Sulfur Determination in Geological Samples Based on Coupled Analytical Techniques: Electric Furnace-IC and TGA-EGA     

Maria F. Gazulla  Maria P. Gómez  Mónica Orduña  Eulalia Zumaquero  Sonia Vicente 《Geostandards and Geoanalytical Research》2009,33(1):71-84

A study has been undertaken to determine sulfur in geological samples by coupled analytical techniques. Two measurement methods have been developed: one using an electric furnace coupled to an ion chromatograph (electric furnace-IC) and another using infrared (IR) and quadrupole mass spectrometry (QMS) for evolved gas analysis (EGA) coupled with a thermogravimetric analyser (TGA). In the electric furnace-IC method, measurement was performed without any sample pre-treatment. The measurement conditions were optimised by varying sample quantity, type of catalyst (WO₃, Cu, W and V₂O₅) and sample/catalyst ratio, and the detection limit was 10 μg g⁻¹. Sulfur ores decompose at different temperatures. However, TGA-EGA allowed identification of the different forms of sulfur in the sample, even when they were found in very low concentrations, because the sulfur was continuously analysed. The developed chromatographic method allowed simultaneous analysis of several sample components, such as S, Cl and F, with a low detection limit. The method was much faster and more specific than the methods described in the literature. The results of the sulfur determination had low scatter, possibly because the samples underwent little handling during analysis: the operator only weighed and placed the sample in the furnace, the rest of the measurement process was fully automated. The results obtained by both the developed methods have been validated by using reference materials and comparison with combustion-IR spectroscopy, a standard method for determining total sulfur in a sample.  相似文献   

On the scavenging of SO2 by cloud and raindrops: II. An experimental study of SO2 absorption and desorption for water drops in air     

C. J. Walcek  H. R. Pruppacher  J. H. Topalian  S. K. Mitra 《Journal of Atmospheric Chemistry》1983,1(3):291-306

For the purpose of testing our previously described theory of SO₂ scavenging a laboratory investigation was carried out in the UCLA 33 m long rainshaft. Drops with radii between 250 and 2500 m were allowed to come to terminal velocity, after which they passed through a chamber of variable length filled with various SO₂ concentrations in air. After falling through a gas separating chamber consisting of a fluorocarbon gas the drops were collected and analyzed for their total S content in order to determine the rate of SO ₂ absorption.The SO₂ concentration in air studied ranged between 1 and 60% (v). Such relatively large concentrations were necessary due to the short times the drops were exposed to SO₂ in the present setup. The present experimental results were therefore not used to simulate atmospheric conditions but rather to test our previously derived theory which is applicable to any laboratory or atmospheric condition. Comparison of our studies with the results from our theory applied to our laboratory conditions led to predicted values for the S concentration in the drops which agreed well with those observed if the drops had radii smaller than 500 m. In order to obtain agreement between predicted and observed S concentrations in larger drops, an empirically derived eddy diffusivity for SO₂ in water had to be included in the theory to take into account the effect of turbulent mixing inside such large drops.In a subsequent set of experiments, drops initially saturated with S (IV) were allowed to fall through S-free air to determine the rate of SO ₂ desorption. The results of these studies also agreed well with the results of our theoretical model, thus justifying the reversibility assumption made in our theoretical models.In a final set of experiments, the effects of oxidation on SO₂ absorption was studied by means of drops containing various amounts of H₂O₂. For comparable exposure times to SO₂, the S concentration in drops with H₂O₂ was found to be up to 10 times higher than the concentration in drops in which no oxidation occurred.  相似文献   

三次拟合计算法测定土壤样品中的硫含量     

周小林  朱志雄 《贵州地质》2012,29(1):68-71

本方法采用三次拟合计算法处理土壤样品中硫含量的测试结果。试样采用传统的燃烧碘量法进行处理,在结果计算中使用三次拟合法处理测试结果,取得令人满意的效果。本方法的精密度为1.54%5.38%,方法检出限（3S）：0.005%,较好的满足土壤样品中硫的测试要求。  相似文献   

Fluid Inclusions and Hydrogen,Oxygen, Sulfur Isotopes of Nuri Cu‐W‐Mo Deposit in the Southern Gangdese,Tibet     

Lei CHEN  Kezhang QIN  Jinxiang LI  Bo XIAO  Guangming LI  Junxing ZHAO  Xin FAN 《Resource Geology》2012,62(1):42-62

