阳极泥及碲回收物料中高含量碲的测定

采用重铬酸钾容量法,测定铜铅阳极泥及碲回收物料中高含量碲。针对阳极泥样品成分复杂的特征,确定了最佳溶样介质;探讨了Cu^2 ,Cd^2 ,Bi^3 ,Ag^ ,Sb(Ⅲ）,As（Ⅲ）,Pb^2 ,Se（Ⅳ）,Sn（Ⅳ）,Au(Ⅲ）等共存元素的影响及其消除方法;改善了滴定条件。方法适用于w(Te)＞1％碲的测定,样品分析结果与原子吸收法测定结果一致,RSD（n＝5）为0.4％－4.1％。     

Extreme Enrichment of Tellurium in Deep-Sea Sediments

Tellurium is a sort of scattered rare element on the earth. Its concentration is very low in earth＇s crust, only 1.0 ng/g. However, it has extremely high abundance in Co-rich crusts, marine polymetallic nodules, deep-sea sediments and aerolites. To find out the origin of tellurium enrichment in deep-sea sediments, we analyzed and compared tellurium concentrations and helium isotope compositions in the magnetic parts and those in the bulk parts of deep-sea sediments. The result indicates that the helium content, 3He/4He ratio and tellurium concentration are obviously higher in the magnetic parts than those in the bulk parts. The 3He abundance varies synchronously with the tellurium concentration. 3He and Te have a distinct positive correlation with each other. It is the first time that the paper brings forward that the extreme enrichment of tellurium in deep-sea sediments, like helium isotope anomalies, probably results from the input of interplanetary dust particles （IDPs）. Similarly, the extreme enrichment of tellurium in marine polymetallic nodules and Co-rich crusts is possibly related to IDPs.     

碲矿物综述

对世界上已经发现报道的, 以及被国际矿物学会新矿物和矿物命名委员会批准承认的分散元素碲的172个矿物种类作了初步总结,并对碲矿物 的晶体化学组成、产出的地质条件和碲元素的地球化学特征,以及我国对碲矿物学研究的现 状和存在的问题进行了综述和探讨。     

深海沉积物中碲异常的成因

碲在地球上是一种稀有分散元素，碲在地壳中的丰度很低，仅为1.0ng/g；但碲在富钴结壳、海底多金属结核、党海沉积物和陨石中的丰度异常高。为了查明深海沉积物中碲异常的原因，笔者对比分析了深海沉积物中磁性部分与全岩的碲含量和氦同位素组成。结果显示磁性部分的He含量和3He/4He比值及Te含量较全岩的值明显偏高；3He含量与Te含量同步变化；在3He－Te关系图上，二者具明显的正相关关系。本文首次提出深海沉积物中的碲异常与氦同位素异常一样可能是由宇宙尘注入引起的；海底多金属结核和富钴结壳中的碲异常可能也与宇尘有关。     

碲在官田黄铁矿矿床中的聚集及地球化学

碲是官田黄铁矿矿床中的重要伴生组分,高度聚集在寄主矿物黄铁矿中,含碲矿物是楚碲铋矿、赫碲铋矿和碲铋矿。成碲和聚碲的物理化学条件是：压力低于１０ＭＰａ,温度１４０～２２０℃,含碲流体的盐度低于１２ω（ＮａＣｌ）,离子类型为ＳＯ２－４－Ｋ＋－Ｃａ２＋型,ｐＨ值为４．４～５．８,Ｅｈ值为－０．５Ｖ,ｆＯ２＜１０－２５×１０５Ｐａ,ｆＣＯ２＜１０１．８×１０５Ｐａ,ｆＳ２为（１０－２１．３４～１０－１５．７２）×１０５Ｐａ,ｆＴｅ２为（１０－１１．９３～１０－８．７２）×１０５Ｐａ。含碲热液具多来源,成碲和聚碲时期以天水为主导。碲的可能迁移形式是［ＴｅＳ３］２－和［ＡｕＴｅＳ３］－。文章最后与大水沟独立碲矿床进行了综合对比。     

富碲化物金矿床中碲的成矿作用研究进展

碲(Te)属于稀散元素,是我国的战略性关键矿产资源之一,富碲化物金矿床是碲元素的重要载体.将富碲化物金矿床划分为3种成因类型,分别为造山型金矿床、浅成中-低温热液型金矿床以及与碱性岩浆岩有关的金矿床.富碲化物金矿床可以形成于岛弧、大陆边缘、弧后盆地、绿岩带等多种构造环境,常受区域性断裂构造控制,其围岩专属性不强,矿床中存在大量碲化物,与自然金和硫化物伴生产出.成矿作用常可划分为3个阶段:石英-黄铁矿阶段、石英-多金属硫化物-碲化物阶段、石英-碳酸盐阶段,其中金和碲主要在第二阶段发生沉淀富集.成矿流体一般为中-低温、中-低盐度,呈弱酸性-中性,具有较高的f_Te2.富碲化物金矿床中的碲主要来源于地幔、岩浆热液和赋矿围岩.碲在流体中可以呈碲氯络合物、碲硫络合物、碲氢络合物等形式迁移,也可呈气态迁移.引起碲发生沉淀的因素主要为温度或/和压力的变化、水岩反应、流体混合、流体不混溶(沸腾)、含碲气体的冷凝以及多因素的叠加.在碲的成矿作用研究中,应重视碲化物结构和成分的微区原位分析、碲同位素分析以及热力学分析.     

