Solubility of Na2SO4 in silica-saturated solutions: Implications for REE mineralization

2020 ◽  
Vol 105 (11) ◽  
pp. 1686-1694 ◽  
Author(s):  
Huan Chen ◽  
Hao Cui ◽  
Richen Zhong ◽  
Yuling Xie ◽  
Chang Yu ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Inductively Coupled Plasma ◽  
Mining Area ◽  
Fused Silica ◽  
Dissolution Behavior ◽  
Solubility Curve ◽  
Mass Balance Calculation ◽  
Inductively Coupled ◽  
Fused Silica Capillary ◽  
Sulfate Melt

Abstract Sulfate is traditionally considered to have retrograde solubility in aqueous solutions. However, our recent hydrothermal diamond-anvil cell (HDAC) experiments have shown that the solubility of Na2SO4 changes from retrograde to prograde in the presence of silica, leading to the formation of sulfate-rich solutions at high temperatures, in line with observations on natural geofluids. In this study, we use synthetic inclusions of fused silica capillary capsules containing saturated Na2SO4 solutions and Na2SO4 crystals to quantitatively investigate the solubility of Na2SO4 at different temperatures in the Na2SO4-SiO2-H2O system. Sulfate concentrations were measured using Raman spectroscopy and calibrated using Cs2SO4 solutions with known concentrations. The solubility of crystalline Na2SO4 dropped slightly when heated from 50 to 225 °C and dramatically from 225 to 313 °C. At 313 °C, the Na2SO4 crystals began to melt, forming immiscible sulfate melt coexisting with the aqueous solution, with or without solid Na2SO4. With the formation of sulfate melt, the solubility of Na2SO4 was reversed to prograde (i.e., solubility increased considerably with increasing temperatures). The solubility of Na2SO4 in the measured solution was significantly higher than that predicted in the absence of SiO2 over the entire temperature range (except for temperatures around 313 °C). This indicates that the presence of SiO2 greatly changes the dissolution behavior of Na2SO4, which may be caused by the formation of a sulfate–silicate intermediates such as Si(OH)4SO42−. Considering that most crustal fluids are silica-saturated, the solubility curve of Na2SO4 obtained in this study can better reflect the characteristics of geofluids when compared to that of Na2SO4-H2O binary system. At temperatures of 313–425 °C, the solubility of Na2SO4 increases with temperature following the function Csulfate = –3173.7/T + 5.9301, where Csulfate and T represent the solubility of Na2SO4 in mol/kg H2O and temperature in Kelvin, respectively. As an application, this temperature-solubility relationship can be used to evaluate the sulfate contents in fluid inclusions that contain sulfate daughter minerals, based on the temperature of sulfate disappearance obtained from microthermometric analysis. The sulfate concentrations of the ore-forming fluids of the giant Maoniuping carbonatite-related rare earth element (REE) deposit (southwest China) were calculated to be 4.67–4.81 m (mol/kg H2O). These sulfate concentrations were then used as internal standards to calibrate the previously reported semi-quantitative results of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis of REE-forming stage fluid inclusions at this deposit. The calculated Ce concentrations in the REE-mineralizing fluid range from 0.42 to 0.49 wt%. The high fluid REE contents suggest that the sulfate-rich fluids are ideal solvents for REE transport. A mass-balance calculation was carried out to evaluate the minimal volume of carbonatite melt that was required for the formation of the giant Maoniuping REE deposit. The result indicates that the carbonatite dikes in the mining area are enough to provide the required fluids and metals, and thus a deep-seated magma chamber is not necessary for ore formation.

Ultrasonic-Assisted Dialysis Coupled with CE-ICP-OES for Determination of Calcium Species in the Dialysate of Human Blood

2011 ◽  
Vol 343-344 ◽  
pp. 769-773
Author(s):  
Bi Yang Deng ◽  
Xiang Shu Xu ◽  
Ying Zi Wang ◽  
Ping Chuan Zhu
Keyword(s):  
Human Blood ◽  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Fused Silica ◽  
Emission Spectrometry ◽  
Icp Oes ◽  
Buffer Solution ◽  
Inductively Coupled ◽  
Ultrasonic Assisted ◽  
Fused Silica Capillary

The analytical method for calcium species in human blood was studied using ultrasonic-assisted dialysis coupled with capillary electrophoreisi (CE) inductively coupled plasma optical emission spectrometry (ICP-OES). The optimal ultrasonic dialysis conditions were 72 W power, 60 min extraction time and 70 μL volume of blood sample. Ultrasonic-assisted dialysis improves significantly the dialysis efficiecy by comparing with balance dialysis. The optimized conditions of separation and detection (a 120 cm length×100 μm i.d. fused-silica capillary, 20 kV separation voltage, 30 mmol/L Tris-HCl with pH7.4 buffer solution) for calcium species were achieved by CE-ICP-OES. The forms of calcium in the dialysate of human blood have five different species. The concentration of free Ca2+ in the dialysate was 0.7 mg/L. The hyphenated technique is simple and convenience, which is fit for the separation and analysis of metal-containing biological samples.