The Nuri Cu‐W‐Mo deposit is located in the southern subzone of the Cenozoic Gangdese Cu‐Mo metallogenic belt. The intrusive rocks exposed in the Nuri ore district consist of quartz diorite, granodiorite, monzogranite, granite porphyry, quartz diorite porphyrite and granodiorite porphyry, all of which intrude in the Cretaceous strata of the Bima Group. Owing to the intense metasomatism and hydrothermal alteration, carbonate rocks of the Bima Group form stratiform skarn and hornfels. The mineralization at the Nuri deposit is dominated by skarn, quartz vein and porphyry type. Ore minerals are chalcopyrite, pyrite, molybdenite, scheelite, bornite and tetrahedrite, etc. The oxidized orebodies contain malachite and covellite on the surface. The mineralization of the Nuri deposit is divided into skarn stage, retrograde stage, oxide stage, quartz‐polymetallic sulfide stage and quartz‐carbonate stage. Detailed petrographic observation on the fluid inclusions in garnet, scheelite and quartz from the different stages shows that there are four types of primary fluid inclusions: two‐phase aqueous inclusions, daughter mineral‐bearing multiphase inclusions, CO₂‐rich inclusions and single‐phase inclusions. The homogenization temperature of the fluid inclusions are 280°C–386°C (skarn stage), 200°C–340°C (oxide stage), 140°C–375°C (quartz‐polymetallic sulfide stage) and 160°C–280°C (quartz‐carbonate stage), showing a temperature decreasing trend from the skarn stage to the quartz‐carbonate stage. The salinity of the corresponding stages are 2.9%–49.7 wt% (NaCl) equiv., 2.1%–7.2 wt% (NaCl) equiv._, 2.6%–55.8 wt% (NaCl) equiv. and 1.2%–15.3 wt% (NaCl) equiv., respectively. The analyses of CO₂‐rich inclusions suggest that the ore‐forming pressures are 22.1 M Pa–50.4 M Pa, corresponding to the depth of 0.9 km–2.2 km. The Laser Raman spectrum of the inclusions shows the fluid compositions are dominated in H₂O, with some CO₂ and very little CH₄, N₂, etc. δD values of garnet are between ?114.4‰ and ?108.7‰ and δ¹⁸O_H2O between 5.9‰ and 6.7‰; δD of scheelite range from ?103.2‰ to ?101.29‰ and δ¹⁸O_H2O values between 2.17‰ and 4.09‰; δD of quartz between ?110.2‰ and ?92.5‰ and δ¹⁸O_H2O between ?3.5‰ and 4.3‰. The results indicate that the fluid came from a deep magmatic hydrothermal system, and the proportion of meteoric water increased during the migration of original fluid. The δ³⁴S values of sulfides, concentrated in a rage between ?0.32‰ to 2.5‰, show that the sulfur has a homogeneous source with characteristics of magmatic sulfur. The characters of fluid inclusions, combined with hydrogen‐oxygen and sulfur isotopes data, show that the ore‐forming fluids of the Nuri deposit formed by a relatively high temperature, high salinity fluid originated from magma, which mixed with low temperature, low salinity meteoric water during the evolution. The fluid flow through wall carbonate rocks resulted in the formation of layered skarn and generated CO₂ or other gases. During the reaction, the ore‐forming fluid boiled and produced fractures when the pressure exceeded the overburden pressure. Themeteoric water mixed with the ore‐forming fluid along the fractures. The boiling changed the pressure and temperature, oxygen fugacity, physical and chemical conditions of the whole mineralization system. The escape of CO₂ from the fluid by boiling resulted in scheelite precipitation. The fluid mixing and boiling reduced the solubility of metal sulfides and led the precipitation of chalcopyrite, molybdenite, pyrite and other sulfide.  相似文献   

赣南崇义淘锡坑钨矿床氢、氧、硫同位素地球化学研究   总被引：11，自引：2，他引：9  

宋生琼  胡瑞忠  毕献武  魏文凤  石少华 《矿床地质》2011,30(1):1-10

赣南崇义县淘锡坑钨矿位于南岭东西向构造带东段与武夷山NE-NNE向构造带南段的复合部位,属于以石英脉型黑钨矿为主的钨多金属矿床.文章通过氧、氧、硫同位素地球化学特征的研究,探讨了淘锡坑钨矿成矿流体的来源及演化.研究结果显示:δD值介于-77‰～-45‰之间;石英矿物的δ18O值介于+7.3‰～+12.2‰之间,计算给出...  相似文献   

