硅酸盐细菌生长及对硅酸盐矿物中硅铝的浸溶

为了找到能从高硅含量的硅酸盐矿物中脱硅的细菌,利用常规微生物筛选技术,从硅酸盐肥料中筛选到1株编号为JXF菌株,通过形态学研究,并与标准的胶质芽孢杆菌等硅酸盐细菌的生化特征比较,表明JXF细菌为胶质芽孢杆菌。摇瓶浸矿试验表明,硅酸盐细菌具有较强的活化、吸持硅酸盐矿物中硅、铝的能力,以高岭石为底物,培养2~6d,接灭活菌上清液中硅的含量均高于接菌组中硅的含量,细菌吸持的硅含量占解硅量的90%左右,细菌数越多,细胞吸持的硅也多。通过对浸渣主要矿物物相分析,表明层状结构的硅酸盐矿物如高岭石、伊利石等较易被细菌作用而释放出其中的硅、铝、钾等元素。     

矿物结构对胶质芽孢杆菌生长代谢及溶硅的影响

选用一株胶质芽孢杆菌,通过检测发酵培养液中代谢产物种类与含量、SiO2浓度、pH值、细菌数量以及分析胶质芽孢杆菌-矿物相互作用后矿物表面微观形态与结构的变化,研究该菌种在高岭土、石英与铝土矿环境中生长代谢规律及对不同矿物的分解作用机制.结果表明,该菌种在不同矿物环境中生长规律基本一致,生长周期有一定差异;铝硅酸盐矿物能显著促进与刺激该菌种生长代谢能力,其中高岭土对菌种作用最为明显;该菌种对高岭土分解效果最好,发酵15d后,浸出液中SiO2质量浓度达到41 mg/L左右;高岭土与铝土矿表面微观形态与石英相比变化明显,表明矿物结构是影响硅酸盐矿物微生物分解的重要因素.     

利用硅酸盐细菌制备煤矸石矿物肥料

针对大量堆弃煤矸石造成的严重环境问题,研究胶质芽孢杆菌和多粘类芽孢杆菌作用于难以被植物利用的硅酸盐矿物,将其转化为煤矸石矿物肥料,并研究了堆肥过程中的固液比、堆肥时间、环境温度、硅酸盐细菌混合比例等因素对煤矸石矿物肥料品质的影响。研究表明,当采用混合菌悬液1∶1,控制固液比1∶1(湿润),25°C下堆肥15 d时,矿物肥料中的有效磷含量和速效钾含量较高,是原煤矸石样品中含量的5.12倍和2.01倍。     

微生物矿物源土壤修复剂配施效果的研究

以白刺为试验对象,考察了白云鄂博富钾板岩发酵产物与胶质芽孢杆菌复合制备出的微生物矿物源土壤修复剂性能及其二者施用量的最优配比。结果表明,通过对不同配比处理下种植的白刺生物学性状及土壤理化性质的分析,发现两种原料添加的最优配比为土壤与固体发酵产物添加比30∶1,菌液添加量为2.5L/m2。此配比下白刺的发芽率、茎长和干鲜重指标达到空白处理的2.40、4.35、12.35倍,土壤的含水率、有机质、有效磷和速效钾含量分别提高了10.36、1.30、5.54、1.10倍,均达到显著水平(p<0.05)。加入胶质芽孢杆菌菌液后土壤中的稀土元素总量降低了74.88mg/kg。可以合理有效地利用白云鄂博富钾板岩,对尾矿库周边环境治理和污染土壤的修复改良具有重要意义。     

