X射线荧光光谱微区分析在铅锌矿石鉴定上的应用

自然界很多矿物存在类质同象现象,它们在显微镜下特征相似难以区分,对于这类矿物的鉴定,需要借助X射线衍射分析、电子显微镜、电子探针分析和离子探针分析等手段,获取矿物的化学成分和结构,为矿物鉴别提供有用的信息。本文以铅锌矿石中比较典型且易于收集的方铅矿(Pb 86.60%、S 13.40%)和闪锌矿(Zn 67.10%、S 32.90%)为例,借助偏反光显微镜,初步鉴定矿石的矿物特征;再利用X射线荧光光谱仪微区分析功能,对铅锌矿石标本进行定性和定量鉴定,对矿石所表现的各种特征做矿物学解释。实验结果表明,铅锌矿石标本中存在S、Pb、Zn、Cd等异常元素,并对闪锌矿标本中Zn、S、Fe、Cd等异常元素进行分布分析,绘制组分的二维或三维分布图显示各元素分布的异常区域高度一致;在电荷耦合器的实时监控下,对铅锌矿石标本靶区进行定点定量测定,根据所测组分含量,并结合矿物化学成分理论值定名为方铅矿和闪锌矿。本方法测定闪锌矿标本各组分的相对标准偏差(RSD,n=11)均小于4%,测定结果与电子探针测定结果吻合。本方法只要将矿石制成光片,无需喷碳处理,即可对铅锌矿石中主次量元素进行原位微区定性和定量分析,测定速度快且不破坏矿石标本,解决了类质同象矿物(如方铅矿和硒铅矿、闪锌矿和含铁闪锌矿等)在光学显微镜下鉴定困难的问题,提高了铅锌矿石定名的准确性,为岩矿鉴定工作提供一种新的技术手段。     

Reflectance spectroradiometry applied to a semi-quantitative analysis of the mineralogy of the N4ws deposit,Carajás Mineral Province,Pará, Brazil

Quantifying the abundance and physicochemical properties of minerals using reflectance spectroradiometry in the visible, near infrared and shortwave infrared (400–2500 nm) regions is an important tool in mineral exploration. In this study, the reflectance spectra of drill cores from the world-class N4WS iron deposit located in the Carajás Mineral Province, Brazil, were obtained. These spectra were validated using X-ray fluorescence (XRF) geochemical analyses and thin sections. The reflectance spectra were collected using a FieldSpec 3 spectroradiometer (ASD, Boulder, Colorado, USA) in 10 drill cores. The mineralogy of the deposit is mainly hematite, with lesser amounts of magnetite, goethite, quartz, kaolinite, gibbsite, smectite, talc, carbonate and chlorite. The mineralogy of the iron deposit was extracted from the spectral data using the geometry (depth and wavelength) of absorption features across the reflectance spectrum removed from the continuum. The depth of the absorption features is proportional to the mineral abundance, and the wavelength is proportional to the mineral chemical composition. The diagnostic absorption features of each mineral were used to determine the mineral abundance and composition. The final products include the abundance of iron (hydro) oxide (11.6% root-mean-square error [RMSE] Fe₂O₃); abundance of aluminous clays (RMSE 6% Al₂O₃); abundance of talc (8% RMSE MgO); identification of clay type (kaolinite, montmorillonite or gibbsite); composition of carbonate (dolomite vs. calcite); and composition of chlorite (Mg vs. Fe). The mineral abundance and composition results provided an effective characterisation of the ore, protore and host rocks and showed variations within the ore body.     

西藏嘎拉勒铜金矿床金和银的赋存状态研究

班公湖-怒江成矿带是西藏重要的铜多金属成矿带。嘎拉勒铜金矿床是该成矿带中发现较晚、研究程度较低且具代表性的矽卡岩型铜金矿床,矿石有用组分中金、银的赋存状态研究相对开展的较少,限制了矿床进一步的综合开发利用。作者通过野外地质调查与采样,采用光学显微镜鉴定、扫描电镜观察和X射线能谱仪测试分析等手段和方法,对矿石成分组分做了详细的研究,重点研究了矿床中金、银的赋存状态及主要载金矿物的特征。嘎拉勒铜金矿床金矿物以自然金、银金矿为主,其次为金银矿,可见粒间金、裂隙金及相对较少的包裹金形式,主要的载金矿物为石英、白云石、方解石、金属氧化物、硫化物及自然铋等。银矿物主要以金银系列矿物形式存在,少量自然银与放射性元素共生,此外,还有少量辉银矿。研究成果填补了该矿区金、银赋存状态研究的空白,对矿床的开发、利用有着重要的指示意义。     

