pH值和氧化剂对硫化锑氧化溶解的影响机制

矿山开采活动影响下辉锑矿的氧化溶解是影响岩-土-水环境介质中锑的迁移转化及其环境效应的重要过程。目前对于辉锑矿溶解的研究主要关注动力学特征,对于它氧化溶解的途径、环境因素的影响、锑的释放规律等重要问题的认识还不明确。为探究碳酸盐岩矿区地下水中锑释放过程,选取重要环境因素pH值和Fe(Ⅲ),采用单因素控制条件下的批实验方法,精细刻画避光条件下辉锑矿(Sb_2S_3)氧化溶解速率及Sb和S氧化产物的组成特征。研究结果表明,Sb_2S_3的氧化溶解是一个产酸的过程,Sb和S的释放速率、途径和产物特征受pH值和Fe(Ⅲ)的显著影响。Sb_2S_3的氧化溶解速率由快变慢后趋于平衡,初始反应速率的量级为10~(-8) mol/(m~2·s),平衡反应速率的量级为10~(-10) mol/(m~2·s)。Sb的释放氧化速率随pH值的增加而增加,强碱条件下最有利于Sb的释放和氧化。强酸条件下,H_2S、SO_2气体逸出和S(0)的沉淀促进了Sb_2S_3的溶解,Sb(Ⅲ)和S(0)为主要产物。中性条件下,溶解形成的HS~-经逐步氧化生成SO~(2-)_4和少量S_2O~(2-)_3,Sb(Ⅲ)和Sb(V)含量相近。强碱条件下,SbS~(3-)_3和S~-_x的生成显著提升了Sb_2S_3的氧化溶解速率,Sb(V)和S_2O~(2-)_3是主要产物。Fe(Ⅲ)单独氧化作用时,Sb(V)和S(0)是主要产物,锑释放的表观速率无显著提升,可能与SbOCl和S(0)的生成有关。研究表明,O_2能够协同Fe(Ⅲ)氧化Sb_2S_3,但以Fe(Ⅲ)的作用为主导。本研究揭示了Sb_2S_3在不同pH值及氧化剂条件下氧化溶解的产物组成特征,提出了不同环境因素影响下的氧化溶解途径,证明碳酸盐岩天然缓冲地层更有利于锑的释放与氧化,岩溶地下水中锑诱发的环境效应会更为严重。     

Tl—In—S三元系的实验研究

作者通过T1—In-S三元系实验研究,在300℃等温面上发现4个三元固溶体相和2个三元相。4个三元固溶体相的成分变化范围分别是:(Ⅰ)T1_(2C)InS_(16)-T1_(40)In_3S_(33);(Ⅱ)T1_4InS_5—T1_4InS_4;(Ⅲ)T1_8In_2S_7—T1_(15)In_3S_(11)和(Ⅳ)T1_2In_2S_5。2个三元相的成分分别是T1_3InS_3和T1_2In_2S_3。这些相之间的关系清楚地示于T1-In-S相图中。此外,在600℃时合成了三元相T1In_2S_3,并对前人的实验研究进行了补充和修正。     

我国首次发现的镉银黝铜矿

我们发现的镉银黝铜矿产于青海省锡铁山铅锌矿床氧化带中,颗粒细微,最大颗粒为30μm,一般为2—5μm,平均颗粒为3μm。4个颗粒的电子探针分析结果(％)是:Ag15.582—17.503,平均16.863; Cu22.419—23.555,平均22.802;Cd9.042—11.966,平均10.748;Zn0.175—1.007,平均0.516;Fe0.050—1.528,平均0.426;Sb24.970—26.247,平均25.691;As0.871—1.216,平均0.988;S20.960—21.823,平均21.507。根据平均化学成分计算的分子式为;(Cu_(6.95)Ag_(3.03))_(9.98)(Cd_(1.86)Zn_(0.15)Fe_(0.15))_(2.15)(Sb_(4.09)As_(0.25))_(4.34)S_(13),简化式为Cu_(10)Cd_2Sb_4S_(13)。     

我国雄黄雌黄矿地质概况

<正> 雄黄和雌黄是一种含砷的硫化物矿物,其分子式前者为AsS,含砷70.1%;后者为As_2S_3,含砷60.98%。矿床属低温热液型,多以充填方式产于砂岩、页岩和石灰岩的裂隙中,呈脉状、囊状分布。矿石矿物主要是雄黄和雌黄,有时亦与毒砂、胶黄铁矿、白铁矿、辉锑矿、辰砂、方铅矿等共生,脉石矿物为石英、玉髓、方解石、白云石等。一般规定矿石的边界品位As 为3%,最低工业品位As 为5%。矿石中除As 外常含有Ga、Tl、Se、Au、Sb、Hg 等可综合利用的有益元素。国内目前已知的雄黄-雌黄矿床有9个,分布于中南区和西南区7省,总储量不到×万吨     

