橄榄石水溶性与含铁量相关性的实验研究   总被引：3，自引：2，他引：3  

赵永红 Ginsb.  S 等 《岩石学报》2001,17(1):123-128

本文首次报导了含铁量不同的橄榄石单晶在不同温压条件下水溶性的试验研究结果。橄榄石单晶试件在300MPa静水压和1000℃至1300℃的温度条件下进行热压，每隔50℃进行一组试验，氧逸度被控制在Ni/NiO水平上。对热压后试件的抛光无包裹体区域做了显微红外光谱分析，红外光束平行于试件的[010]方向，最小直径为15－25μm。分析结果表明，在实验温压范围内，橄榄石中的水含量随铁含量的增加而增加。对于同样铁含量的橄榄石，则随湿度的增加，橄榄石的水含量也增加。最后，本文就实验结果对地幔动力学过程的启示进行了简单的讨论。  相似文献   

The solubility of a metallic mineral with other coexisting minerals and the ore-forming processes of metallic sulfides     

岑况  於崇文 《中国科学D辑(英文版)》2001,44(4):289-297

Most metallic minerals in ore deposits are sulfides. When a sulfide mineral coexists with rock-forming minerals, its solubility is distinctly different from itself alone. The change in dissolution character of a mineral with coexisting rock-forming minerals leads to particular geochemical behavior. The concept of solubility of a metallic mineral with coexisting rock-forming minerals and its theory and model of calculation are put forward. Taking Tianmashan Cu-Au ore deposit of sulfide minerals in Tongling district as an example, solubilities of some metallic minerals with other coexisting minerals, such as pyrite or chalcopyrite with quartz (representing sandstone) or calcite (representing limestone), are calculated. The results show the mechanism of ore-forming processes. As the ore-forming fluid flows through sandstone, it dissolves pyrite in the sandstone at first, then transports the iron and sulfur to the interface between sandstone and limestone and eventually precipitates them on the interface.  相似文献   

Experimental study on supercritical phenomena of WO_3 solubility in NaCl-H_2O system   总被引：3，自引：0，他引：3  

龚庆杰  岑况  於崇文 《中国科学D辑(英文版)》2003,46(7)

The singular behavior of supercritical fluids was found more than one hundred years ago. In 1879, English scientists Hannay and Hogarth[1] firstly studied the properties of supercritical fluids collectively and discovered that ethanol and carbon tetrachlo…  相似文献   

Geochemical Modelling as a Tool for Actinide Speciation during Anoxic Leaching Processes of Nuclear Fuel     

M. Amme 《Aquatic Geochemistry》2002,8(3):177-198

The behaviour of many radiotoxic elements, which are contained within spent nuclear fuel planned for direct disposal, is strongly dependent on the redox chemistry of the aqueous media present in the deep geological systems, where such disposal options are investigated. Especially actinide elements are known to be sensitive. The knowledge of the speciation of actinides in the case of a possible mobilisation by intruding groundwater is therefore crucial and part of the source term calculation of many countries' performance assessment procedures. In this study, the influence of redox conditions and complexant concentration in two selected groundwaters upon the species distribution of U and Pu is assessed by using the thermodynamic modeling code PHREEQC version 2.3. The modeled systems were derived from laboratory leaching experiments testing nuclear fuel dissolution. For the calculations, critically reviewed data for U and Pu complexation were used. The results show that under the conditions calculated, U and Pu are present mainly as U(VI) and Pu(IV). The presence of solid UO₂ substrate is supposed to change this distribution. The calculational use of different groundwaters as aqueous phase, implying a slightly different solution composition, affects U and Pu speciation: U species distribution is affected mainly by complexant concentration, Pu species are influenced by pH changes. A sensitivity study on Pu speciation is performed; constants changed within their confidence intervals were applied. The results are compared with experimental observations, and differences and possible expected effects during the dissolution of real, complex materials are discussed.  相似文献   

Experimental Study of Sulfur Solubility in Silicate Melts Coexisting with Graphite as a Function of Silicate Melt Composition     

Tomoyuki Tsujimura  Arashi Kitakaze 《Resource Geology》2005,55(1):55-60

Abstract. Sulfur (S) solubility is determined in silicate melts, in particular with low-FeO content coexisting with graphite. In a high FeO range (>10 mol %), the S solubility is strongly dependent on the FeO content in silicate melt, which is in good agreement with previous works. In an intermediate FeO range (1∼10 mol %), the S solubility in melts with a multi-component system is higher than that in melts with a simple system. The SKα shift of the electron microprobe shows the dissolve sulfur is all sulfide. A positive dependence is observed between CaO and S content in the melt undoped with FeO, but the dissolved sulfur is sulfate. The relationship between melt composition, S content, and S oxidation state is discussed.  相似文献   