胶质芽孢杆菌对水中Pb2+生物吸附-浮选性能研究

用胶质芽孢杆菌作吸附剂,探讨了采用生物吸附-浮选法去除水相中Pb2 的可能性,并对生物吸附机理和吸附剂与捕收剂的作用机理进行了分析.结果表明,用阳离子型捕收剂对胶质芽孢杆菌有较高的去除率,在pH为3～6的范围内,用十二胺浮选吸附了Pb2 的胶质芽孢杆菌,可获得较好的菌细胞和Pb2 的去除效果.在浮选pH=6.25、十二胺用量为0.375 mol/L时,菌细胞和Pb2 的去除率均达到了98%以上.选用Na2CO3作为解吸剂,浓度为1.2 mol/L、pH=4.75时,对吸附Pb2 后的胶质芽孢杆菌的解吸效果可以达到100%.动电位测试和红外光谱分析结果表明,胶质芽孢杆菌的自然等电点为2.39,吸附Pb2 后变为2.83,菌细胞与Pb2 的吸附过程主要与细胞多糖成分有关,吸附过程主要是静电吸引;吸附了Pb2 的菌细胞用十二胺浮选后等电点增至2.94,十二胺对菌细胞的浮选与细胞表面的酰胺基团和缔合-OH有关,吸附过程中有静电力、氢键和范德华力参与.     

矿物微生物诱导浮选和絮凝

矿物与微生物作用会使矿物的表面化学性质发生很大变化。例如，矿质化学营养细菌(氧化亚铁硫杆菌和硫氧化硫杆菌)可使黄铁矿、黄铜矿、闪锌矿和方铅矿等硫化矿物表面化学性质发生很大变化。杆菌类异养细菌可以改变赤铁矿、氧化铝、二氧化硅、高岭石和方解石等氧化矿物的动电性质。微生物与矿物之间的作用通过选择性生物浸出已用于选矿中。与生物浸出法不同。细菌诱导选矿法涉及到矿物一溶液一细菌界面之问的表面现象，并且在该过程中，表面化学变化在几分钟之内在水介质中发生。在本文中说明了嗜酸的矿质化学营养细菌(硫氧化硫杆菌)和嗜中性的异养细菌(多黏芽胞杆菌)在氧化矿物和硫化矿物选矿中的作用。从细菌作用对矿物表面疏水性和亲水性影响出发，概述了细菌在氧化矿物和硫化矿物上的附着机理。讨论了细菌细胞及其代谢物(生物蛋白质和外多糖)对硫化矿物(闪锌矿和方铅矿)及氧化矿物(赤铁矿、氧化铝和方解石)表面性质改变中的作用。在细菌对矿物基质驯服以后，可以得到对矿物具有特效性的生物药剂。     

黏土矿物对土壤中重金属的钝化作用研究进展

为了助推我国重金属污染土壤的修复与治理,促进我国环保工作者熟悉黏土矿物在土壤重金属污染治理与修复中的重要作用和技术进展情况,对土壤重金属污染修复技术以及天然黏土矿物对土壤中重金属的钝化作用效果进行总结,提出了黏土矿物作为环境功能材料在土壤重金属修复领域的优势,重点阐述了黏土矿物的改性方法及改性机理,包括物理改性、化学改性、复合改性等,并总结了改性黏土矿物材料对土壤中重金属钝化性能的提升和钝化机理,综合分析了黏土矿物作为环境功能材料的优缺点。最后,结合目前该领域的研究与实践情况,针对改性黏土矿物材料的研究和应用前景进行了展望,提出长效考察、联合修复、土壤分类、移除技术及基于矿物相组成差异的修复等是今后研究的重要方向。     

Alicyclobacillus属细菌及其在生物冶金中的研究进展

脂环酸芽孢杆菌(Alicyclobacillus)属细菌广泛存在于酸性果汁饮料、矿山、热泉和火山附近土壤等酸热环境中,具有嗜酸耐热的典型特征。多项研究表明该属细菌具有广泛的底物利用特性,可以利用有机物进行异养生长,也可以氧化Fe2+、元素硫以及硫化矿等进行自养生长,在厌氧或微缺氧的条件下还可以还原Fe3+以及针铁矿等铁的沉淀物中的Fe?,因此该属细菌在生物冶金中具有巨大应用潜力,而目前关于该属细菌在生物冶金中的研究报道很少。对Alicyclobacillus属细菌的分离、生理生化特征以及在生物冶金领域中的国内外研究现状进行概述和分析,并展望了未来该属细菌在生物冶金领域中的研究方向。     

