生物氧化预处理后采用硫代硫酸盐浸滤从难处理含碳硫化物硫石中回收金

纽蒙特金公司利用矿物氧化细菌的能力开发了用于低金硫化物和含碳硫化物难处理金矿石的预处理技术。生物氧化过程使硫化矿物氧化导致金的暴露面的扩大，从而有利于下一步的回收。生物氧化的含碳硫化物矿石不能用氰化物堆摊浸滤。这是由于矿石中含碳物质的夺金特性所致。因而研制了硫代硫酸铵堆摊浸滤从这些夺金的经生物氧化的矿石中萃取充代硫酸铵浸滤过程已在实验室和半工业试验中成功应用。得到了满意的结果，激励了此项技术的继续     

微生物在矿物与金属工业中的应用

生物技术在矿物与金属工业中的重要性日益增长 ,将来它会在采矿区复原方面起到同样重要的作用。最近由英国矿物工业研究组织( MIRO)出版的技术报告微生物在矿物与金属工业中的应用 ,对其最新进展作了综合而及时的评述。各种生物技术开发的驱动力是追求“洁净技术”。 MIRO称 ,生物技术在矿物与金属工业中的应用主要有两大类 :生物浸出 /矿物的生物氧化和生物复原与回收。人们早已发现细菌以及相似的但在生物学上无关的生物体具有氧化金属硫化物的能力 ,应用其能力的 4种工业方法是 :矿石堆浸、废石场堆浸、就地浸出和反应器浸出。目前的…     

生物预氧化—酸性硫脲浸金联合工艺

详细介绍了生物预氧化技术的原理、硫脲浸金法的反应机理和研究进展,以及生物预氧化—酸性硫脲浸金联合工艺的研究现状及其应用前景。采用生物预氧化—酸性硫脲浸金联合工艺处理新疆某低品位难处理金矿,对影响硫脲浸金的因素进行了实验探索,得到了该体系下较优的硫脲浸出条件为:温度25℃、pH值1.5、液固比5∶1、硫脲浓度25kg/t、浸出时间5h、搅拌速度350r/min,金浸出率最高可达97.84%。     

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.     

矿业中的生物技术

生物技术将是２１世纪的主流，本文综述微生物氧化浸出、还原浸出、代谢产物浸出及吸附等生物技术在金属矿加工，提取及废弃物处理方面的研究和应用现状及工业前景，并对硫化精的生物浸出的反应速度及反应器进行了讨论。     

应用阶段隔离式氧化沟技术进行二级处理及生物营养物深度去除

阶段隔离式氧化沟技术为丹麦克鲁格公司与丹麦工业大学联合研究开发的一种新型氧化沟技术。该技术将常规氧化沟工艺与序批式活性污泥法技术融为一体，从而使其既可满足二级处理要求，又能达到生物脱氮除磷目的。     

难处理金矿的生物预氧化技术及工业应用

阐述了难处理金矿的含义及难处理原因 ,介绍了生物氧化提金的主要浸矿菌种和典型工艺 ,总结了生物氧化技术的特点 ,并对难处理金矿生物预氧化的研究工作提出了几点建议     

生物接触氧化法处理城镇污水技术经济分析

对生物接触氧化法处理城镇污水的工艺特点进行了分析 ,并通过与生物吸附法曝气池的技术经济对比分析 ,明确生物接触氧化法在城镇污水具有投资少、运行简便、处理效果好的优势     

难浸金矿预处理技术及其应用

本文综述了一些比较典型的难浸金矿的预处理技术及其工艺方法。预处理方法主要有焙烧预处理、生物氧化预处理、富氧或加助浸剂预处理、碱浸预处理、微波加热预处理等。难处理金矿将成为我国黄金工业发展的主要资源，因此难浸金矿的处理及预处理技术的开发与研究是当前我国黄金工业提金的关建。     