Solubility of gold in the SiO2-NaCl-H2O system at 300°C and50 MPa     

Yishan Zeng  Fengzhen Wang  Ruiying Ai 《中国科学D辑(英文版)》1997,40(5):485-490

The solubility of gold and quartz in 0.01, 0.10 and 1. 00 mol/kg NaCl solutions with various pH was determined in the presence of the NNO oxygen buffer at 300°C and 50 MPa using a flexible gold cell hydrothermal apparatus. The Au speciation in the SiO₂-NaCI-H₂O system was inferred and the equilibrium constants for the following dissolution reactions were obtained: Au+H₂O = AuOH⁰+1/2H₂, logK(AuOH⁰) = -7.92 ± 0.25; Au+Cl^-+H₂O = AuOHCl^-+1/2H₂, logK(AuOHCl^-) = - 7. 56 ± 0.65. The present study suggests that Au as AUOH⁰ and AuOHCl^- is basically transported in ore-forming solutions under geologically realistic conditions of acidity, chloride molality and oxygen fugacity. The reason for the common association of Au with SiO₂ in hydrothermal gold deposits is discussed. Project supported hy the National Natural Science Foundation of China.  相似文献   

Experimental Study on the Solubility of Cr^2 in Olivine,Orthopyroxene and Spinel Solid Solutions     

Li Jianping  Hugh St. C. O’Neill  Friedrich Seifert 《中国地球化学学报》1997,16(2):139-147

Experiments have been performed on the system MgO-SiO2-Cr-O at 0-2.88 GPa and 1100-1450℃,focusing on the stability of Cr^2 in olivine(O1),orthopyroxene(Opx) and spinel(Sp) and its partitioning between these phases.Analytical reagent grade chemicals,MgO,SiO2,Cr2O3.and Cr were used to make starting mixtures.Excess Cr(50%) was then added in these mixtures to ensure that the resultant phases were in equilibrium with the metal Cr.Flux of BaO B2O3(%) was added for facilitating experimental equilibrium and crystal growth.Cr was used as capsule material.All phases in the product were identified by X-ray and analyzed by electron microprobe,The contents of CrO in the different phases(O1,Opx and Sp)were calculated according to stoichiometry.The obtained results of calculation indicate that Cr^3 in Ol and Opx is negligible.The experimental results show;(a) with increasing temperature and decreasing pressure,Cr^2 solubility in Ol,Opx and Sp increases;(b) with in creasing temperature,the partitioning coefficient of Mg and Cr^2 between Ol and Opx decreases,that between Opx and Sp increases,and that between Ol and Sp remains almost unchanged;(c) the effect of pressure on all partitioning coefficients is negligible.  相似文献   

钴,锶在包气带土壤中迁移特征的试验研究     

独仲德 《水文地质工程地质》1997,24(6):9-12

在中国辐射防护研究院试验场Ｃｏ＾２＋（ＣｏＣｌ２．６Ｈ２Ｏ），Ｓｒ＾２＋「Ｓｒ（ＮＯ３）２作喷淋液进行了１４４０ｈ的淋滤试验，得到了Ｃｏ＾２＋，Ｓｒ＾２＋在气带土壤中迁移的平均阻滞系数；  相似文献   

Fractional crystallization of salts from subsoil brines – I     

V.P. Mohandas  S.J. Gohil  S.D Gomkale 《International Journal of Salt Lake Research》1997,6(4):331-351

Solar evaporation studies of subsoil brines from three different locations of Gujarat State in India were undertaken. Evaporation of brines from their initial densities to 29-30°Be’ density was studied and the data were compared with those of sea brine. From the experimental data, the change in the quality of salts crystallized at various density levels with changing ionic composition of brines is explained theoretically and the ionic composition of an ideal brine and proper density ranges for the recovery of high quality salt are identified. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

含水氯化物体系中金和银的相对溶解度测定     

郁云妹  莫德明 《矿物学报》1995,15(2):168-175

文章叙述了用Ａｕ－Ａｇ合金测定Ａｕ和Ａｇ溶解度及讨论Ａｕ的热液行为的意义和方法。实验结果指出：在３００℃，ｆｏ２在１０＾－３５￣１０＾１４间，ΣＣ１＝３．０ｍｏｌ／ｋｇ和有含银矿物存在时，Ａｕ－Ａｇ系列与含水氯化物热液反应，Ａｕ－Ａｇ系列中纯Ａｕ的溶解度最高，中间组分的溶解度随ＸＡｕ的增加而升高，而银的溶解度随ＸＡｇ的变化不明显，但随ΣＣ１＾－浓度的增加而升高，在含银相存在时，金和银总是趋向于形成  相似文献