希瓦氏奥奈达菌MR-1还原针铁矿的实验研究及地球化学意义

本文实验研究了希瓦氏奥奈达菌株(Shewanella oneidensis MR-1,以下简称MR-1)在pH为中性的厌氧条件下还原针铁矿的过程,探讨了MR-1菌异化还原针铁矿的动力学特征。采用邻菲罗啉分光光度法检测了反应前后溶液中铁含量的变化,利用扫描电子显微镜、粉晶X射线衍射和激光拉曼光谱分析了针铁矿及其还原产物的形貌特征和物相组成。结果表明,针铁矿在厌氧条件下可被MR-1还原,生成磁铁矿、菱铁矿等次生矿物。本文认为针铁矿的微生物异化还原过程以直接接触机制为主,同时存在间接还原机制;溶液中的Fe2+与CO32-、SO42-等沉淀生成菱铁矿等次生产物,同时部分Fe2+、Fe3+离子可吸附于矿物表面,甚至能引起矿物相的转化,两者共同构成了针铁矿的次生分解路径。     

Euro-Standards of Iron Ores

The chemical composition of six iron ore standards is presented. Twenty selected laboratories in the member countries of the European Coal and Steel have participated in their certification.     

German Standards of Iron Ores

The chemical composition of eight german ore standards, seven iron ores and one manganese ore, is presented. A certificate of analysis supplied with each sample is given as an example; it contains the names of the co-operating laboratories, the- mean value obtained by each laboratory for each element and a statistical evaluation of the laboratory means. A summary is also given of the methods used.     

On the Mechanism of Transformation fromPrimary Ores into Oxidized Ores in FinelyDisseminated Gold Deposits

This paper, taking the finely disseminated gold deposits in southwestern Guizhou and northwestern Guangxi as examples, discusses the difference between the occurrence of primary ores and that of oxidized ores, analyzes the occurrence mechanism in terms of crystallochemistry and geochemistry, and especially studies the chemical model for supergene leaching transformation of clay minerals in the two types of ores. This study proposes a new idea for dressing and smelting technology for primary gold ores.     

针铁矿与盐酸反应的化学动力学研究

本文研究了针铁矿αFeOOH与盐酸反应的化学动力学特性,测定了它们的反应级数、速率常数、实验活化能和指(数)前因子。     

东方矿体经济评价系统

:研制成功矿体评价系统 ,可做矿体圈定、经济评价、绘图等项工作 ,并对用于对开采矿体的动态管理     

重晶石矿石成分分析标准物质研制

研制了7个重晶石矿石成分分析标准物质。其中,GSO-1为铁矿型重晶石,GSO-2、GSO-3为萤石型重晶石,GSO-4、GSO-5为石英型重晶石,GSO-6为硫化物型重晶石,GSO-7为黏土型重晶石。样品采用陶瓷衬里的球磨机加工,加工后样品粒度达到-0.074 mm。采用X射线荧光光谱法检验了钡、铜、铅、锌、锆、铝、硅、铁和钙共9种元素的均匀性,并进行振动试验。8个实验室参加定值工作,提供了硫酸钡、氧化钡、三氧化硫和锶的7个标准值,全三氧化二铁的2个标准值,氟化钙的1个标准值及铜、铅、锌和水溶盐等标准值或参考值。2009年4月,7个样品已被国家质量监督检验检疫总局批准为国家一级标准物质,编号为GBW 07811~GBW 07817。     

Applied Mineralogy Studies of Rare-Earth Ores

New attention has been given to the resources of rare earth minerals over the last years. The natural shortage of these elements in the Earth’s crust and trade restrictions recently imposed by China, motivated the Brazilian Government to encourage new projects by inserting the exploitation of rare earths in the National Mining Plan, which deals with industry strategic issues in the country, helping to reduce current importation. The incentives can be in the choice of future targets for mineral exploration and for the development of laboratory studies and pilot scale processing tests.     

复杂矿石中滑石的测定

含滑石复杂矿石试样经650℃焙烧,使其中绿泥石、菱镁矿等变得能迅速溶于1+1 HCl中,而滑石溶解率很低。残渣用HF-HClO_4或KOH处理,用火焰原子吸收法或滴定法测定MgO,计算滑石量。10余种共存矿物在一定范围内不干扰测定。     

铬铁矿中亚铁的测定方法

采用硫-磷混合酸微波消解对难溶的钒钛磁铁矿进行前处理,用5-溴-PADAP-过氧化氢分光光度法测定矿样中的钒,优化了微波消解的实验条件。加入浓磷酸和40 g/L氟化钠溶液分别消除了共存常量元素铁和钛的干扰。方法检出限为0.004μg/mL,线性范围为0.01~1.0μg/mL。应用于实际钒钛磁铁矿样品中钒的测定,重现性好,检出限较低,灵敏度较高,能够满足简单、快速、批量分析的要求。     

铜仁大硐喇汞矿田中锌矿分布规律及找矿远景

简要分析区域成矿地质背景、地层构造及矿床地质特征,重点论述汞矿田中锌矿分布规律。矿体分布于中寒武统敖溪组第五段二亚段,富集于背斜轴部、断层两侧,并受次级褶皱控制,其构造控矿明显,锌矿化与硅化、沥青化、白云石化、方解石化关系密切,探讨铜仁大硐喇汞矿田及相邻区具类似控矿地质条件的找矿远景。     

The First Find of Goethite Crusts in the Sea of Japan

Doklady Earth Sciences - Ferruginous (goethite) mixed-type hydrothermal–hydrogenetic crusts, which were found in the Sea of Japan for the first time, are described. Compared to manganese...     