硫化镍矿生物浸出研究进展

微生物浸出技术是处理低品位硫化镍矿的有效方法之一。硫化镍矿生物浸出技术的研究对象主要包括浸矿菌、浸出机理、浸出工艺及影响因素等。介绍了硫化镍矿生物浸出常用菌种以及近年来开发的高效浸矿菌;论述了硫化镍矿生物浸出作用机制,即硫化镍矿微生物浸出是在直接和间接共同作用下被氧化溶解,同时也存在“原电池效应”引起的电化学氧化作用,在此基础上综述了硫化镍矿生物浸出机理的研究进展;总结了培养基、矿浆温度、矿浆pH值、矿浆浓度、表面活性剂等因素对低品位硫化镍矿生物浸出的影响;指出今后应从细菌培育、微生物代谢、浸出强化技术以及工艺条件优化等方面开展低品位硫化镍矿生物浸出技术研究。     

Research and application of bioleaching and biooxidation technologies in China

This paper presents some of the investigations of bioleaching and biooxidation applications in China. Bioleaching and biooxidation are new technologies with great potentials due to their simplicity, low operating cost, and little pollution to the environment. To date, two heap bioleaching plants and two biooxidation plants have been successfully put into operation to process copper ores and refractory gold concentrates, respectively. Investigations of applying bioleaching and biooxidation for other metal and non-metal resources are now being carried out.     

含砷金矿微生物预氧化过程强化方法研究进展

微生物预氧化技术具有成本低、设备简单、环境友好等优点,在难处理金矿资源的开发利用中得到了巨大发展和广泛认可。然而,由于原料来源复杂、浸矿菌种耐砷性差、浸矿过程容易生成钝化产物等问题,微生物预氧化在实际生产中依然受到一定程度的制约。目前如何强化含砷金矿微生物浸出已成为该领域的研究热点和难点。综述了目前国内外含砷金矿微生物预氧化强化方法的研究现状,其中详细阐述了应用氧化剂、金属离子、原电池效应、表面活性剂、腐殖酸和磁化水等强化方法的研究进展及作用机理。在此基础上,展望了该领域未来研究的主要发展方向,为含砷金矿微生物预氧化工艺的进一步开发及应用提供参考。      

Precipitation of valuable metals from bioleaching solution by biogenic sulfides

The aim of this work was to explore the possibility of using sulfate-reducing bacteria for the retrieval of valuable metals from a bioleaching solution. Tests were conducted to determine whether the bacteria produced hydrogen sulfide that could be used to precipitate valuable metals from a bioleaching solution as sulfides. The approach consisted of continuous culture of sulfate-reducing bacteria to produce hydrogen sulfide in the first reactor and the subsequent metal precipitation in the second reactor. Batch and continuous experiments were carried out to determine the optimum process parameters. The advantage of this process was demonstrated including faster precipitation of valuable metals and the possibility of the metal precipitation in the form of sulfides. A new flow sheet for the separation of Ni and Cu by biogenic sulfide precipitation in the presence of magnesium was proposed.     

金川低品位镍矿资源微生物浸出研究

金川低品位镍矿资源———贫矿和尾矿具有良好的生物可浸性 ,尾矿比贫矿更容易浸出。采用以氧化亚铁硫杆菌为主的混合浸矿菌株浸出金川尾矿 ,镍、铜、钴浸出率分别可达 87 84%、84 0 5 %和86 35 % ;贫矿细菌浸出 ,镍、铜、钴的浸出率分别达到 88 78%、47 68%和 65 65 %。针对金川矿石碱性脉石多 ,导致普通T·f菌浸出过程中耗酸量大、pH值不稳的特点 ,采用诱变技术选育了耐高pH值的浸矿菌株。该菌株应用于金川尾矿和贫矿浸出 ,浸出指标接近普通T·f菌浸出指标 ,为金川低品位资源生物浸出工业化应用奠定了良好的基础     

氧化亚铁硫杆菌对雄处理金矿石中常见硫化物单矿物的氧化

通过对难处理金矿石中各种硫化物单矿物进行的细菌氧化试验，发现在相同的条件下，硫化物晶体显微形貌变化、氧化腐蚀的时间截然不同。黄铁矿是最难氧化的硫化物矿物。黄铁矿细菌氧化全过程可分三个阶段，各阶段的黄铁矿显示不同的显微特征。黄铜矿是比较难于细菌氧化的矿物。除了毒砂之外，闪锌矿是易于细菌氧化的矿物，其它分别为铅矿、黝铜矿、辉锑矿。     

Use of mesalime and electric arc furnace (EAF) dust as neutralising agents in biooxidation and their effects on gold recovery in subsequent cyanidation

