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。     

细菌的氧化生理与其浸矿机理研究

对不同氧化生理的诱导菌、S^2-氧化缺陷型菌株和Fe^2 氧化活性抑制菌进行了黄铜矿浸出研究，表明黄铜矿的细菌浸出以氧化其S^2-的直接作用为主。     

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。     

上位直接顶“散体拱”结构的形成及失稳演化

通过相似模拟实验和理论分析,研究了综放条件下上位直接顶“散体拱”结构的形成机理和移动演化过程.认为在综放条件下,以散体状态出现的直接顶岩块在渐进流动过程中的某一时刻,由流动孔口周边作用的垂直剪切力与上方垮落岩体重力之间形成的应力平衡是上位直接顶“散体拱”结构形成的力学条件;工作面的不断推进及“散体拱”结构的不对称性而导致的承载能力不均,造成后拱脚和前拱脚先后失稳是“散体拱”结构不断失稳、重组和前移的原因.     

黄铜矿的细菌氧化

研究了氧化亚铁硫杆菌对黄铜矿的浸出行为。在酸性介质中，黄铜矿被氧化成CuSO4和Fe2（SO4）3。加入0．4％的FeSO4·7H2O，加快了黄铜矿的最初浸出速率，更高的Fe2 浓度反而抑制最初浸出速率。加入Fe2（SO4）3使浸出速率增加。加入Fe2 和Fe3 使最终浸出率达到78．7％，而仅用细菌浸出的最终浸出率只有69％。通过研究细胞质酶对S2-的氧化，发现细胞色素C参与了S2-的氧化，从而间接证明了细菌对黄铜矿的直接作用。     

细菌浸矿的间接作用分析

总结细菌浸矿间接作用的研究成果，阐述细菌浸出过程间接作用的观点，从细菌间接作用角度较系统地分析细菌间接作用过程机理，说明问接作用过程的基本步骤。根据硫化矿物晶体结构不同。间接作用过程中，硫化矿的氯化分解有以S2O3^2-为中间过程和以Sn^2-与S8为中间过程的两种氧化机理。     

氯化银对黄铜矿精矿生物浸出的影响

日本用氧化亚铁硫杆菌 (Ｔｈｉｏｂａｃｉｌｌｕｓｆｅｒｒｏｏｘｉｄａｎｓ)研究了加入氯化银对含有黄铁矿、闪锌矿和方铅矿硫化矿物的黄铜矿精矿生物浸出的影响。加入氯化银加速黄铜矿精矿中铜的溶解。用氯化银比生物浸出开始步骤加入硫酸银溶液铜的溶解速率更大。银的回收率随ＡｇＣｌ的数量的增多而加快。没有ＡｇＣｌ与黄铜矿之间的接触 ,就不会强化黄铜矿的溶解。氯化银对黄铜矿精矿生物浸出的影响@许孙曲     

低品位矿石微生物浸出作用机理研究

微生物种类及其作用机理是浸出低品位矿石的关键所在。将浸矿细菌分为中温菌、中等嗜热菌和高温菌三类,分别对其生长环境、外部形态特征和浸矿特性进行了系统、深入的研究,为浸矿菌种的选择提供依据。微生物作用机理至今还存在很大争议,普遍的观点认为主要有三种作用机理:直接作用、间接作用和直接———间接复合作用,本文将浸出体系中的细菌分为游离细菌和吸附细菌,提出了间接———接触间接———直接复合作用机理,并分析了各种情况下的主要作用机理。     

黄铜矿生物浸出的钝化机制及强化浸出方法

生物浸出技术(也称生物湿法冶金技术)多应用于常规方法难以开发利用的尾矿、贫矿、废矿、表外矿及 难采、难选和难冶矿,其工业应用从 20 世纪逐步开始发展,现已在国内具备相当的规模,目前对辉铜矿的原矿处理已 实现了工业化应用。 相较于传统的铜冶炼技术,生物浸出技术具有流程简单、生产成本较低等优势。 主要阐述了黄铜 矿在生物浸出反应过程中钝化膜的形成机制,介绍了黄铜矿表面钝化膜组成成分的几种主流观点,主要包括氢氧化 铁和黄钾铁矾、单质硫、铜的聚硫化物等;并针对钝化作用所导致的浸出反应缓慢、浸出率低等生物浸出普遍面临的 问题,从高效浸矿细菌的选育、各类药剂的催化等方面列举出了学者们在强化黄铜矿生物浸出的研究方面所做出的 有益探索,虽然提出的以上方法在工业应用上目前还不具备成熟的条件,但对今后黄铜矿生物浸出工艺的发展和改 进具有参考和指导意义。     