A Study of Chromium Adsorption on Natural Goethite Biomineralized with Iron Bacteria

Goethite, especially biogenic goethite, has high specific surface area and great capacity for the adsorption of many contaminants including metal ions and organic chelates. Chromium is a redox actively toxic metal ion that exists as either Cr^Ⅲ or Cr^Ⅵ in nature, and as such it is essential to understand its behavior of adsorption on natural goethite mineralized by iron bacteria, as Gallionella and Leptothrix in water body. The adsorption of Cr^3＋ and Cr^Ⅵ on naturally biomineralized goethite is studied in this paper. The results show that both Langmuir and Freundlich adsorption isothermal models are able to accurately describe the adsorption of these two ions. Investigation of SEM/EDS, TEM/EDS indicates that the two ions do not adsorb homogeneously on goethite owing to the different microstructures of goethite, and that the microspherical goethite has a greater adsorption capacity for chromium ions than the helical one. XPS data show that redox reaction of chromium on the surface of biomineralized goethite takes place in the adsorption of both Cr^3＋ and Cr^Ⅵ. The CrvI adsorbed on biogoethite is much easier to transform into CrIII than the oxidization of Cr^Ⅲ on the bio-goethite.     

钼矿石中氧化钼的浸取条件研究

以Cu~(2+)-稀HCl混合溶液为MoO_3的选择性溶剂,Cu~(2+)能有效地消除酸溶硫化物溶解时产生的H_2S对MoO_3测定的干扰。选用催化极谱法测Mo可进一步简化操作手续,提高测定灵敏度。所拟方法用于一般钼矿石物相分析,尤其对含酸溶硫化物较多的矿石均能得到满意的结果。     

Selenium in Volcanogenic Massive Sulfide Ores

Doklady Earth Sciences - This paper describes the Se proper minerals first identified in the primary ores in Uralian volcanogenic massive sulfide (VMS) deposits. The investigation was carried out...     

利用漫反射光谱鉴定红粘土中针铁矿和赤铁矿

针铁矿(Gt)和赤铁矿(Hm)是广泛存在于土壤和沉积物中的重要铁矿物。这两种矿物在土壤和沉积物中含量很低,常规的测试手段很难有效地测定其含量。利用反射光谱联合加热处理的方法,可对土壤及沉积物样品中针铁矿和赤铁矿进行定性或半定量测定。实验结果显示,样品加热到300℃后,针铁矿的反射光谱的一阶导数特征峰发生了变化,赤铁矿的一阶导数特征峰却没有明显的变化。因此加热前后样品反射光谱一阶导数的变化取决于针铁矿和赤铁矿的含量。利用这种方法估计黄土高原第三纪红粘土样品中的赤铁矿含量约为0.3%～0.4%,针铁矿含量约为0.5%～1%。     

焙烧镁菱铁矿磁选试验

本文根据贵州省赫章县某地焙烧菱铁矿矿石性质,进行了磁选试验研究,结合X粉晶分析和单矿物化学分析,确证了该矿石为铁、镁、锰类质同象形成的镁菱铁矿(Fe、Mg、Mn)CO3矿石,属于难选矿石。通过磁选试验研究,指出了该矿石的的应用途径。     

Goethite Morphology and Composition in Banded Iron Formation, Orissa, India

Iron ore deposits are generally described in terms of size, grade and chemical composition rather than the mineralogical and microstructural characteristic of different ore types. It is essential, however, to know the morphology, microstructure and chemical composition of individual minerals for optimum mineral processing. Goethite is reported to occur as a ubiquitous phase in many iron ore types and is particularly abundant in the Precambrian banded iron ore formation of north Orissa, India. Goethite from the Bonai–Keonjhar Belt in Orissa has been examined in terms of its morphology and microstructure in relation to chemical composition. Electron microscopy indicated several goethite morphotypes including botryoidal, nodular, spheroidal, platy, stalactitic and flaky. These different morphotypes display intergranular, intragranular, wedge, reniform, comb, prismatic, cavity-line and bead microstructures. In situ analysis using electron probe microanalyzer indicated a wide compositional variation among the different morphotypes and microstructures. Goethite replacing hematite is generally devoid of deleterious elements while re-precipitated goethite generally contains adsorbed alumina, silica and/or phosphorus. Nodular goethite commonly has a high phosphorus level while botryoidal, spheroidal and platy goethite often contains increased combined alumina and silica. Goethite having a reniform, wedge, intergranular or intragranular microstructure is highly water bearing and cryptocrystalline in nature. During dehydration, bead, comb, cavity-lined or prismatic goethite develop, which are more crystalline and which have a higher iron concentration. Goethite with a wedge, prismatic or bead-type microstructure has a higher adsorption of silica (2–4%), while goethite having an intergranular, bead or prismatic microstructure invariably contains appreciable phosphorus, generally at levels deleterious to processing.     

硫氰酸汞分光光度法测定矿石中氯

岩石样品经氧化锌-碳酸钠烧结预处理,用水浸取后澄清,取清液用硫氰酸汞间接分光光度法进行氯的测定。方法用于实际样品的分析,结果与其他方法测定值一致,误差均在允许范围内;对氯含量为1.08%(质量分数)的样品重复测定6次,精密度(RSD)为1.74%。方法适用于0.02%~2%氯的测定,并且方法简单、快捷、准确,避免了用高氯酸调节酸度的繁琐操作。