物浸出技术是一种新型的环境友好型湿式冶金技术，可以作为解决高品位矿产储量缩减和尾矿堆存数量增加等难题的潜在有效途径。具有浸矿功能的微生物在生物浸矿过程中有着举足轻重的作用。根据浸矿微生物的营养代谢类型可以将微生物分为自养代谢微生物和异养代谢微生物2大类，归纳总结了不同类型微生物在生物浸矿过程的最佳浸矿条件、浸出效率和浸出机理。自养微生物主要用于浸出硫化矿，其中氧化亚铁硫杆菌应用最为广泛，且混合菌的浸出效率高于单一菌的浸出效率；而异养微生物主要用于浸出非硫化矿，介绍了硅酸盐细菌、产氨细菌和真菌在浸矿领域中的功能。在此基础上，提出了高效浸矿功能微生物未来存在突破可能的研究角度：原位驯化与分离筛选功能微生物、构建与应用基因工程菌株、设计与优化特异性培养基、推进异养浸矿微生物的深入研究与实际应用、菌群共代谢调控及菌剂研发等。     

生物冶金常用浸矿菌种及改良育种的基本方法

介绍了生物冶金常用浸矿菌种嗜中温菌、中等嗜热菌和极端嗜热菌的生理生化特性，并针对目前工业用菌自然选育及驯化现状，提出改良育种的基本方法和操作步骤及改良育种工作中需要注意的问题。     

生物冶金中混合菌的作用

生物冶金环境中的微生物是多样的,至今已经报道有13个属的细菌能够氧化浸出金属硫化物。细菌浸出金属硫化物有间接浸出、接触浸出和协作浸出3种作用机制,其中间接浸出又有硫代硫酸盐和多硫化物2种作用途径。在生物冶金过程中使用混合菌较使用单一菌有很多优势,但使用混合菌也有一些不利因素。混合菌的浸矿机制还不是很明确,因此,为了更好地利用生物冶金技术,应加强有关混合菌的研究,以便能控制混合菌的组成和活性,使生物浸出过程达到最优化。     

生物浸矿领域中功能微生物的研究进展

微生物浸出技术是一种新型的环境友好型湿式冶金技术,可以作为解决高品位矿产储量缩减和尾矿堆存数量增加等难题的潜在有效途径。具有浸矿功能的微生物在生物浸矿过程中有着举足轻重的作用。根据浸矿微生物的营养代谢类型可以将微生物分为自养代谢微生物和异养代谢微生物2大类,归纳总结了不同类型微生物在生物浸矿过程的最佳浸矿条件、浸出效率和浸出机理。自养微生物主要用于浸出硫化矿,其中氧化亚铁硫杆菌应用最为广泛,且混合菌的浸出效率高于单一菌的浸出效率;而异养微生物主要用于浸出非硫化矿,介绍了硅酸盐细菌、产氨细菌和真菌在浸矿领域中的功能。在此基础上,提出了高效浸矿功能微生物未来存在突破可能的研究角度：原位驯化与分离筛选功能微生物、构建与应用基因工程菌株、设计与优化特异性培养基、推进异养浸矿微生物的深入研究与实际应用、菌群共代谢调控及菌剂研发等。     

高温高硫铜矿原地破碎微生物浸出理论与实践

原地破碎微生物浸矿技术是将采矿爆破技术与生物冶金技术有机结合而形成的一种井下就地提取矿物有用组分的新型采冶工艺技术,为了开发利用东同矿业公司赋存的大量高温高硫低品位硫化铜矿,北京矿冶研究总院和江西东同矿业公司合作,进行了"高温高硫铜矿原地破碎微生物浸出试验研究"项目研究,内容涉及矿石溶浸化学、浸出动力学、计算机渗流模拟、布液参数优化、集液工程设计、原地爆破技术、微生物浸矿过程研究、全流程成本控制等诸多方面。经过5年系统、全面的研究试验工作,形成了适应于地下矿山原地破碎细菌浸出开采回收的完整生产技术,首次实现了原地破碎细菌浸出开采技术在我国有色矿山的成功应用,取得了良好的经济效益和明显的社会效益。     

两种优势菌浸矿机理及动力学研究概况

氧化亚铁硫杆菌是生物浸矿技术中研究较为成熟的、在中温环境中的优势菌,而近年研究发现了另一种中度嗜热环境中的优势菌--嗜铁钩端螺旋菌.由于这两种菌在生物学特性上有较多相似之处,本文综述两种菌的浸矿机理和动力学方面的研究现状,并对其存在问题和今后主要研究方向进行探讨,以期为生物浸矿技术的具体工程运用提供指导.     