细菌氧化对黄铁矿浮游性的影响

前言众所周知,目前正在研究象铁氧化硫杆菌、硫氧化硫杆菌等氧化铁和硫的细菌,在废水处理时氧化Fe~(2 )离子、细菌浸出、煤炭脱硫(硫化铁矿物的氧化及溶解)等方面的应用。而且也有栅原和松尾矿山利用细菌处理坑道废水和由低品位铜矿石中回收铜等已经应用到生产上的例子。这样,在与矿业有关的领域中应用细菌,与经济、技术乃至环境问     

矿物的微生物诱导浮选和絮凝:前景和挑战

最近已经了解到不同微生物在不同矿物表面化学性质变化中起着重要作用.例如,矿质化学营养细菌(如嗜酸的氧化亚铁硫杆菌和硫氧化硫杆菌)可急剧地改变一些硫化矿物(如黄铁矿、黄铜矿、闪锌矿、方铅矿和毒砂)的表面化学组成.异养细菌(如Paenibacillus polymaxy(多粘芽胞杆菌))也可改变氧化矿物(赤铁矿、氧化铝、二氧化硅、高岭石和方解石)的动电性质.在选矿(即选择性浮选和选择性絮凝)中应用矿物与细菌的相互作用是有好处的.与生物浸出不同,细菌诱导选矿借助矿物-溶液-细菌界面上快速发生的界面反应,这种作用是由在分离的水介质中的表面化学变化引起的.本文叙述了嗜酸的矿质化学细菌(如氧化亚铁硫杆菌和硫氧化硫杆菌)和嗜中性的异养细菌(如Paenibacillus polymaxy在硫化矿物和氧化矿物分选所起的作用.根据可能的机理讨论了细菌细胞和代谢产物(如生物蛋白质和外多糖)在改变矿物表面化学组成中所起的作用.还说明了在矿物分选中所用的生物药剂.概括了细菌诱导选矿的工业应用前景和未来的挑战.     

我国砂石土类矿产开发利用现状及建议

我国砂石土类矿产资源丰富,分布区域广泛,是我国开采总量最大的矿产资源。随着基础设施建设和房地产业开发的高速发展,砂石土类矿产的需求量也在持续增长,其带来的环境压力与政策的不适应性等问题逐渐凸显。通过统计砂石土类矿产近十年的年产量、矿山企业数、采矿权出让宗数等数据,对其开发利用管理情况进行分析,提出要以优化开采方式和资源循环利用的方法继续砂石土类矿产的开采,并基于政府职能的视角,提出政府应该把工作重心放在监管上,针对砂石土类矿产的特点以及不同地区的现实情况,制定相匹配的制度,使砂石土类矿产的发展规范化、系统化、绿色化。      

An investigation into electrochemical interactions between platinum group minerals and xanthate: Voltammetric study

In the flotation of platinum group minerals (PGMs) containing significant amounts of tellurides and arsenides it is generally assumed that these minerals will respond in the same way as sulphides to collectors such as xanthates which are typically used in sulphide flotation. This paper presents the results of a fundamental study which has been conducted to provide a greater insight into the comparative interactions between synthetic moncheite (PtTe₂) and cooperite (PtS) with sodium ethyl xanthate (SEX). Cyclic voltammetry has been used to investigate these interactions in the absence and presence of sodium ethyl xanthate (SEX) in aerated and de-aerated solutions. Reduction potentials of the SEX/dixanthogen couple have been measured and compared to published data. Reduction potentials of possible reactions of the minerals have been predicted from thermodynamic calculations and used to attempt to interpret the potentials measured in the cyclic voltammetry investigations. Results have shown differences in the oxidation behaviour of the minerals as well as in the SEX interaction with the minerals. The effect of pH was investigated in the case of the Pt minerals and fractional surface coverages were calculated with a view to ultimately correlate these results with flotation behaviour. Proposals are made with respect to the various reactions occurring under the conditions studied.     

