辉锑锡铅矿的穆斯堡尔谱及其晶体化学研究

辉锑锡铅矿是结构复杂而尚未确定,以及晶体化学尚有争议的一种稀有矿物。X射线衍射结果表明其结构是由假四方亚层(称T层)和假六方亚层(称H层)穿插组成的层状结构。T层的化学成分具有MeS形式,H层则具有MeS_2形式。本文通过广西大厂的辉锑锡铅矿的穆斯堡尔谱研究,确定了矿物中Sn的大部分为Sn~(4+),而Sn~(2+)只占较少的部分;Fe中含有Fe~(3+)和Fe~(3+)。它们在T层和H层中的分布为Sn~(2+)(T)占5.6%,Sn~(4+)(T)占25.9%,Sn~(4+)(H)占68.5%,Fe~(2+)(T)占59.5%,Fe~(3+)(H)占40.5%。从Sn、Fe的穆斯堡尔谱参数还可看出H层的共价性比T层的强。     

广西大厂锡石-硫化物多金属矿田中辉锑锡铅矿矿物学研究

本文对中国广西大厂锡石-硫化物多金属矿田中辉锑锡铅矿进行了产出地质条件,共生组合及其形成条件的研究,并通过化学成分、X光粉晶衍射、晶胞参数测定及其晶体结构模式,~(119)Sn和”Fe穆斯堡尔谱研究,初步确定大厂辉锑锡铅矿属富铅端员的“正常”辉锑锡铅矿,其中锡和铁均为Sn~(4-)和Fe~(2+)。晶体结构是由两套无公度的晶格组成,具8C型一维超结构。     

复杂硫盐矿物—辉锑锡铅矿、圆柱锡矿实验研究

作者以硫化物合成实验手段为主,配合X射线粉晶衍射及反光显微镜鉴定、穆斯鲍尔谱价态分析、高温差热分析,并密切结合对天然矿物辉锑锡铅矿、圆柱锡矿的成分分析、矿物共生组合及天然矿物加热实验研究,成功地合成出辉锑锡铅矿和圓柱锡矿,研究了其中元素代换规律,解决了矿物学中这组复杂硫盐矿物长期以来悬而未决的一些问题,得到以下几点关键性突破。 (1)确定了辉锑锡铅矿和圆柱锡矿的化学组成,它们是由不同的硫锑酸根-硫锡酸根(Sn~(4+))以及二价铅、锡、铁组成的硫盐矿物。     

大厂辉锑锡铅矿的(119)Sn和(57)Fe穆斯堡尔谱研究

辉锑锡铅矿是一种复杂的Pb-Sn-Sb硫盐矿物,化学组分变化大,结构复杂。前人对此做了不少工作,但仍未能查明该矿物的晶体结构和晶体化学性质。辉锑锡铅矿含有两种主要的穆斯堡尔元素Sn和Fe,穆谱研究可为该矿物提供重要信息。一些作者曾对产自玻利维亚和苏联的辉锑锡铅矿作过穆谱研究,但在Sn、Fe的价态和谱线等问题上     

Pb—Sn—Fe—Sb—S体系相关系

用抽空石英管法研究以Fe_(0·96) Sb_(2·04) S_(4·12)为投影顶点,8×(PbS-SnS-SnS_2)为投影平面的Pb-Sn-Fe-Sb-S体系的相图表明,由于Pb(?)Sn~(2+)之间互相取代,500℃时辉锑锡铅矿固溶体中Sn~(2+)变化范围(以单位分子式11个金属原子总数为计量)是0—4.8个原子,400℃时则为0—4.0个原子。同时,Sn~(4+)变化范围是1.3—2.3个原子和1.5—2.1个原子。圆柱锡矿固溶体变化范围较小。500℃时Sn~(2+)变化范围是0.4—1.8个原子,400℃时为0.5—1.7。Sn~(+4)变化范围则分别为3.2—4.2个原子和3.3—4.2个原子。变更Fe含量(0.81—1.09)及Sb含量(1.83—2.29)进行的几组合成实验表明,上述两个矿物中Fe、Sb含量变化范围很小,不超过±0.15个原子。辉锑锡铅矿固溶体可与方铅矿、块硫锑铅矿、针硫锑铅矿、硫锡铅矿、硫锡矿、圆柱锡矿等形成平衡结线。而圆柱锡矿不与方铅矿、硫锡矿、硫锡铅矿形成平衡结线,但可与辉锑矿、SnS_2及上述其他矿物形成平衡结线。结合锡的硫化物及氧化物(锡石)热力学稳定场计算表明,在本体系内辉锑锡铅矿在300℃时稳定区的硫活度在lga_(s2)=-20(atm)附近,氧活度小于lga_(o2)=-40(atm),而圆柱锡矿稳定区硫活度大于lga_(s2)=-10(atm)。     