Mechanistic Studies of Chromium Speciation with Thermospray

2002 ◽  
Vol 56 (9) ◽  
pp. 1152-1160 ◽  
Author(s):  
Xiaohua Zhang ◽  
John A. Koropchak
Keyword(s):  
Inductively Coupled Plasma ◽  
Atomic Emission ◽  
Deposition Process ◽  
Fused Silica ◽  
Chromium Speciation ◽  
Aerosol Formation ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Fused Silica Capillary ◽  
Plasma Mass Spectrometry

Thermospray (TSP) coupled with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) or inductively coupled plasma-mass spectrometry (ICP-MS) has been developed as a non-chromatographic method for chromium speciation to quantitatively separate and determine two chromium oxidation states: Cr(III) and Cr(VI). The limits of detection can reach 0.5 ng/mL with ICP-AES detection and 50 pg/mL with ICP-MS detection. The basis for this speciation method is that Cr(III) can selectively and nearly quantitatively deposit inside a thermospray system as Cr2O3, while Cr(VI) does not. To fully understand the mechanism of this deposition process, four questions were investigated: is aerosol formation necessary for the reaction to occur? Does the deposition occur in the aerosol or liquid regime? Does the deposit tend to be retained on the surface of the fused silica capillary? Can the reaction be predicted from thermodynamic calculations? These studies show that this reaction happens before solvent evaporates (i.e., the liquid regime). The high temperature inside the thermospray system is the major factor triggering this reaction. At the same time, the high pressure is important for its influence on the solvent boiling point, which affects the residence time (the time that the analyte spends in the solution before the solvent evaporates) and the kinetics of the reaction. The effects of the other parameters (vaporizer length, heating length, drawn tip, etc.) on the efficiency of the deposition reaction, represented as background residual signal (BRS), were also studied.

scholarly journals LA-ICP-MS analysis of fluid inclusions: contamination effects challenging micro-analysis of elements close to their detection limit

2017 ◽  
Vol 32 (5) ◽  
pp. 1052-1063 ◽  
Author(s):  
Katerina Schlöglova ◽  
Markus Wälle ◽  
Christoph A. Heinrich
Keyword(s):  
Mass Spectrometry ◽  
Fluid Inclusions ◽  
Inductively Coupled Plasma ◽  
Analytical Procedure ◽  
Inductively Coupled ◽  
Natural Minerals ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Reliable Quantification ◽  
Micro Analysis

This paper presents a practical guide to an optimized analytical procedure for the reliable quantification of trace element concentrations in fluid inclusions hosted by natural minerals, using laser ablation inductively coupled plasma mass spectrometry (ICP-MS).

Fluid compositions reveal fluid nature, metal deposition mechanisms, and mineralization potential: An example at the Haobugao Zn-Pb skarn, China

Geology ◽  
2020 ◽  
Author(s):  
Qihai Shu ◽  
Zhaoshan Chang ◽  
John Mavrogenes
Keyword(s):  
Inductively Coupled Plasma ◽  
Isotope Composition ◽  
Northeastern China ◽  
Metal Deposition ◽  
Mass Balance Calculation ◽  
Inductively Coupled ◽  
Mineralization Potential ◽  
Plasma Mass Spectrometry ◽  
Absolute Concentrations ◽  
Potential Tool

Fluid inclusion compositions obtained from laser ablation–inductively coupled plasma–mass spectrometry at the Haobugao Zn-Pb skarn in northeastern China provide constraints on fluid origin, evolution, and metal deposition mechanisms and an example of evaluating mineralization potential. Metal concentrations in the prograde fluids were high (up to 1.4 wt% Zn and 1.8 wt% Pb) but remained in solution, likely due to the high temperatures (440–575 °C) and salinities (35.4–45.3 wt% NaCl equivalent). Absolute concentrations of elements (e.g., Rb and Na) and mass ratios (e.g., Zn/Na and K/Na) reveal that the early, prograde fluids were magmatic, consistent with the oxygen isotope composition of fluids (δ18OH2O = 5.5‰–8.5‰). Later mixing with a meteoric fluid caused dilution and Zn-Pb deposition, as revealed by lowered element concentrations and Pb/(Na + K) and Zn/(Na + K) ratios in the sulfide-stage fluid inclusions. Elevated Ca/K ratios in sphalerite-hosted inclusions indicate fluid-carbonate reactions that buffered fluid pH, also facilitating Zn-Pb precipitation. Although cassiterite and molybdenite occur locally at Haobugao, mass balance calculation shows low metal endowment (maximum 2900 t Sn and 2200 t Mo) of the system. Furthermore, the generally unchanged Sn/(Na + K) and Mo/(Na + K) ratios from pre- to late-mineralization fluids suggest that the fluids were never saturated in Sn and Mo. Therefore, finding much Sn or Mo at Haobugao is unlikely. This demonstrates a potential tool for evaluating the metal endowment of a mineral prospect, which may guide exploration.