天然矿物治理污染物研究进展与展望

天然矿物对污染物的净化功能主要体现在环境矿物材料基本性能方面。天然铁的硫化物、天然铁的氧化物、天然锰的氧化物、天然钛的氧化物、天然蛭石、有机蒙脱石和含高价阳离子蒙脱石以及黄钾铁矾等均在处理无机与有机污染物方面展现出良好效果。矿物与其环境界面原子尺度相互作用过程研究、矿物内部结构缺陷影响矿物表面活性规律研究，矿物晶体结构中不同维次连通性孔道效应研究、矿物化学活性作用净化污染物方法研究以及矿物晶芽与生物细胞层次上交互作用净化污染物机理研究等，将是近期着力开发无机界矿物天然自净化功能的重点研究内容。     

Potential Release of Metals from Tailings and Soil at the Hamekasi Iron Mine,Hamadan, Iran

This study focused on acid neutralization reactions and the effects of water composition on the release and mobility of metals from mine tailings. The aims of this study were to: investigate leaching of metals from neutral mine tailings, determine the factors responsible for metal leaching, and investigate potential metal filtering by the soil. Tailings and soil samples were collected from an iron mine and analyzed. Equilibrium thermodynamic data and metal fractionation were then used to predict precipitation/dissolution of minerals and ion adsorption/desorption. Three column experiments were designed. The first column was filled with tailings, while the second column contained tailings above a layer of soil; both were leached with distilled water as rainfall. The third column was packed with soil and percolated with synthetic groundwater. The results indicated that iron (Fe) and zinc (Zn) mobility are mainly controlled by precipitation–dissolution mechanisms, while sorption onto oxides and carbonates limit the mobility of copper (Cu) and nickel (Ni). Cadmium (Cd) and manganese (Mn) mobility are affected by both mechanisms. Water discharging from column 3 (soil washed with groundwater) contained high concentrations of dissolved metals, indicating that water composition played an important role in metal mobility. Buffering minerals like carbonates and hornblende, chlorite, and albite decreased acid generation.     

Understanding interaction mechanisms between pentlandite and gangue minerals by zeta potential and surface force measurements

Understanding the interaction between valuable and gangue minerals is of both fundamental and practical importance in the field of flotation. In this study, we investigated the interactions between valuable (i.e. pentlandite) and gangue minerals (i.e. serpentine, olivine, and magnesite) in an aqueous solution by directly measuring the zeta potential distributions. In addition, interaction force measurements using an atomic force microscope (AFM) were performed between a silicon nitride tip and gangue mineral surfaces, and the classical Derjaguin–Landau–Verwey–Overbeek (DLVO) theory was used to fit the interaction force between the silicon nitride tip and gangue mineral surfaces. In the case of serpentine and pentlandite mixture system at pH 10.1, only a single zeta potential distribution was obtained, as compared to two distinct distributions for the two individual minerals, indicating an attractive interaction is present between the two minerals. For olivine and pentlandite mixture system, a single distribution with two distinct spikes was obtained in the zeta potential distribution of the mixture, indicating repulsive interaction between the two minerals. Similarly, a single distribution with two distinct spikes was also observed in the zeta potential distribution of magnesite and pentlandite mixture system, indicating repulsive interaction between the two minerals. Repulsive interaction between silicon nitride tip and olivine surface, and slight attractive interaction between silicon nitride tip and magnesite surface, were observed and consistent with the DLVO model. The zeta potential and AFM force measurements show good agreement regarding the surface charge properties and interactions of the minerals, and provide complementary information and new insights into the interaction mechanism of valuable and gangue minerals.     