碳酸盐岩地区古风化壳岩溶储层

世界整装大油气田均以海相盆地为主,储集类型首推碳酸盐岩岩溶孔洞+裂缝。岩溶发育的程度除相控外,层序不整合界面与区域性地层不整合面的复合面,在表生成岩作用环境下可形成碳酸盐岩古风化壳型岩溶。塔里木盆地和鄂尔多斯盆地奥陶系古喀斯特油气藏的重大突破,佐证了碳酸盐岩岩溶储层的特殊意义。我国海相盆地碳酸盐岩风化壳岩溶的形成和演化,均与加里东构造旋回中的幕次古隆起和海平面下降共耦,埋藏期和热水溶蚀的叠加可改善岩溶的储集性能。在大面积覆盖的油气田区预测古风化壳型的岩溶储层,可通过地震剖面追踪区域性地层不整合面和层序界面,圈出古岩溶的时空展布、推测古岩溶地貌以及与不同层位岩性相的关系。孔洞充填方解石与碳酸盐围岩的氧碳同位素有别,前者的Z值小于120,是反馈淡水岩溶环境的重要标志之一。     

原子荧光光谱法测定铜矿中硒和碲

介绍了铜矿中Ｓｅ,Ｔｅ的测定方法,样品经ＨＮＯ３－ＨＣｌＯ４分解,以含ＨＣｌＯ４的０．２ｍｏｌ／ＬＨＣｌ溶液通过７４３型阳离子树脂分离Ｃｕ,原子荧光光谱法测定Ｓｅ,Ｔｅ。     

Chemistry and Occurrences of Native Tellurium from Epithermal Gold Deposits in Japan

The chemistry and mode of occurrences of native tellurium in the epithermal gold ores from Teine, Kobetsuzawa, Mutsu, Kawazu, Suzaki and Iriki in Japan are examined. Mineral assemblages in contact with native tellurium are: quartz‐sylvanite at Teine, quartz‐hessite‐sylvanite‐tellurantimony at Kobetsuzawa, quartz at Mutsu, quartz‐stutzite‐hessite‐sylvanite‐tetradymite at Kawazu, quartz at Suzaki, and quartz‐goldfieldite at Iriki. The peak patterns of XRD for native tellurium from these six ores are nearly identical to that of JCPDS 4–554. Their chemical compositions of Te range from 98.16 to 100.73 wt.%, showing nearly pure tellurium. Other elements detected are: Se of 0–0.85 and Cu of 0–0.74 at Teine, Sb of 0.45–0.47 and Se of 0.19–0.27 at Kawazu, Se of 0.22–1.11 and Sb of 0–0.49 at Suzaki, and Cu of 0.69–0.98, As of 0.22–0.28 and Bi of 0–0.22 wt.% at Iriki. No other elements are detected in the ores of Kobetsuzawa and Mutsu. The ranges of associated minor compositions are consistent with those of the experimental phase. The differences would be related to associate minerals. The mineral assemblages in these ores agree well with the previously proposed experimental phase relations in Au‐Ag‐Te ternary system for 120–280°C. The Suzaki ore has high Te‐Au assemblage: from calaverite‐sylvanite‐krennerite via native tellurium to petzite, with changing mineralization stage, whereas the Kobetsuzawa and the Kawazu ores have high Te‐Ag assemblage of tellurium‐hessite, and native tellurium‐stutzite‐hessite‐sylvanite, respectively. The Teine ore has intermediate assemblage of native tellurium‐sylvanite. The mineral assemblages in the Au‐Ag‐Te system are related to the hydrothermal environment especially to the pH condition, i.e. Au rich assemblages under acidic and Ag rich assemblages under intermediate pH conditions, being supported by alteration mineral species. The other telluriferous epithermal gold deposits not in association with native tellurium such as Agawa, Date, Takeno, Chugu, Chitose, Sado and Kushikino are estimated to have been formed under higher pH conditions as adularia and calcite occur in these deposits. The pH‐Eh diagram for aqueous tellurium species and tellurium minerals at 250°C indicates that the region of native tellurium occurs between those of aqueous telluride and tellurous species at lower pH, being consistent with their mineral assemblages in ores and alteration envelopes.     

Tellurium: Should it be isotopically anomalous in the Allende meteorite?

Isotopically anomalous Te is a by-product of the nuclear processes in zones of supernovae that have been proposed as sources for isotopically anomalous Xe. The calculated composition of the anomalous Te is roughly consistent with the disputed measurements made by Balladet al. (1979) and Oliveret al. (1979) of samples of the Allende meteorite with the exception that the large ¹²³Te overabundance reported by Oliveret al. (1979) is not predicted by the theory.     