The cost of lime/limestone for neutralisation is the second largest operating cost in bioleaching. Therefore, these studies have been conducted with the aim to investigate the possibilities for use of by-products such as mesalime and electric arc furnace (EAF) dust for neutralisation during biooxidation of a refractory gold concentrate. Experiments were carried out using a retention time of 57 h in a one-stage reactor and the influence of two industrial by-products on the biooxidation performance was evaluated. The neutralising capacity of EAF dust was lower, while the mesalime was similar to the Ca(OH)₂ reference. The arsenopyrite oxidation in experiments ranged from 85% to 90%, whereas the pyrite oxidation was 63–74%. In subsequent cyanidation, final gold recoveries of 90% were achieved in bioresidues from mesalime and Ca(OH)₂, while the EAF dust bioresidue had a recovery of 85%. A comparatively high elemental sulphur content in EAF dust probably encapsulates part of the gold, which explains the lower recovery for the EAF dust bioresidue despite a longer residence time. Cyanide consumption was relatively high and ranged from 8.1 to 9.2 kg/ton feed after 24 h of cyanidation. Overall, the by-products tested here have proved to be feasible options as neutralising agents in bioleaching operations.     

Effects of dissolved oxygen and carbon dioxide under oxygen-rich conditions on the biooxidation process of refractory gold concentrate and the microbial community

Biomining microorganisms obtain energy from the oxidation of reduced sulfur and iron (II) by using dissolved oxygen (DO) as the electron acceptor. Carbon dioxide, the carbon source for biomining microorganisms, is essential for biooxidation. However, to date, no published reports exist regarding the effect of reactive oxygen species (ROS) and the CO₂ content in an oxygen-rich condition (when oxygen is sufficient) on the biooxidation process. In this study, a microbial community was used to oxidize refractory sulfide gold concentrate in a 1.5 L experimental stirred tank reactor. The effects of DO in a slurry and the CO₂ content in the intake gas on the biooxidation process, bacterial growth and microbial community were investigated. It was found that the biooxidation efficiency increased at first and then decreased as the DO level elevated, while the content of ROS significantly increased within the bacteria cells. Under an oxygen-rich condition, the biomass increased as the CO₂ content increased, while the biooxidation efficiency first increased and then decreased. These changes revealed that the oxidation activity of biomining microorganisms was inhibited by a high CO₂ content and that bacterial growth and energy utilization were decoupled. Leptospirillum ferriphilum-like bacteria and Sulfobacillus thermosulfidooxidans were the dominate strains in the experiment. As the DO increased, the relative proportion of L. ferriphilum-like bacteria in the bacteria community first increased and then decreased, while S. thermosulfidooxidans showed the opposite trend. With an increasing CO₂ content in the intake gas, the relative proportion of S. thermosulfidooxidans increased, while that of L. ferriphilum-like bacteria decreased.     

Bioleaching nickel laterite ores using multi-metal tolerant Aspergillus foetidus organism

Immediate environmental conditions expose the fungi organisms to a multitude of stresses in an in situ bio-leaching process. The most significant abiotic stress is from heavy metals which are dissolved by the metabolic products of the organism. Heavy metal stress can stimulate changes in the fungi metabolism which could inactivate its cellular functions critical in maintaining bio-acid production and leaching of minerals. Gradual acclimatization of the organism to increasing concentration of single metals forms the main method of adapting strains for this process. However in a bioleaching process, several metals are dissolved which exposes the organism to various levels of cation toxicity. In this study Aspergillus foetidus was trained using multi metal (Al, Co, Cr, Cu, Fe, Mg, Mn, Ni and Zn) environment to mimic a leaching system. The effect of the metal stress on the fungi metabolism was examined. Bioleaching of weathered saprolite ore using the heavy metal tolerant organism was assessed.     

硫化矿高温生物浸出工艺研究和应用进展

高温菌浸矿不仅比中温菌有更快的反应速率,而且还能有效浸出部分难溶原生硫化矿如黄铜矿等。因此,高温生物冶金工艺在湿法冶金中占据越来越重要的位置。对国内外高温菌浸矿的研究进展进行了综述,详细介绍了高温生物冶金工艺在提取金、铜、锌3种金属方面的应用,最后就如何发展和推广高温生物浸矿工艺提出了自己的一些看法。