陕西洛南发现含碲黝铜矿

陕西洛南发现的含碲黝铜矿产于含碲金石英脉中。呈不规则粒状,粒径0.1—0.4mm。实测维氏硬度为227kg/mm~2,相当摩氏硬度4.1。400—700nm波段反射率色散值为35.10—24.13％。颜色指数:R=24.87;x=0.3283;y=0.3130,λd=489;Pe=0.075。四个颗粒电子探针分析结果(％):Cu 41.70—42.39,平均42.133;Zn 5.09—5.59,平均5.345;Fe 0.02—0.30,平均0.145;Ag 0.00—0.10,平均0.033;Sb 14.93—16.79,平均16.023;As 6.09—7.57,平均6.655;S 23.91—24.55,平均24.228;Te 4.93—6.46平均5.645。根据分析结果的平均值计算矿物化学式:(Cu_(10.0593)Ag_(0.0052)_(10.0645)(Zn_(1.3353)Cu_(0.6232)Fe_(0.0415)_(2.00)(Sb_(2.1319)As_(1.4398)_(3.5717)(S_(12.2841)Te_(0.7159)_(13.00),简化式Cu_(10)Zn_2(Sb,As)_4(S,Te)_(13)     

缓冲期碳酸盐型尾矿重金属释放机制——柱淋滤实验研究

碳酸盐型尾矿在缓冲期/中性矿山废水(NMD)释放期的重金属污染问题易被忽视。本文以广西大厂锡石-硫化物尾矿作为研究对象,采用柱淋滤实验方法,探讨碳酸盐型尾矿在缓冲期重金属的释放机制,为此类型尾矿重金属污染的防治提供依据。实验结果表明,大厂尾矿在缓冲期(约7年,pH值为6. 6～8. 0)存在Sb、Zn、Cd、As(Pb)释放污染问题。在尾矿堆放初期(0. 5年,pH值由7. 6降至7. 2),Zn、Sb、Cd快速、大量释出;中期(0. 5～2. 5年,pH值由7. 2波动升高至8. 0),Sb较平稳释出;后期(2. 5～7年,pH值变化范围为8. 0～6. 6,呈降低趋势),受气温及pH值影响,As、Sb(Pb)呈波动或间歇振荡释出,即在夏季高温、pH值较高时,释出元素浓度较高,反之,在冬季低温、pH值较低时,释出元素浓度较低。重金属的释放与尾矿中硫化物的氧化程度高低及氧化先后顺序有关。这些矿物的氧化顺序大致为:闪锌矿(Zn、Cd)、辉锑锡铅矿(Sb)→脆硫锑铅矿(Sb)→毒砂(As)、方铅矿(Pb)。因此,对于(广西大厂)碳酸盐型尾矿在缓冲期的重金属污染应分阶段、季节(夏季),采取有针对性的防治措施;在缓冲期(7年)后应注意尾矿酸性矿山废水(AMD)+重金属(如As、Sb)复合污染的防治。     

结构矿物学的新成果(续)

七、Pd_5(Sb,As)_2矿物的晶体化学近年来发现了不少铂族元素新矿物,其中成分为Pd_5(Sb,As)_2的为数甚多。这些矿物成分复杂,结构都未测定,因此对它们的看法也比较混乱,急待理出一个头绪来,以指导进一步的工作。Pd_5(Sb,As)_2矿物的成分是可变的,它们的分子式按A．Desborough等的意见,可写成通式:     

亚铁氰化钾提高原子荧光法测定砷锑铋的抗干扰能力

本文提出抗坏血酸-K_4[Fe(CN)_6]-硫脲体系,氢化物原子荧光法测定地质样品中痕量As、Sb和Bi。用K_4[Fe(CN)_6]消除干扰元素,可大大提高共存元素允许量。方法检出限(μg/ml)As 0.10,Sb 0.04,Bi 0.05;RSD均小于6％。 1 仪器与分析条件 XDY-1型原子荧光光度计(北京地质仪器厂生产)。输入功率As 20～35W、Sb 20～30W、Bi 30～40W,反射功率均调至最小,氩载气流量1L/min,负高压300～350V,炉温为900℃。7g/L KBH_4加入量是5ml。     

Tl—Ga—S三元系的合成实验研究

作者系统地进行了Tl—Ga—S三元系的合成实验研究。在300℃等温面上,发现了四个新相,Tl_4GaS_5为三元纯相,Ⅰ、Ⅱ、Ⅲ为固溶体相区,其成分变化范围分别是:(Ⅰ)Tl_(20)GaS_(16)—Tl_(20)Ga_2S_(17),(Ⅱ)Tl_(10)Ga_6S_(17)—Tl_5Ga_3S_7,(Ⅲ)Tl_2Ga_2S_5—TlGaS_2。此外,在630—900℃还存在一个成分为TlGa_5S_8—Tl_2Ga_(10)S_(11)的固溶体相。对这些新相均进行了X-射线粉晶衍射、光性及某些物性测试。X-射线粉晶衍射数据已进行了指标化。     

辉锑矿分析

辉锑矿Sb_2S_3,主要成分为Sb(71％),S(28％),伴生有微量As、Cu、Pb、Zn、Sn、Bi、Ag等元素。 锑的大量存在及锑化物在酸度低时容易水解,常给其他项目的分析带来困难,一般分离手续麻烦。本文采用在石墨坩埚内以盐酸-氢溴酸分解样品并挥发除锑、碱熔后制备成5％盐酸溶液。可测定铜、铅、锌、银、硅、铁、铝,钛、钙、镁、锰等元素。单独     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)     

GEOCHEMISTRY

正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861