黄铜矿半导体电学特性对其中等嗜热菌浸出行为的影响

为了研究黄铜矿半导体电学特性对其生物浸出的影响机制, 采用霍尔效应测试技术分析了3种不同来源黄铜矿的半导体电学特性, 并在45 ℃、170 r/min、2%矿浆浓度条件下进行了中等嗜热混合菌浸出试验。结果表明, 黄铜矿A的载流子浓度为-9.190×10¹⁸ cm^-3, 绝对值明显高于黄铜矿B和C的载流子浓度(-3.065×10¹⁸ cm^-3和-2.183×10¹⁷ cm^-3); 黄铜矿A的电阻率为0.054 65 Ω·cm, 明显低于黄铜矿B和C的电阻率(0.146 9 Ω·cm和0.930 6 Ω·cm); 黄铜矿的载流子浓度、电阻率与其铜浸出率存在明显联系, 黄铜矿的载流子浓度越高、电阻率越小, 铜的浸出速率就越高, 浸出19 d后, 3种黄铜矿纯矿物(A、B、C)的铜浸出率分别为66.1%, 25.3%和21.4%; 电化学试验结果表明, 3种黄铜矿的氧化还原反应过程基本相同, 但黄铜矿A的腐蚀电流密度明显高于另外两者。     

Cooperative effect of chalcopyrite and bornite interactions during bioleaching by mixed moderately thermophilic culture

The cooperative interactions between chalcopyrite and bornite during bioleaching by mixed moderately thermophilic culture were investigated mainly by bioleaching experiments and electrochemical experiments. Bioleaching results showed that a cooperative effect existed between chalcopyrite and bornite. When the mass ratio of chalcopyrite to bornite was 3:1, an extremely high copper extraction of more than 88% was achieved after bioleaching for 27 days. One of the major reasons for the cooperative effect was that a certain redox potential range (370–450 mV vs. Ag/AgCl) could be maintained for a long period of time during bioleaching due to the mixture of chalcopyrite and bornite. Electrochemical measurements revealed that chalcopyrite was much easier to be reduced than oxidized, while bornite was prone to be directly oxidized. Hence, galvanic effect between chalcopyrite and bornite enhanced the reduction of chalcopyrite to secondary copper-iron species and promoted the oxidative dissolution of bornite. Therefore, redox potential controlling and galvanic effect both contributed to the cooperative bioleaching of chalcopyrite and bornite.     

The effect of redox control on the continuous bioleaching of chalcopyrite concentrate

A continuous bioleaching process was developed for the dissolution of chalcopyrite concentrate with electrochemically redox control. Therefore, using a flotation concentrate containing 46% chalcopyrite and 23% pyrite, bioleaching tests were carried out at 47 °C with 15% pulp density under controlled and uncontrolled redox conditions. To increase the copper recovery in contrast to the conventional bioleaching (∼39.62%), the effect of redox potential on the chalcopyrite bioleaching was investigated by electrochemically controlled bioleaching. The results showed that by controlling the redox potential, faster copper leach kinetics could be achieved. At last, reducing the redox potential from high levels to optimum window (420–440 mV SCE) caused an increase in copper recovery from around 39% to higher than 69% (over 25 g/L Cu²⁺).     

矿物学因素对黄铜矿微生物浸出影响的研究现状

黄铜矿微生物浸出一直是近年来的研究热点,研究者们主要从化学、矿物学及生物化学等角度展开对黄铜矿与细菌相互作用的研究。本文综述了影响黄铜矿微生物浸出的矿物学因素方面的研究,指出晶格能、晶格缺陷和同质多像等是影响微生物浸出黄铜矿的重要因素,并对未来的研究趋势进行了展望,这对日后黄铜矿微生物浸出工作的发展具有重要的意义。     

Electrochemical dissolution process of chalcopyrite in the presence of mesophilic microorganisms

