【作者】 贾春云；

【导师】 魏德洲；

【作者基本信息】 东北大学 ， 矿物加工工程， 2008， 博士

【摘要】 随着矿产资源的不断开发利用,以贫、细、杂为突出特点的难处理矿石所占的比例不断上升,致使矿物加工领域面临的挑战日趋严峻,而且较多药剂的使用还会污染环境。在此背景下应运而生的资源微生物技术为解决矿产资源领域中所存在的问题提供了新途径。资源微生物技术经历了近40年的发展,无论在基础研究还是实际应用方面都取得了令人瞩目的成就。已进行的关于微生物在矿物表面吸附的研究,大多数是为了探讨生物湿法冶金过程中的作用机制而进行的,研究的主要内容是影响细菌吸附量的因素、细菌吸附量与浸出效果的关系以及发生吸附后的宏观效果；已进行的一些关于选择性吸附的研究工作,进行的深度非常有限,主要是通过控制吸附条件,有目的地强化选择性吸附现象,对发生选择性吸附的机理只进行了初步分析。本文研究了微生物细胞在硫化物矿物表面的选择性吸附现象,并借助先进的检测方法探讨了微生物发生选择性吸附的原因,主要研究工作总结为以下几个方面：1、进行了微生物的形态与性质研究,对氧化亚铁硫杆菌、沟戈登氏菌、草分枝杆菌、胶质芽孢杆菌的培养性状、染色特征和扫描电子显微镜形貌进行了观察,并对4种微生物的物理化学特性进行了分析,测定了它们的表面主要元素含量、表面化学组成、分子量、生长曲线、接触角、荷电特性等。2、研究了不同影响因素下4种微生物在黄铁矿、黄铜矿、方铅矿和闪锌矿表面的吸附规律,结果表明氧化亚铁硫杆菌在硫化物矿物表面的吸附无明显选择性；沟戈登氏菌、草分枝杆菌、胶质芽孢杆菌在4种硫化物矿物表面的吸附均具有明显的选择性,而且在黄铁矿表面的吸附率远远大于其他3种硫化物矿物,吸附体系的pH值是影响细菌在矿物表面发生选择性吸附的关键因素。3、选择氧化亚铁硫杆菌和草分枝杆菌作为研究对象,通过红外光谱和X射线光电子能谱深入的研究了在硫化物矿物表面有无明显选择性吸附的微生物细胞表面的功能基团,初步确定了细胞表面诱发选择性吸附的可能基团。4、应用矿物晶体化学原理分析了4种硫化物矿物破碎后的表面结构和性质,并用X射线光电子能谱分析了矿物表面各元素的状态,初步推断矿物表面诱发微生物发生选择性的主要元素及其价态。5、通过扫描电镜、红外光谱和X射线光电子能谱研究了与氧化亚铁硫杆菌和草分枝杆菌作用后硫化物矿物的表面特征及其表面元素状态的变化。结果验证了这两种细菌在矿物表面的吸附现象,并得出两种细胞表面的O-H或N-H、C-O等有机基团通过矿物表面的Fe、Cu、Pb、Zn、S元素与矿物表面发生了化学吸附,且与矿物表面金属元素的作用程度大于硫元素。6、通过分析微生物在硫化物矿物表面的选择性吸附现象,发现细胞表面的特征基团对黄铁矿表面金属离子的亲和力大于其他3种硫化物矿物,Fe3+起到了比较重要的作用,另外,两类细菌的表面特征及其生理特点也对细胞的选择性吸附程度大小有一定的影响。7、研究了氧化亚铁硫杆菌和草分枝杆菌预处理后4种硫化物矿物的可浮性。结果表明,经两种细菌预处理后4种矿物的可浮性均有所下降,但是经草分枝杆菌预处理后黄铁矿几乎完全被抑制。更多还原

【Abstract】 Along with the continuous exploitation and utilization of mineral resource, the proportion of unwieldiness ores with deficient, poor and complicated character is rising day and day. As a result, the mineral processing fields face serious challenge, and using more medicaments will pollute environment. Under these circumstances, microbial technology to resources emerges as the times require, which provides a new way to solve the problem of mineral resources utilization. After developing for nearly forty years, microbial technology to resources has gained great achievement in basal research and practical application.Much work having been carried out focus on discussing interaction mechanism in the process of microbiohydrometallurgy, and the main content are factors influencing the adsorbing biomass, the relationship of the adsorbing biomass and bioleaching effect, the macroscopic effect after interacted with microbe. The research about selective adsorption is not deep, which is mainly to intensify selective adsorption phenomena by controlling adsorption conditions and the selective adsorption mechanism is analyzed primarily. In this thesis, the selective adsorption of bacteria on sulfide mineral surface is studied and the key factor resulting selective adsorption is founded by some advanced detection methods. The work in the present paper can be summarized as follows:1. The morphlogy and characteristic of bacteria were investigated. Four strains of bacteria were used:Thiobacillus ferrooxidans, Gordona amarae, Mycobacterium phlei and Bacillus mucilayinosus. Their microscopys were displaied, the physical chemistry charaterisritic of four strains of bacteria were inspected. Measure and test in the cell surface characterization including surface elements’ content, UVS spectroscopy, molecular weight, growth curve, contact angle and Zeta-potential.2. Adsorption of four strains of bacteria on the surface of pyrite, chalcopyrite, galena and sphalerite were studied under different influence factors. The results showed that the selective adsorption of Thiobacillus ferrooxidans on sulfide minerals is not obvious, and that of other three strains of bacteria is obvious, more cells absorbed on pyrite and less cells absorbed on chalcopyrite, galena and sphalerite, pH is the key factor influencing selective adsorption of bacteria on mineral surface.3. Choose Thiobacillus ferrooxidans and Mycobacterium phlei as study objects, the functional groups on the surface of bacteria which having a selective adsorption or not were investigated by FTIR and XPS, and the groups inducing selective adsorption are ensured primarily.4. The surface structure and character of four sulfide minerals after cleavage is analyzed by the principle of mineral crystal chemistry, and the state of every element on mineral surface is analyzed by XPS, it is concluded primarily that the main element and its valency on mineral surface which inducing bacteria to have a selective adsorption.5. The mineral surface characteristic of sulfide minerals after interaction with Thiobacillus ferrooxidans and Mycobacterium phlei were achieved by SEM, and the state change of each element on mineral surface were studied by FTIR and XPS. The results are in agreement with adsorption phenomena of these two strains of bacteria on sulfide minerals. It is drawn that the O—H or N—H and C=O groups on two strains’ cells have a chemisorption to element Fe, Cu, Pb, Zn, S on mineral surface, and the action of these groups to metal ions on mineral surface is stronger than that of elment S.6. The selective adsorption phenomena of bacteria on sulfide minerals are analyzed. It is discovered that the affinity of functional groups on cell surface to metal ion on pyrite surface is large than that of other three sulfide minerals, and Fe3+ is more important in it. In addition, the surface character and physical characteristic of two kinds of bacteria also have an influence on cells’selective adsorption7. The flotation of four sulfide minerals after pretreated by Thiobacillus ferrooxidans and Mycobacterium phlei were studied. The results indicate the flotation of four sulfide minerals all descend after pretreatment, and pyrite is almost depressed completely after pretreated by Mycobacterium phlei.更多还原