郴县红旗岭锡矿床锡石的成因矿物学研究

郴县红旗岭锡矿床早阶段或产于石英脉中的锡石颜色较深,晚阶段或产于破碎蚀变带中的锡石颜色较浅。本矿床锡石的晶形和晶胞参数特征,反映了它形成于高温、富含挥发组分、中深成—深成的环境。而且锡石存在穆斯堡尔效应(Sn~(119)),Sn~(4+)的I.S.值小,表现为共价键性质,Sn~(2+)的I.S.值相对较大,表现为离子键相对增强;Sn~(4+)的Q.S.值,从早阶段到晚阶段或同一阶段自下而上均有增大趋势。本矿床锡石环带的成分特征,反映出成矿物质从早到晚具有韵律性演化。锡石的Nb、Ta相对含量,指示成矿流体属于弱酸性,In含量反映成矿压力比较小。     

广西某锡矿区锡物相分析方法的研究—硫化物相、水锡石相、硅酸盐相、锡石相的测定

近年来,在锡的物相分析实践中发现,除黝锡矿、辉锑锡铅矿、锡石等矿物存在外,还存在多种含锡的矿物,如含锡的硅酸盐类矿物,含锡的硫化矿物(如磁黄铁矿、黄铁矿等),含锡的氧化矿物(如磁铁矿)以及水锡石类矿物等。如仍按文献的流程进行物相分析,那么难溶硅酸盐类矿物中的锡则与锡石一起计量,而易溶硅酸盐类矿物和其它矿物中的锡均与黝锡矿或胶态锡一起计量,尤其当矽卡岩型矿床中中酸盐类矿物的含锡量比较高时,影响更为严重。     

黝锡矿的119Sn和57Fe穆斯堡尔谱研究

本文收集了我国南方4个产地的黝锡矿样品,使用电子探针、X射线衍射、~(119)Sn、~(57)Fe穆斯堡尔谱等测试方法测试。X射线衍射结果,黝锡矿的晶胞参数为:a=5.4531(5)?,c=10.7470(7)?,四方晶系,空间群I42m。4个不同产地的黝锡矿的Sn、Fe穆斯堡尔谱测量表明:锡的I·S值为1.34—1.49mm/s,Q·S值为0.36—0.50mm/s,为四面体的Sn~(4+);铁的I·S值为0.588—0.596mm/s,Q·S值为2.900—2.911mm/s,为四面体的Fe~(2+)。Sn、Fe离子仅占据一种结晶学位置。这些黝锡矿富Zn,Zn以类质同象置换Fe。     

Fe-Sn-Sb-S体系内四元相无铅辉锑锡铅矿、无铅圆柱锡矿及铁锑斜方硫锡矿的实验研究

作者在辉锑锡铅矿-硫锑锡铁铅矿-potosiite以及圆柱锡矿两个固溶体系列的实验研究基础上,合成出铅全部被二价锡取代生成的无铅端员——无铅辉锑锡铅矿和无铅圆柱锡矿。并进一步在Fe-Sn-Sb-S体系内确定了第三个相——含铁、锑的斜方硫锡矿固溶体相的存在。无铅辉锑锡铅矿和无铅圆柱锡矿作为纯相只能在高温下被合成。铁锑斜方硫锡矿虽然也可以在600℃被合成,但在500℃以下,它在更广泛的范围内存在。文章也涉及到无铅的SnS-SnS_2-FeSb_2S_4假三元系内相的关系,即600℃时所观察到的随四价锡增加而依次出现的相及相的共生。     

对铅圆柱锡矿的重新认识

铅圆柱锡矿(potosiite)是1981年在玻利维亚的锡矿床中发现的,沃尔夫等人测定了它的化学成份和X射线粉晶衍射数据,作为新矿物列入JCPDS卡片。近年来作者在工作中发现,实际上该矿物旱在1972年就被我国地质工作者在广西大厂的锡石硫化物矿床中采集,由于该矿物的物理性质与辉锑锡铅矿的物理性质极为相似,以及限于当时的实验条件而误定名为辉锑锡铅矿。为便于今后的工作,作者认为育必要对铅圆柱锡矿和辉锑锡铅矿进行重新认识。     