The dissolution process of chalcopyrite in the presence of mesophilic microorganisms was investigated by electrochemical measurements. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis, accompanied by leaching experiments. Results proved that the presence of Acidithiobacillus ferrooxidans enhanced the initial reduction of chalcopyrite to intermediate species (Cu₂S), thus promoting the dissolution of chalcopyrite in the initial stage of bioleaching. However, chalcopyrite tended to be directly oxidized to polysulfide (S_n²⁻) and CuS in the later stage of bioleaching when redox potential was higher than 0.5 V (vs. Ag/AgCl), the formed polysulfide and jarosite can be responsible for the passivation of chalcopyrite in the later stage of bioleaching by A. ferrooxidans. On the contrary, Chalcopyrite was mainly directly oxidized to polysulfide and CuS in the presence of sterile 9K medium or Acidithiobacillus thiooxidans, and the initial reduction reaction was still the rate-limiting step, thus resulting in low copper extraction rate.     

中温及嗜热菌对不同成因黄铜矿浸出行为的影响

以斑岩型黄铜矿和矽卡岩型黄铜矿为研究对象,考察了嗜酸氧化亚铁微螺菌(L f)和嗜热硫氧化硫化杆菌(S t)对不同成因黄铜矿浸出行为的影响。结果表明,在2种不同细菌浸出体系中矽卡岩型黄铜矿均表现出比斑岩型黄铜矿浸出率高;S t浸出2种不同成因黄铜矿的效率均比L f的好。通过对不同浸矿时间黄铜矿浸出渣的XRD检测并结合黄铜矿浸出过程反应步骤的分析表明,2种细菌浸出不同成因黄铜矿的机制相同,细菌的代谢途径及反应温度是影响同类成因黄铜矿浸出率和代谢产物差异的主要原因。S t作用下浸出后期黄铜矿表面有黄钾铁矾生成,而L f浸出体系黄铜矿表面主要是S的不断积累。同种浸矿菌种浸出不同成因黄铜矿时,矽卡岩型黄铜矿在浸出第15 d有S生成,斑岩型黄铜矿在S t浸出体系S生成的时间更晚,在L f浸出体系S的生成量则更少,推测矿物性质是引起其差异的主要原因。     

Cooperative bioleaching of chalcopyrite and silver-bearing tailing by mixed moderately thermophilic culture: An emphasis on the chalcopyrite dissolution with XPS and electrochemical analysis

In this work, the interactions between one sample of silver-bearing tailing (223 g/t silver) and chalcopyrite during bioleaching by mixed moderately thermophilic culture were investigated. Bioleaching results showed that copper can be almost totally extracted from chalcopyrite as the result of addition of the silver-bearing tailing, and silver (Ag) extraction can be significantly improved with the addition of chalcopyrite. Hence, cooperative bioleaching process of chalcopyrite and the chosen silver-bearing tailing was feasible. Ag mainly occurred as silver sulfate (Ag₂SO₄), and further work of enhancing the Ag extraction and its recovery is currently in progress. The catalytic effect of the silver-bearing tailing on chalcopyrite dissolution was investigated mainly with X-ray photoelectron spectroscopy (XPS) and electrochemical analysis. Results proved that the presence of the silver-bearing tailing enhanced the oxidation rate of chalcopyrite and also eliminated the passivation effect of polysulfide, thus resulting in an extremely high copper extraction.     

中等嗜热菌浸出德兴黄铜矿的试验研究

对中等嗜热菌在45 ℃下浸出德兴黄铜矿的情况进行了试验研究。结果表明,添加适量（4 g/L）的Fe²⁺有利于中等嗜热菌的生长和黄铜矿的浸出;中等嗜热菌活性高有利于提高黄铜矿的浸出率;在试验酸度范围内,pH=1.50时中等嗜热菌的活性最高;矿浆浓度越低、粒度越细,越有利黄铜矿的浸出。在最佳试验条件下,黄铜矿49.2 d的铜浸出率为73.32%。浸出渣的XRD分析结果揭示,在浸出一段时间后,黄铜矿慢慢发生钝化的原因在于硫单质和黄钾铁矾在其表面的附着。     

黄铜矿细菌浸出机理及钝化原因研究进展

细菌冶金技术由于成本低、污染少、流程短等优点,越来越受到人们重视,由于在常温下黄铜矿的细菌浸出速率较慢,有必要研究提高黄铜矿浸出速率的方法。综述了黄铜矿的细菌浸出机理以及黄铜矿的钝化原因。研究结果表明黄钾铁矾、硫层、中间产物层、高的溶液还原电位和黄铜矿稳定的晶体结构可能是黄铜矿细菌浸出过程中的钝化原因。