安徽马钢凹山铁矿断层带中粘土矿物质组分的研究

对马钢凹山铁矿区断层带中规模较大的粘土矿,采用化学分析、岩矿鉴定、Ｘ衍射分析、红外吸收光谱分析、差热分析、透射电镜及物理工艺性能等综合分析测试方法进行了研究,查明其岩石、矿石类型及６种类型矿石的物质组分和矿物特征、２组矿石样品的物理工艺性能,在此基础上,从选矿和提高矿石质量等方面提出了意见     

自然重砂成因矿物学特征及找矿指示作用

自然重砂是地质体经自然风化、剥蚀、搬运、沉积等地质作用而分离出的单矿物(或矿物组合)。自然重砂矿物晶体由于仍然保留有许多矿物成因信息,包括颜色、形态、化学成分、物理性质和矿物组合等特征,因此常用于追溯源区地质体或者找矿勘查。这种方法被认为是一种经济实用的找矿方法——自然重砂测量。本文基于全国自然重砂找矿的数据资料,系统梳理了自然重砂的矿物类型、出现频率及其分布等特点,分析了自然重砂的矿物组合和成因矿物学特征,研究了自然重砂矿物的源区烙印、搬运距离及标型指示矿物组合特征,探讨了自然重砂成因矿物学研究意义及其找矿应用前景。自然重砂矿物的颜色、形态及内部结构依然保留着明确的成因矿物学信息:其颜色和晶体形态具有继承性而与其源区母体联系起来,体现源区母体的特性;其矿物组成可分出残余原生重矿物(包括造岩矿物、副矿物、矿石矿物等)和新生重砂矿物两个部分,如赤铜矿、孔雀石等反映着源区岩性体的成分或者赋存状态特征,其矿物组合也在很大程度上继承原生共生矿物而体现诸如有无矿化等意义;重砂颗粒的磨圆度、边界光滑性等表面特征反映搬运距离,有利于明确响应源区母体或者物源,而具有良好的找矿指示意义。     

承德钒钛磁铁矿钒和钛物相的联测分析方法

依据承德地区大庙式钒钛磁铁矿床特征,通过人工重砂分离及单矿物化学分析并结合电子探针、岩矿鉴定结果查明了承德钒钛磁铁矿石中的含钒矿物主要是钛磁铁矿和磁铁矿,次要矿物是钛铁矿和硅酸盐;含钛矿物主要是钛铁矿、钛磁铁矿,次要矿物是金红石、榍石。根据承德钒钛磁铁矿石钒和铁呈正比的关系,选取代表性试样进行了钒钛物相分析项目的确定及溶剂选择的实验,最终确定了钒和钛物相分析测定流程。钒物相分析测定项目为磁铁矿和钛磁铁矿中的钒、钛铁矿中的钒、硅酸盐中的钒及总钒四项;钛物相分析测定项目为钛铁矿中的钛、磁铁矿和钛磁铁矿中的钛、金红石中的钛、硅酸盐中的钛及总钛五项。通过本方法测定的各种含钒和钛矿物含量占矿石中总钒和总钛含量的比例与人工重砂分析定量计算的各种含钒和钛矿物含量占矿石中总钒和总钛含量的比例是相互吻合的。对110件钒钛磁铁矿石样品进行了4种含钛矿物及3种含钒矿物物相分析,结果与实际地质成矿组分符合。本方法实现了钒钛磁铁矿中钒矿物和钛矿物的定量分离,确定了钒和钛物相联测分析流程,可以同时测定钒和钛矿物的含量。     

钕同位素比值~(143)Nd/~(144)Nd标准溶液研制

钕同位素比值(~(143)Nd/~(144)Nd)是Sm-Nd同位素方法的关键量值,由于被测样品的~(143)Nd/~(144)Nd比值变化范围很小,所以对~(143)Nd/~(144)Nd比值测试的精准度要求很高(精度优于0.005%)。为了获得高精度和高准确度的测试数据,分析过程中所用Nd同位素标准物质起着重要作用。以往的Nd同位素标准物质都是氧化钕,经过近三十年有的已消耗殆尽。本文阐述了钕同位素比值~(143)Nd/~(144)Nd标准溶液的研制,经检验标准溶液的均匀性和稳定性良好,由11家实验室协同定值,采用MC-TIMS和MC-ICP-MS方法测定~(143)Nd/~(144)Nd,确定了Nd同位素标准溶液的特性值~(143)Nd/~(144)Nd=0.512438,不确定度为5×10-6。此标准溶液于2015年5月获得国家标准样品证书(批号为GSB 04-3258—2015),可被用于地质、资源、海洋、环境、考古等多种样品~(143)Nd/~(144)Nd比值测定时的仪器校准和分析过程的质量监控。     