Determination of the Tin Stable Isotopic Composition in Tin‐bearing Metals and Minerals by MC‐ICP‐MS

This study uses MC‐ICP‐MS for the precise analysis of the stable tin isotopic composition in ore minerals of tin (cassiterite, stannite), tin metal and tin bronze. The ultimate goal is to determine the provenance of tin in ancient metal objects. We document the isotope compositions of reference materials and compare the precision of different isotope ratios and the accuracy of different procedures of mass fractionation correction. These data represent a base with which isotopic data of future studies can be directly compared. The isotopic composition of cassiterite and stannite can be determined after reduction to tin metal and bronze, respectively. Both metals readily dissolve in HCl, but while the solutions of tin metal can be directly measured, the bronze solutions must be purified with an anion exchanger. The correction of the mass bias is best performed with an internal Sb standard and an empirical regression method. A series of Sn isotope determinations on commercially available mono‐element Sn solutions as well as reference bronze materials and tin minerals show fractionations ranging from about ?0.09‰ to 0.05‰/amu. The combined analytical uncertainty (2s) was determined by replicate dissolutions of reference materials of bronze (BAM 211, IARM‐91D) and averages at about 0.005‰/amu.     

异性石中平面四配位Fe^2＋的穆斯堡尔谱研究

除硅铁钡矿之处，性石是迄今仅知的另一种含有平面四配位Ｆｅ＾２＋的矿物，异性石晶体样品为玫瑰色，透明，有油脂光泽，取自一花岗岩标本，异性石中平面四配位Ｆｅ＾２＋的穆斯堡尔参数：化学位移＝０．７８５（ｍｍ／ｓ）（相对天然铁），四极矩分裂＝０．４１９（ｍｍ／ｓ），明显地低于大多数硅酸矿物中的Ｆｅ＾２＋，但和硅铁钡矿的Ｆｅ＾２＋十分相近，本文对硅酸盐矿物Ｆｅ＾２＋的穆斯堡尔参数与配位数之间的关系做了讨论。     

Mutual Pb2+/Sn2+ substitution in sulfosalts

Summary In naturally occurring sulfides and sulfosalts, the elements tin and lead can substitute for each other and form solid solution series. The best known example is the montesite series between teallite and herzenbergite. Within a coordinated research program including ore microscopy, X-ray and microprobe studies, mineral syntheses and Mössbauer spectroscopy, other lead sulfosalts were discovered which show considerable solid solution series.Natural tin-bearing jamesonites which have been recently discovered have also been confirmed experimentally.The present work reveales a broad solid solution field for franckeite ranging from Pb-rich potosiite to Sn-rich incaite. The well-established silver-free franckeite formula exhibits an ideal composition of(Pb, Sn) ₆ ²⁺ Fe²⁺ Sn ₂ ⁴⁺ Sb ₂ ³⁺ S ₁₄ ^2– . Valencies of the Fe, Sn, and Sb in franckeite shown in this formula have been confirmed by Mössbauer spectroscopy. Frequently observed trace amounts of Ag, Zn, Ge, and In are not essential in the structure.Numerous microprobe analyses of cylindrites indicate that they form a restricted solid solution series with slight Pb/Sn²⁺ variations. Cylindrite forms at increased sulfur fugacity. Experiments and microprobe analyses on ores demonstrate the direct replacement of tin-rich franckeite or incaite by pseudomorphic lamellae of cylindrite during controlled sulfdization but no characteristic cylinders were observed. In the replacement reaction most or all of the bivalent tin was oxidized to quadrivalent tin to form cylindrite Pb₄FeSn₄Sb₂S₁₆.Contribution to the Ore Mineralogy Symposium (IMA/COM) at the 14th General Meeting of the International Mineralogical Association, at Stanford, California, in July, 1986.     

The effect of temperature of reaction on the extraction of tin from calc-silicate rocks by NH4I volatilisation

Extraction of lattice-bound tin from calc-silicate minerals in the determination of tin in skarn rocks by NH₄I volatilisation is reported. This analytical technique has previously been regarded as specific for cassiterite and stannite. Although the NH₄I volatilisation reaction does not decompose calc-silicate minerals there is an increase in the yield of NH₄I-volatilised tin when the volatilisation temperature is raised above 500°C. The temperature effect is only observed for whole-rock samples and the type of behaviour appears related to the mineralogy of the rock. For instance, magnetite-bearing rocks have a different temperature yield curve to pyrrhotite-bearing rocks. When concentrates of single minerals are reacted with NH₄I this temperature dependence is not observed, although there is an increase in tin yield with decreasing grainsize.     