氢化物发生-原子荧光光谱法测定地球化学样品中痕量碲

采用焙烧富集分离地球化学样品中痕量Te,并用氢化物发生原子荧光光谱法测定。通过实验确定出方法的最佳实验条件,在此条件下获得的检出限为0.005μg/g,线性范围0.025~10μg/g,精密度(RSD,n=8)为5.03%~9.24%。方法已用于国家一级地球化学标准物质中痕量Te的测定,结果与标准值基本相符。     

Fluids in metamorphic rocks

Basic principles for the study of fluid inclusions in metamorphic rocks are reviewed and illustrated. A major problem relates to the number of inclusions, possibly formed on a wide range of P–T conditions, having also suffered, in most cases, extensive changes after initial trapping. The interpretation of fluid inclusion data can only be done by comparison with independent P–T estimates derived from coexisting minerals, but this requires a precise knowledge of the chronology of inclusion formation in respect to their mineral host.

The three essential steps in any fluid inclusion investigation are described: observation, measurements, and interpretation. Observation, with a conventional petrographic microscope, leads to the identification and relative chronology of a limited number of fluid types (same overall composition, eventually changes in fluid density). For the chronology, the notion of GIS (Group of synchronous inclusions) is introduced. It should serve as a systematic basis for the rest of the study. Microthermometry measurements, completed by nondestructive analyses (mostly micro-Raman), specify the composition and density of the different fluid types. The major problem of density variability can be significantly reduced by simple considerations of the shape of density histograms, allowing elimination of a great number of inclusions having suffered late perturbations. Finally, the interpretation is based on the comparison between few isochores, representative of the whole inclusion population, and P–T mineral data. Essential is a clear perception of the relative chronology between the different isochores. When this is possible, as illustrated by the complicated case of the granulites from Central Kola Peninsula, a good interpretation of the fluid inclusion data can be done. If not, fluid inclusions will not tell much about the metamorphic evolution of the rocks in which they occur.     

Alkali-zirconosilicates in peralkaline rocks

Based on the crystal chemistry of alkali-zirconosilicates (AZS), it is argued that Zr, in silicate melts, is a network-modifier rather than a complex-former. With the aid of silicate melt theory the late crystallization of AZS in peralkaline melts can be explained. The high ks/ns and high Q calculated in some norms of peralkaline rocks but not expected from the modes, is the result of calculating ZrSiO₄ rather than (K,Na)₂ZrSiO₅·xSiO₂.     

Uranium in metamorphic rocks

The distribution of U has been studied in two metamorphic rock-series with a gradient of regional metamorphism. One series ranges from the lowest greenschist to amphibolite facies and the other one shows increasing metamorphic grade from amphibolite to granulite facies. Several medium and high pressure granulitic inclusions from alkali basalts were also analyzed. The abundances of U in the rocks do not appear to be affected by metamorphism below the granulite facies grade. Granulites are depleted in U in comparison with equivalent rocks of amphibolite facies grade. There are also differences in their U distribution, as the bulk of U in amphibolite facies rocks is located along the fractures and cleavage planes of ferro-magnesian minerals and in U-rich accessories, while in granulites, most of the U resides in accessory minerals. It seems that the depletion of U in granulites is due to a loss of U which is not located in accessory minerals or in the crystal structure of rock-forming minerals and may also be related to a migration of hydrous fluids, perhaps during dehydration.     

Magnetic anisotropy in rocks

In any rock six kinds of magnetic anisotropy can be distinguished, viz.: (1) shape alignment of grains; (2) alignment of crystals with magneto-crystalline anisotropy; (3) alignment of magnetic domains; (4) the stringing-together of magnetic grains, which is a special case of (1); (5) stress-induced anisotropy; and (6) exchange anisotropy. Each of these anisotropies, together with the method of measurement and practical uses in the fields of geology and geophysics, is discussed.     

氢化物发生-原子荧光光谱法直接测定地球化学样品中痕量碲

采用硝酸-氢氟酸-高氯酸溶解样品,以Fe3 作减缓剂,不需分离富集,用氢化物发生-原子荧光光谱法直接测定地球化学样品中痕量碲.对测定介质、KBH4浓度、铁盐的作用等条件进行试验.方法检出限为0.0031μg/g,精密度(RSD,n=11)＜6.10%.方法用于国家一级地球化学标准物质中痕量碲的测定,结果与标准值一致.     

氢化物发生-原子荧光光谱法直接测定多金属矿中的硒和碲

用硝酸-氢氟酸-高氯酸分解多金属矿物样品,在6 mol/L盐酸介质中,以Fe3+盐为减缓剂,直接在双道原子荧光光度计上同时测定多金属矿中硒和碲。该方法用同一混合酸一次分解样品,不经分离富集,同时测定硒和碲,过程简单快捷,适合于批量样品的检测。将样品与标准曲线同时分解至冒高氯酸白烟,从而准确地测定多金属矿物样品中硒和碲的含量。方法检出限为硒0.032μg/g,碲0.023μg/g;方法精密度(RSD,n=8)为硒<4.0%,碲<7.0%。经国家一级标准物质GBW 07283、GBW 07233、GBW 07234验证,硒和碲的测定值与标准值吻合。