Mineralogical and microtextural parameters in metals ores traceability studies

The demand in mineral resources is increasing rapidly, but there is a lack of transparency in the trade of concentrated raw mineral materials because of speculation and involvement in the finance of armed conflicts. Because of the distance between primary extraction and the final production sites it is difficult to check the origin of these products. An identity card is required for mineral commodities, so that trading in the industry can be verified and the traceability of concentrates ensured. This problem may be considered as an inversion process: studying the products sold to identify the original ore. The discriminant parameters are mineralogical composition, identification of textural microfacies of the target minerals, “pseudo-paragenetic sequence”, and the contents and distribution of minor elements of target minerals. For base metal, the selected target minerals are pyrite, for its ubiquity, sphalerite for its ability to host numerous discriminant and potentially valuable minor elements in its lattice and chalcopyrite for its proximity with the two other minerals. The Kolmogorov–Smirnov distance and the Colin–White test are used to compare the chemical composition of the three target minerals. The application to Volcanic Massive Sulfide ore deposits shows that it is possible to distinguish pyrite, sphalerite and chalcopyrite between two ore deposits in the Iberian Pyrite Belt province and seven ore deposits from the Urals province using the selected characteristics. Ore deposits from different provinces may be discriminated using the identity cards, as well as different deposits in the same province.     

Mineralogical and Genetical Aspects of the Doyashiki Kuroko Deposits, Hokuroku Basin, Japan

Abstract. A detail investigation of ore and gangue minerals was performed on the Doyashiki Kuroko deposits, Hokuroku basin, Japan for the first time. Main ore minerals are sphalerite, galena, pyrite, chalcopyrite, tetrahedrite-tennantite and digen-ite. Small amounts of enargite, wittichenite, electrum, covellite, bornite, marcasite and hematite are also observed. Quartz, barite and gypsum are common gangue minerals. Homogenization temperatures and salinities of fluid inclusions in quartz, sphalerite and barite range from 190 to 240C and 3.0 to 5.5 wt% NaCl equivalent, respectively. The FeS contents of sphalerite and Ag contents of electrum were 0.12 to 0.18 mol %, 39.0 to 39.6 atom %, respectively. The chemical composition of digenite as a primary mineral shows high sulfur contents.
These data indicate that ore fluid responsible for digenite and associated ore minerals was characterized by a range of high sulfur fugacity with a moderate formation temperature. This is concordant with the mineral assemblage of bornite-pyrite and chalcopyrite, which shows high sulfur fugacity conditions. It seems that the mineralization closely associated with acidic volcanism has occurred around 13 Ma of Middle Miocene on the seafloor at the depth of about 1500 m.     

安徽省金寨县沙坪沟钼矿床有益成分及其赋存状态

通过一系列岩矿鉴定、电子探针分析、物相分析、X衍射分析及化学分析数据,总结出沙坪沟钼矿床的矿石矿物组成、结构构造、有益组分、伴生有用组分及其赋存状态、主要赋存矿物的分子式等。其有益组分为Mo,伴生有用组分为S;Mo呈辉钼矿赋存于矿石中,S呈辉钼矿、黄铁矿的阴离子赋存于矿石中。     

Ore and Skarn Mineralogy of the Yamato Mine,Yamaguchi Prefecture,Japan, with Emphasis on Silver‐, Bismuth‐, Cobalt‐, and Tin‐bearing Sulfides

Assemblages and chemical compositions of ore minerals from the Yamato mine, Yamaguchi Prefecture, Japan, were investigated in detail to clarify its characteristics as a skarn deposit. Special attention was paid to silver‐, bismuth‐, cobalt‐, and tin‐bearing sulfide minerals and native gold at the mine, which are described here for the first time. Samples of arsenopyrite‐dominant massive ore, and garnet‐rich, clinopyroxene‐garnet‐rich, and wollastonite‐bearing skarn ores were collected from the mine dump. Arsenopyrite is the most abundant ore mineral (>80 vol.%) in the massive ore, in association with both As‐poor/free and As‐bearing pyrite. The major ore minerals in the skarn specimens are pyrite, pyrrhotite, arsenopyrite, chalcopyrite, galena, and sphalerite, along with minor argentite, Ag‐Pb‐Bi sulfate, matildite, bismuthinite, native bismuth, molybdenite, scheelite, stannite, stannoidite, cassiterite, cobaltite, gersdorffite, and Co‐rich violarite. In addition, native gold is observed in the interstices of gangue minerals. Based on the mineral assemblages and textures of the specimens examined, the major ore minerals formed in the early stage of mineralization, and the Bi‐, Ag‐, Co‐, Ni‐, As‐ and Sn‐mineralization occurred in the middle stage. Native gold was deposited in the late stage. The estimated formation temperature of the middle mineralization stage was 312±5 °C, according to iron and zinc partitioning between stannite and coexisting sphalerite. The mineralogical properties and mineralization process of the Yamato mine are consistent with those of common skarn‐ and vein‐type ore deposits associated with ilmenite‐series granitoids in the San‐yo and San‐in districts.     