TOF-SIMS studies of surface chemistry of minerals subjected to flotation separation – A review

This paper reviews the applications of time of flight secondary ion mass spectrometry (TOF-SIMS) used for surface chemical analysis of mineral in the context of froth flotation. A wide range of applications are reviewed, including; interactions of reagents on the surface of mineral phases during flotation separation, determining the effects of various transferred ions from different minerals or the slurry, evaluation of hydrophobicity, identifying the relationship between mineral surface chemistry and contact angle, and evaluation of grinding effects. Conclusions indicated that TOF-SIMS, as a unique surface analysis technique, can potentially provide a direct determination of parameters which control the surface reactivity and consequently plays an important role in determining flotation behaviour of minerals.     

煤中稀土元素几个奇特的地球化学现象——以渭北中级煤为例

通过对渭北5号煤层中稀土元素含量和可溶有机质、灰分及REE的三价元素离子半径、能量系数、摩尔规定熵以及煤的Ro,Rmax/Rmin等重要参数的相关处理,推测REE在煤中矿物赋存形式可按三分法:LREE为被吸附于黏土的中性原子或+3价离子态,MREE为硫化物或碳酸盐结合态,而HREE则为含Sc+3等矿物的类质同像;在氯仿沥青"A"抽提实验中,LREE可以有机配合物形式少量出现在各个族组分中,这一结论对了解镜质组煤化学结构有着重要的意义;稀土元素对煤生烃的烃相对转化率的催化作用,温度为主导的煤变质作用、静压力对稀土元素的赋存形式的影响,以及它们之间的相互作用,均受稀土元素+3价离子半径大小的控制。这些交互作用,有可能使LREE在不同矿物之间有互相迁移的趋势。这些认识,也从稀土元素与它们各自的能量系数、摩尔规定熵等重要参数之间的关系那里得到印证。     

Mapping hydrophobicity combining AFM and Raman spectroscopy

A new concept to evaluate the floatability of individual minerals in an ore specimen is presented. The method is based on the combination of colloidal probe atomic force microscopy to determine hydrophobic interactions responsible for the flotation of fine mineral particles and Raman spectroscopy to identify the mineral phase at the same location. Both methods show a high spatial resolution and allow investigating even small individual minerals. The ore sample of this study is a syenite rock from south Sweden containing the valuable rare earth mineral eudialyte and gangue minerals mainly comprising feldspars, nepheline, aegirine and zeolites. Using the poor selective collector sodium oleate we demonstrate how hydrophobic interactions become apparent by conducting force distance measurements in the aqueous environment. We discuss different parameters of the force spectroscopy in static and dynamic mode to be used to define a measure for floatability. In contrast to other studies on the hydrophobic interactions in flotation we propose to draw information from the detachment of the hydrophobic probe particle of the atomic force microscope from the mineral surface in contrast to the approach force distance spectroscopy. All the hydrophobic interactions identified can be attributed to the appearance of gas layers on the surfaces leading to capillary interactions.     

油酸钠作用下磁铁矿与硫化矿物间异相聚团研究

为了采用聚团-磁选的方式回收微细粒级硫化矿物, 研究了油酸钠作用下, 微细粒硫化矿物与磁铁矿之间的异相聚团机理。结果表明, 静电力和疏水力是硫化矿物与磁铁矿颗粒间形成聚团的主要作用力。pH=4.0时, 2种矿物动电位均小于20 mV, 且油酸钠在两种矿物颗粒表面吸附量最大, 矿物颗粒间易发生异相聚团, 人工混合矿聚团-磁选回收率达到最大, 为87%; pH>7.0时, 2种矿物动电位均大于60 mV, 由于磁铁矿表面油酸钠吸附量大幅降低, 疏水力减小, 导致聚团效果变差, 硫化矿回收率显著降低。