铜矿石生物溶浸的现状和前景

生物溶浸中微生物充当氧化反应的生物催化剂,并使硫化矿溶解。作为一种成功的回收金属的工艺,生物溶浸与湿法冶金一样能达到下列效果:①回收湿法冶金所能回收的铜和其它贵金属;②回收有用形式的硫和铁,或以无害产物的形式排除它们;③在处理硫化铜矿物(黄铜矿除外)方面,具备一定的灵活性,另外还能处理其它有色金属(如锌、铅)硫化物。可根据简称为“直接浸蚀”和“间接浸     

硫化矿的生物冶金及其研究进展

生物冶金由于其生产成本低、投资少、工艺流程短、设备简单、环境友好、能处理复杂多金属矿物等优点,今后可望在湿法冶金中起到更大作用.目前,生物冶金技术已广泛应用,并在铜的提取上实现了工业应用,同时科学工作者对于生物冶金中的微生物及生物浸出过程的机理展开了大量研究工作.本文较系统地介绍了国内外生物冶金的发展概况,归纳了关于浸矿微生物的种类及其作用的研究状况,讨论了微生物冶金过程的直接作用、间接作用,论述了细菌浸出过程的原电池效应及硫化矿氧化过程电化学机理的研究,归纳了关于硫化矿生物冶金的研究进展.     

Salt-tolerant microorganisms potentially useful for bioleaching operations where fresh water is scarce

Anions and cations can accumulate in process waters due to the source water, to evaporation and because of gangue mineral dissolution. Common salts that can accumulate from mineral gangues are the anions, chloride and sulfate, both of which impact on microorganisms used in bioleaching processes. The search for salt-tolerant acidophilic microorganisms able to tolerate high concentrations of these salts, as well as high concentrations of metals, has been underway for at least 20 years because their application would considerably improve bioleaching process efficiency in areas where fresh water is scarce.A thorough search of microorganisms from saline and acidic drains, lakes and sediments in the South West of Western Australia and a CSIRO culture collection was undertaken to bio-prospect for salt-tolerant bioleaching cultures. Pure strains of common bioleaching acidophiles did not tolerate seawater salinities, however, enrichment cultures of mesophilic acidophilic microorganisms that could tolerate up to 70 g/L sea salts and 350 g/L MgSO₄⋅7H₂O were established. The salt tolerance of acidophiles was less in thermophilic temperature ranges, compared with mesophilic and moderately thermophilic temperature ranges. Tolerance to sulfate salts was greater than chloride with magnesium ions likely limiting maximum sulfate tolerance. Iron oxidising cultures were more sensitive than sulfur oxidising cultures to higher chloride concentrations. The addition of pyrite to enrichment cultures increased salt tolerance. The efficacy of the salt tolerant cultures to extract copper will be determined in bioleaching experiments with chalcopyrite ore and salty process water.     

微生物技术在矿物选冶过程中的研究进展

由于矿物逐渐被开采,优质矿物资源日益短缺,“贫、细、杂” 矿物的选别回收亟待解决,人们对选矿技术的要求越来越高。一些特殊的微生物本身或者其代谢物可以将矿物中的离子溶解出来,或者改变矿物的表面性质,并且,与传统选矿药剂和浸出剂相比,微生物具有成本较低,对后续环境污染小的优势,因此,微生物浮选和微生物冶金技术得到了快速的发展。本文介绍了国内外对微生物浸出、氧化、分解和微生物在矿物表面的吸附、化学反应及微生物细胞表面化学等方面的研究进展。      

铜萃取界面乳化液中浸矿微生物的多样性

界面乳化是溶剂萃取过程中难以避免的现象,显微观察发现在铜萃取界面乳化液中存在形貌复杂多样的微生物。利用16s rRNA基因测序技术对铜萃取界面乳化液中微生物种群结构进行分析,结果发现包括Leptospirillum sp,Acidithiobacillus ferrooxidans,Metallibacterium sp,Staphylococcus sp在内的7类细菌,其中优势菌种为Leptospirillum sp.E4-L9和Acidithiobacillus ferrooxidans ATCC 23270,两者在乳化液细菌中分别占到40.48%和38.1%。利用Fe2+和硫作为能源对界面乳化液中的微生物进行分选,进一步分析种群结构。铜萃取界面乳化对浸矿细菌有截留作用,从而会降低生物浸矿效率。     

磷矿的微生物浸出研究进展

磷矿不仅是一种化工矿物原料,更是一种重要的战略资源。在我国磷矿资源日益短缺和环境污染问题日趋严重的大背景下,科学、合理地利用宝贵的磷矿资源是解决这一问题的有效途径。与传统工艺相比,微生物冶金技术有成本低、能耗低、流程简单和环境友好等特点,在低品位难选冶的矿产资源的开发中有着广阔的应用前景。介绍了目前我国磷矿资源的特点和现有的浸矿微生物种类;接着对比了各个菌种浸矿的特点,发现中等嗜热菌为浸矿效果最好的菌种,二步浸出效果明显优于一步浸出。分析了细菌的浸矿优势、发展历史和研究现状,详细介绍细菌在浸出磷矿过程中的作用机理。指出微生物浸矿存在的问题及改进方法,对微生物选冶技术的发展前景进行了展望。      