广东梅县锰矿物质成份的研究

随着我国钢铁工业和化学工业的迅猛发展,对锰矿资源的需求,日益增加.梅县锰矿公司对该县的锰矿地质和锰矿生产做了大量工作.在前人工作的基础上,我们在锰矿资源的调研中,曾对广东省梅县的宝山岗、白沙坪、桃尧大华、宝坑、仙水塘、磔角坑、车陂等地的锰矿体、进行过采样工作.经室内鉴定后、梅县的锰矿石有优质的放电锰矿石和冶金用锰矿石、矿床规模属于中小型.梅县锰矿资源的生产,继续已有20多年的历史,在矿床的质和量方面尚需做更深入的研究,以便为矿山开采和锰矿生产提供更充分的依据.本文是对锰矿物质成分初步研究的部分结果.     

The Processing Mineralogy for Lead and Zinc Oxide Ore in Sichuan

Using variety of modern testing methods, the processing mineralogical characteristics for a lead and zinc oxide ore in Sichuan were studied systematically. The chemical analysis result shows that the lead and zinc oxide content exceeding the minimum industrial grade and iron ore, total iron content reaches a minimum industrial grade and associated with gold and silver; The mineralogical analysis result shows that lead and zinc mineral composition and configuration are very complexity. The zinc minerals and zinciferous minerals are sphalerite, hemimorphite, Smithsonite, Hydrozincite, zinc chlorite, limonite, zinc dolomite and zincocalcite; lead minerals and plumbiferous minerals are mainly galena, cerussite, anglesite, limonite and Coronadite; The minerals disseminated grain size are very fine and mineral dissemination characteristics are very complex ; expected theoretical recoveries for lead and zinc were 72% and 67% respectively. The results of this study provide basic data and theoretical basis for ore dressing.     

Mineralogy,Sulfur Isotope and Fluid Inclusion Studies of Hydrothermal Ore at the Hakurei Deposit,Bayonnaise Knoll,Izu‐Bonin Arc

Sulfide and sulfate ore samples collected from the Hakurei deposit of the Bayonnaise knoll were examined for the occurrence and chemical composition of minerals, including the sulfur isotopes and the microthermometry of fluid inclusions. Massive sulfide ore, mineralized volcanic rock, and anhydrite ore occur in descending order, from the seafloor to the bottom of the cored sample. The massive sulfide ore is dominated by sphalerite and accompanied by tennantite, chalcopyrite, and pyrite with lesser amounts of galena, enargite, and covellite. Amorphous silica is commonly precipitated on the surface of the sulfide minerals. As‐bearing minerals such as tennantite, enargite, and luzonite are common, while galena and Sb‐rich tetrahedrite are scarce. The mineral abundance and chemical composition of the minerals differs from that found in chimneys of the deposit. The sulfur isotope compositions in the minerals are +3.1–5.2‰ for sulfides and +19.6–21.8‰ for sulfate minerals. The homogeneous nature of the sulfur isotopes suggests that sulfur incorporated in the Hakurei deposit came from the reduction of aqueous sulfate in seawater.     

江西洋鸡山金矿矿相学研究

江西洋鸡山金矿矿相学研究楼亚儿（中国地质大学，北京１０００８３）关键词洋鸡山金矿，矿相学，矿物标型特征，隐爆角砾岩江西瑞昌洋鸡山金矿为长江中下游钢－金矿田中一个典型的独立金矿床。矿体赋存在燕山早期石英闪长玢岩与五通组地层接触带附近的隐爆角砾岩筒中，矿...     

Relation between chemical composition and particle-size distribution of ores in the profile of nickeliferous laterite deposits of the Rio Tuba Mine, Philippines

Lateritic Ni ore mined in the Rio Tuba Mine, Philippines, derived from ultramafic rock by tropical intense weathering, is generally composed of two accumulated zones, an upper laterite zone and a lower saprolite zone. These two zones are very different in appearance, mineral assemblage, chemical composition, and in other ways. A transitional zone may be seen between the upper and lower zones, but it does not develop to any appreciable thickness. Although serpentine and goethite are still predominant in the constituent minerals, other clay minerals are increasing.