Sulfur Isotopes of Framboidal Pyrite in the Permian-Triassic Boundary Clay at Meishan Section     

ZHANG Jun  LIANG Handong  HE Xiaoqing  YANG Ye  CHEN Baohua 《《地质学报》英文版》2011,85(3):694-701

Pyrite framboids were found in the Permian-Triassic boundary at Meishan Section, while their sulfur isotopes were determined. The majority of framboids is less than 5 μm in diameter, with some large-sized framboids. Also, euhedral gypsums were observed in the boundary clay. The authors suppose that most of the pyrite framboids formed just below the redox boundary and stopped growing after entering the lower water column. The result indicates that it was probably lower dysoxia condition in the temporal ocean. Moreover, the authors also presume that some pyrite was oxidated to sulfates accompanying the fluctuation of redox condition, which would probably be the origin of the negative sulfur isotopes of gypsum and CAS reported before. In addition, sulfur isotope of framboidal pyrite suggests that sulfur is originated from bacterial sulfate reduction in anoxic condition. Therefore, this study confirms that the ocean was widely anoxic during the Permian-Triassic transitional period. However, the redox condition in temporal ocean was probably not stable, with short-term fluctuations.  相似文献   

贵州纳雍水东铅锌矿矿床地球化学特征   总被引：2，自引：0，他引：2  

吴波  陈国勇  陶平  谯文浪 《贵州地质》2011,28(2):108-113

对贵州纳雍水东乡洗米沟、坟山脚一带灯影组地层中铅锌矿石采样,进行镜下观察和全岩主量、微量元素、稀土元素以及硫同位素地球化学研究。微量元素研究表明,矿床中N i、Mo、As、Sb等成矿元素富集明显,Sr、Ba、V等元素强烈亏损,认为早寒武世热水对铅锌矿源层进行了淋滤和改造;稀土元素研究表明,铅锌矿石稀土配分曲线向右倾斜,...  相似文献   

滇西北衙金多金属矿床成矿地球化学特征   总被引：10，自引：0，他引：10  

肖晓牛 《地质与勘探》2011,47(2):170-179

北衙金多金属矿床是金沙江-哀牢山-红河断裂带与新生代富碱斑岩有关的斑岩型矿床之一.本文重点提供了流体包裹体中稀土微量元素和矿石S、Pb同位素分析结果,并对成矿流体及成矿物质来源等问题进行了讨论.研究表明,本区流体包裹体稀土总量较低,∑REE介于5.19×10-6～9.0×10-6之间,反映轻重稀土分馏程度的∑LREE/...  相似文献   

硫化物及硫酸盐中硫同位素制样装置及其反应器研制     

李振涛  刘汉彬  金贵善  李军杰  钟芳文 《国外铀金地质》2011,(1):52-54

研制了一种新型硫化物及硫酸盐中硫同位素制样装置及其反应器。实验证明,采用该装置及其反应器制样具有真空度好、使用方便、无污染、制样效率高和成本低等优点。所生成的二氧化硫具有纯度高,分析结果准确、可靠等特点,完全能满足硫化物和硫酸盐中硫同位素分析测试的制样要求。  相似文献   

川东北地区海相烃源岩中单质硫的定性与定量分析     

张中宁  刘文汇  夏燕青  腾格尔  王作栋  高波  张殿伟  邱军利 《矿物岩石》2011,31(3)

利用定性与定量分析手段,研究了川东北地区各类海相烃源岩中的单质硫及其地球化学特征。定性分析表明,该区海相烃源岩中的单质硫具有八硫环状结构和六硫状环结构两种晶体构型,由S8和S6两种同素异形体组成,其中S8具有相对较高的丰度。定量分析表明,该区海相烃源岩中的单质硫含量为0.91×10-6～375.88×10-6,具有很宽的分布范围,并且随着烃源岩分布区域、地层时代以及岩性的不同而发生明显变化,表现出强烈的非均质性分布特征。该区海相烃源岩中单质硫含量与有机碳含量之间存在正相关关系,说明单质硫主要发育在富有机质沉积的层段中。通过单质硫含量与总硫含量对比分析,间接证明了川东北地区各类海相烃源岩中赋存有丰富的有机含硫化合物。  相似文献