浸矿微生物鉴定研究进展

为了探明浸矿过程中微生物的组成,通过比较浸矿微生物鉴定的常规方法、免疫学方法和分子生物学方法的优缺点,并参考研究现状,指出利用现代分子生态学的方法可快速鉴定浸矿微生物,多种方法组合使用可获得更加全面的浸矿微生物组成演替信息。     

Determining the effect of acid stress on the persistence and growth of thermophilic microbial species after mesophilic colonisation of low grade ore in a heap leach environment

The microorganisms involved in the bioleaching of sulphidic mineral ores are acidophilic. Generally, a pH in the range of pH 1–2.5 is applied for optimal growth in these systems. In operating heaps, perturbation of conditions could result in changes in the pH outside this “safe” window, so an understanding of the effect of changes in pH on growth and activity of bioleaching microbes is needed. Previous work has shown that some microorganisms e.g. Acidithiobacillus thiooxidans, Leptospirillum ferriphilum and Leptospirillum ferrooxidans are able to adapt to low pH environments (∼pH 0.9). However, most studies on the response of micro-organisms implicated in mineral bioleaching to pH have been conducted under submerged, aerated culture conditions, with limited performance-based studies conducted under conditions mimicking a heap environment. In this study, the effect of acid stress on the persistence of the thermophilic micro-organisms in the ore bed inoculated at mesophilic conditions and their subsequent growth on reaching thermophilic conditions is considered.Following inoculation, five columns loaded with a low grade chalcopyrite ore were irrigated at a feed pH of 1.7 at 25 °C. After a few days, the temperature was sequentially increased from 25 °C through 37 °C to 50 °C, resulting in an Eh above 850 mV across all columns. The irrigation feed pH was then varied across the range pH 1.0 to 1.7 at 50 °C. Eh values greater than 800 mV could be attained in the columns with feed pH values between pH 1.2 and pH 1.7 at 50 °C. The Eh of the column receiving feed solution at a pH of 1.0 at 50 °C dropped to below 700 mV and did not recover. The temperature was then increased gradually to 60 °C. All the columns with feed pH of 1.2 and higher achieved Eh values above 800 mV. Quantitative analyses of the microbial community on selected PLS and ore samples indicated that lower pH affected the persistence of the thermophilic micro-organisms in the ore bed and their subsequent growth on reaching thermophilic conditions. The microbial population detached from the ore sample after 120 days decreased by a factor of 5–15 and 25–100 fold on decreasing the operating pH from 1.5–1.7 to 1.4 and 1.2 respectively. Poor microbial activity was found at pH 1.0, suggesting ineffective growth or persistence of the archaea.     

国外生物氧化提取技术的进展

从资源经济、合理开发利用角度出发,对生物氧化提取技术的研究与应用进行了论述,并重点对国外在该领域的工业应用作了比较详尽的说明。该技术在工业化已经应用到铜、金、铀、钴的回收。由于生物氧化及浸出技术的工业应用投资少,生产费用低,适合于处理低品位及难处理的矿石,对生态环境无影响,因而具有很好的工业应用前景。     

硫化铜矿生物堆浸研究进展

就当前硫化铜矿生物堆浸技术的研究热点优良浸矿微生物的选育和堆浸工艺参数的优化进行了综述;作为实例,介绍了了美国Kennecott铜矿的黄铜矿堆浸工艺和我国紫金山铜矿的辉铜矿堆浸工艺。     

Enrichment and characterisation of thermophilic acidophiles for the bioleaching of mineral sulphides

Thermophilic acidophilic Archaea were enriched from samples collected from geothermally active sites in Papua New Guinea. Pure cultures (JP2 and JP3) were obtained from mixed culture enrichments and were characterised and tested for their bioleaching ability. All cultures possessed Sulfolobus-like morphology, and the presence of distinctive cyclized tetraether lipids. The two pure cultures were identified by their 16S rRNA gene sequences as being most closely related to Sulfolobus solfataricus. Each isolate was able to oxidise both Fe²⁺ and sulphur, and grow on both pyrite and chalcopyrite under autotrophic conditions. Leaching experiments showed that the isolates were capable of rapidly leaching a chalcopyrite concentrate (up to 91% Cu release in 108 h). Optimal temperatures for growth and chalcopyrite leaching were determined for each strain. Chalcopyrite dissolution rates for JP2 at different temperatures were determined using a previously described kinetic model. An Arrhenius plot to investigate the relationship between dissolution rate and temperature, showed that for JP2, an increase in temperature from 70 to 83 °C resulted in a 6.6-fold rate increase. Studies with both mixed and pure cultures showed that these cultures were capable of rapidly leaching a chalcopyrite concentrate at very high temperatures (up to 90 °C), but also were capable of bioleaching at 50 °C. These thermophilic acidophiles possess the ability to bioleach over a wide range of temperatures. They are potentially well suited to industrial leaching applications where considerable temperature fluctuations limit the growth of other non-thermophilic bioleaching microorganisms.