The transitional zone may be subdivided into three groups based on chemical composition. The behaviour of the chemical composition in this horizon indicates a complicated process of component transportation under the weathering process.

In the ore, chemical components are closely related in particle size of constituent minerals. In the laterite - transitional - saprolite sequence, a common variation range and tendency in chemical composition for each particle size can be seen. However, taking samples with the same particle size the chemical composition obviously differed, representing the characteristics of the components for each zone.

Concerning the correlation coefficient of the chemical components of each zone, a somewhat different inter-component relationship can be seen in these zones. These differences of correlation suggest the different complicated lateritized conditions under which they are formed.     

松辽盆地西南部DL铀矿带铀赋存状态及矿物组成特征

DL铀矿带是松辽盆地近年找矿的新发现。文章利用扫描电镜、电子探针和自动矿物参数定量分析系统等测试手段对该区矿石样品进行了铀赋存状态研究,结果表明:研究区铀主要以沥青铀矿、含锆铀矿物、含钛铀矿物等独立铀矿物以及黏土吸附、有机质吸附、锐钛矿吸附等吸附铀形式存在,铀矿物呈微粒状、细脉状、块状和团块状产出,空间上与磷灰石、硒铅矿、黄铁矿、有机质和碳酸盐等关系密切,与周边铀矿床的铀存在形式略有差别,其中含锆铀矿物在砂岩型铀矿中属首次发现。矿物组成以石英、长石、黏土矿物和碳酸盐为主,此外还有一定量的钛铁氧化物、重晶石、铁氧化物和少量独居石、磷钇矿、硒铅矿等副矿物。利用电子探针的铀定量分析数据和自动矿物参数定量分析系统的铀矿物定量分析数据,首次定量计算了不同存在形式铀的分布率,结果显示:独立铀矿物中沥青铀矿和含锆铀矿物的分布率最高,吸附铀以黏土矿物吸附占优势,有机质和锐钛矿吸附次之。铀赋存状态及矿物组成的精细厘定对矿床成因与选冶工艺研究等具有重要意义。     

顾及太空风化效应的虹湾地区矿物含量反演

月表矿物含量反演是研究月球地质起源和演化的关键.太空风化作用普遍发生在月球表面,对矿物纯净光谱造成了不可忽视的影响,它弱化光谱吸收特征, 降低反射率,影响矿物含量遥感反演精度.基于Relab光谱库和Hapke辐射传输模型,将月表 4种矿物(单斜辉石、斜方辉石、斜长石、橄榄石)的二向性反射率转换成同向性的单次散射反照率,然后计算矿物的光学常数;再根据亚微观金属铁SMFe(submicroscopic metallic iron)的质量分数模拟6种不同程度太空风化效应,得到端元矿物的反射率光谱;最后基于上述方法,利用多端元线性分解方法和M3(moon mineralogy mapper,月球矿物绘图仪)高光谱数据反演不同风化程度下的矿物含量,得到月表虹湾地区辉石、斜长石、橄榄石3种矿物的含量分布.实验表明,利用多端元线性分解可以有效模拟太空风化效应对矿物光谱的影响,是研究太空风化效应影响下矿物识别及含量反演的一种行之有效的方法.      

Unsupervised ore/waste classification on open-cut mine faces using close-range hyperspectral data

The remote mapping of minerals and discrimination of ore and waste on surfaces are important tasks for geological applications such as those in mining. Such tasks have become possible using ground-based, close-range hyperspectral sensors which can remotely measure the reflectance properties of the environment with high spatial and spectral resolution. However, autonomous mapping of mineral spectra measured on an open-cut mine face remains a challenging problem due to the subtleness of differences in spectral absorption features between mineral and rock classes as well as variability in the illumination of the scene. An additional layer of difficulty arises when there is no annotated data available to train a supervised learning algorithm. A pipeline for unsupervised mapping of spectra on a mine face is proposed which draws from several recent advances in the hyperspectral machine learning literature. The proposed pipeline brings together unsupervised and self-supervised algorithms in a unified system to map minerals on a mine face without the need for human-annotated training data. The pipeline is evaluated with a hyperspectral image dataset of an open-cut mine face comprising mineral ore martite and non-mineralised shale. The combined system is shown to produce a superior map to its constituent algorithms, and the consistency of its mapping capability is demonstrated using data acquired at two different times of day.