An Experimental Study on Three Quaternary Phases in the Fe-Sn-Sb-S System: Pb-Free Franckeite, Pb-Free Cylindrite and (Fe, Sb)-Ottemannite s.s.

Experimental studies on the two solid solutions franckeite s.s. and cylindrite s.s. yielded among others thePb-free endmembers of franckeite and cylindrite respectively. In these endmembers the lead content of the twomineral phases are completely substituted by bivalent tin. A third phase, ottemannite s.s. with (Fe. Sb)-bearingcompositions, was further identified in the Pb-free 4-component system Fe-Sn-Sb-S. Pb-free franckeite andcylindrite could only be synthesized as homogeneous phases at high temperatures. The ottemannite s.s. was ob-tained at 600℃ but an extensive existing range was also confirmed at temperatures below 500℃. The phase relations were discussed in the pseudoternary subsystem SnS-SnS_2-FeSb_2S_4. The following se-quence of Pb-free phases and phase assemblages were observed under increasing Sn~(4+) content at 600℃:herzenhergite (SnS)+franckeite, franckeite, franckeite+cylindrite, cylindrite, cylindrite+(Fe, Sb)-ottemannite.(Fe, Sb)-ottemannite. (Fe. Sb)-ottemannite+berndtite (SnS_2). The assemblage cylindrite+berndtite was identi-fied in synthetic systems involving Pb. The phase Fe. Sb-ottemannite s.s. appears to be stable only under Pb-de-ficient and high sulfur fugacity conditions.     

Indium Enrichment in the Meng'entaolegai Ag-Pb-Zn Deposit, Inner Mongolia, China

Abstract. The Meng'entaolegai In-rich Ag-Pb-Zn deposit is located in the eastern part of Inner Mongolia. It is one of the In-richest deposits in China. Large amounts of quartz and sulfide minerals constitute a hydrothermal quartz-sulfide vein deposit within a Hercynian acidic granite massif, which occupies an area of about 400 km². Thirty-six orebodies, controlled strictly by the E-W trend faults, are found in the orefield of 6 km in length from east to west and 200 to 1,000 m in width from south to north. The ore minerals are mainly galena, sphalerite and pyrite, and subordinate chalcopyrite, arsenopyrite, cassiterite and stannite with many Ag-minerals. The gangue minerals are mainly quartz, calcite, sericite and chlorite. Economic components of the deposit are dominated by Pb andZn (reserves of Pb and Zn are 0.17 Mt and 0.37 Mt, and their grades are 1 % and 2.3 %, respectively), with Ag, Sn, In and Cd (1,800 t Ag, >2,000 t Sn, >500 t In and 1,800 t Cd) as by-products. Indium is highly enriched in ores and its contents are 9 to 295 ppm in ores and 85 to 2,660 ppm in sphalerite. Analytical results show that the ore-forming fluid of this deposit contains 0.8–3.5 ppm In and 4–36 ppm Sn, and the two elements show a very good positive correlation with a correlation coefficient of 0.8672, while the correlation between In and Zn in the ore-forming fluids, with a correlation coefficient of 0.5723, is not as good as that between In and Sn. This indicates that indium has an affinity with tin in the ore-forming fluids. The authors think that this is probably the main reason why those In-rich deposits spread over the world are simultaneously enriched in tin.     

柿竹园矿床大理岩型锡矿石工艺矿物学研究

大理岩型锡矿石产于燕山早、中期千里山花岗岩与中、上泥盆统灰岩的外接触带。矿石呈细脉、网脉浸染状,锡矿物有:锡石、黄锡矿,富钛尼日利亚石、尼日利亚石和木锡矿,脉石矿物绿帘石、石榴石、电气石、萤石、方解石及磁黄铁矿等亦含锡,锡主要呈锡的浊立矿物存在,占总锡量的89.78％,其中锡石锡占总锡量的80.01％,其次有呈类质同象形式存在的锡,在绿帘石、石榴石、电气石等矿物中以Sn~(4+)取代Fe~(3+),这类锡占总量的8.33％。工艺矿物学研究表明,该类锡矿石以“贫”、“细”、“杂”为特征。锡不仅十分分散,而且品位偏低,矿石矿物组合及镶嵌关系复杂、相互包裹,紧密连生;锡矿物粒度微细,粒径一般为0.2～0.01mm,部分为<0.0l～0.002mm,是一种难选的锡矿石类型。通过锡的回收试验,采用选冶联合工艺流程,预测锡的最佳回收率可达50％以上。     

Study on the Cu–As–Sb–Ag–Bi–Pb–Te Sulfosalt Minerals from the Hydrothermal System of Southwestern Hokkaido,Japan

Shin‐Otoyo, Suttsu, Teine, Date, Chitose, and Koryu are sites rich in precious and base metal Miocene–Pleistocene epithermal deposits, and located in southwestern Hokkaido, Japan. The deposits are predominantly hosted by the Green Tuff Formation of Middle Miocene age. Ore petrographic study of these deposits shows the occurrence of variable quantities of Cu–As–Sb–Ag–Bi–Pb–Te sulfosalt minerals. Determination of mineralogical and chemical compositions of the sulfosalt minerals was undertaken to elucidate the time and spatial changes of the sulfide‐sulfosalt minerals. Various types of sulfosalt minerals identified from gold–silver and base metal quartz–sulfide veins represented some sulfosalt mineralization phases, such as the Cu–Fe–Sn–S phase of mawsonite and stannite; Cu–(As,Sb)–S phase of tetrahedrite–tennantite and luzonite–famatinite series minerals; (Cu,Ag)–Bi–Pb–S phase of emplectite, pavonite, friedrichite, aikinite, and lillianite–gustavite series minerals; (Ag,Cu)–(As,Sb)–S phase of proustite–pyrargyrite and pearceite–polybasite series minerals; and Bi–Te–S phase of tetradymite and kawazulite minerals. There are some trends in the paragenetic sequence of sulfosalt mineralization in southwestern Hokkaido (in complete or partial) as follows: sulfide → Cu–Fe–Sn–S → (Cu,Ag)–Bi–Pb–S → (Bi–Te–S) → Cu–(As,Sb)–S → ([Ag,Cu]–[As,Sb]–S). The formation of sulfosalt minerals is characterized by the introduction of some elements such as Sn, Bi, and Te at an earlier stage and an increase or decrease of some elements such as As and Sb, followed by the introduction of Ag at the later stage of ore mineral paragenesis sequence. Mineral composition of the Chitose and Koryu deposits are slightly different from those of Shin‐Otoyo, Suttsu, Teine, and Date due to their lack of Sn (tin) and Bi (bismuth) mineralization. The variable concentrations and relationships are not simply with redistributed trace elements from the original sulfide minerals of chalcopyrite, pyrite, galena, and sphalerite. Some heavier elements were also introduced during the replacement reaction, which is consistent with the occurrence of their associated minerals.     

The Tiger Sulfide Chimney,Yonaguni Knoll IV Hydrothermal Field,Southern Okinawa Trough,Japan: The First Reported Occurrence of Pt–Cu–Fe‐Bearing Bismuthinite and Sn‐Bearing Chalcopyrite in an Active Seafloor Hydrothermal System

A sulfide chimney ore sampled from the flank of the active Tiger vent area in the Yonaguni Knoll IV hydrothermal field, south Okinawa trough, consists of anhydrite, pyrite, sphalerite, galena, chalcopyrite and bismuthinite. Electron microprobe analysis indicates that the chalcopyrite contains up to 2.4 wt% Sn, whereas bismuthinite contains up to 1.7 wt% Pt, 0.8 wt% Cu and 0.5 wt% Fe. The Sn‐rich chalcopyrite and Pt–Cu–Fe‐bearing bismuthinite are the first reported occurrence of such minerals in an active submarine hydrothermal system. The results confirm that Sn enters the chalcopyrite as a solid solution towards stannite by the coupled substitution of Sn⁴⁺Fe²⁺ for Fe³⁺Fe³⁺, whereas Pt, Cu and Fe enter the bismuthinite structure as a solid solution during rapid nucleation. The fluid inclusions homogenization temperatures in anhydrite (220–310°C) and measured end‐member temperature of the vent fluids on‐site (325°C) indicate that Sn‐bearing chalcopyrite and Pt–Cu–Fe‐bearing bismuthinite express the original composition of the minerals that precipitated as metastable phases at a temperature above 300°C. The result observed in this study implies that sulfides in ancient volcanogenic massive sulfide deposits have similar trace element distribution during nucleation but it is remobilised during diagenesis, metamorphism or supergene enrichment processes.