scholarly journals Mineralogical characteristics and sources of alkali metals in the No. 6 coal seam from the Fukang mining area of the Zhunnan coalfield, Xinjiang province, Northwest China

2019 ◽  
Vol 37 (3) ◽  
pp. 1162-1181 ◽  
Author(s):  
Yun Xu ◽  
Handong Liang ◽  
Ning Zhang
Keyword(s):  
Coal Seam ◽  
Inductively Coupled Plasma ◽  
Alkali Metals ◽  
Northwest China ◽  
Mining Area ◽  
Major Elements ◽  
Middle Part ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry

Minerals in coal are of great significance in determining coal properties, washing, combustion, gasification, and liquefaction. The content of alkali metals in coal is an important factor determining corrosion and/or erosion in combustion boilers. Eleven coal samples were taken from the No. 6 coal seam of the Fukang mining area, Zhunnan coalfield, Xinjiang province, China. X-ray fluorescence, inductively coupled plasma-mass spectrometry, low-temperature ashing-X-ray diffraction, and electron probe microanalyzer were used for analyzing the minerals, major elements, and trace elements of the coal. The results indicated that the minerals mainly consist of dawsonite, dolomite, albite, calcite, kaolinite, quartz. The average content of Na2O in the ash of the No. 6 coal seam samples was 10.91%. Na mainly occurs in the form of organic compounds in the No. 6 coal seam, then in the form of inorganic minerals, such as dawsonite and albite. Na in surface and underlying strata was brought into the coal by water and combined with organic matter, resulting in relatively high Na contents in the upper and bottom parts of the coal seam and relatively low Na contents in the middle part.

High Throughput Speciation Analysis of Mercury in Water Environment by Short Column Capillary Electrophoresis On-Line Coupled with Inductively Coupled Plasma Mass Spectrometry

2011 ◽  
Vol 383-390 ◽  
pp. 790-795
Author(s):  
Bao Hui Li ◽  
Bao Juan Tian
Keyword(s):  
Mass Spectrometry ◽  
Capillary Electrophoresis ◽  
High Throughput ◽  
Inductively Coupled Plasma ◽  
Speciation Analysis ◽  
Fused Silica ◽  
Short Column ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

A method for mercury high throughput rapid speciation analysis was built by short column capillary electrophoresis (SC-CE) coupled with inductively coupled plasma mass spectrometry (ICP-MS). A micromist nebulizer was employed to increase the nebulization efficiency and a laboratory-made removable SC-CE-ICP-MS interface on the basis of cross design was applied to alleviate buffer contamination of ICP-MS. In less than 60 s methylmercury (MeHg(I)) and inorganic mercury (Hg(II)) were separated in a 16 × 75 μm i.d. short column fused-silica capillary at 21 kV, while a mixture of 30 mmol/L boric aicd + 5% (v/v) CH3OH (pH=8.60) acted as running electrolyte. The precisions (RSD, n=5) of migration time and peak area for MeHg(I) and Hg(II) were in the range of 1.4-2.6% and 3.3-3.4%, respectively. The limits of detection (3σ) mercury species were 9.7 and 12.0 μg/L, respectively. The recoveries for Hg(II) MeHg(I) were in the range of 96-107% and 99-105%.

scholarly journals Aquamarine from Thach Khoan Mining Area in Phu Tho Province, Vietnam

2017 ◽  
Vol 33 (2) ◽  
Author(s):  
Dương Lý Thùy
Keyword(s):  
Inductively Coupled Plasma ◽  
Mining Area ◽  
Global Market ◽  
Type I ◽  
Electron Probe Micro Analysis ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Micro Analysis ◽  
Raman And Ir Spectroscopy

Abstract: Aquamarine is a kind of gemstone having attractive color, valuable and being a potential material in gemological industry. In Vietnam, Thach Khoan area has become a noticeable location to explore aquamarine. However, the researches of aquamarine are still limited. Therefore, this study was conducted to determine the characteristics of aquamarine. Eight aquamarine samples from granitic pegmatites in Thach Khoan commune, Thanh Son District, Phu Tho Province were investigated by classical gemological methods, Electron Probe Micro-analysis (EMPA) and Laser Ablation – Inductively Coupled Plasma – Mass Spectrometry (LA-ICP-MS) methods, Raman and Fourier transform infrared (FTIR) spectroscopy. Results showed that aquamarine presents a low concentration of alkali and high amount of iron. Raman and IR spectroscopy indicate the vibrations of specific bonds including Si-O, Al-O, Be-O, the presence of CO2 and type I H2O in structural channels. By dint of that, we are going to study the potential treatment methods of aquamarine in Vietnam in the following study to enhance its quality as well as value in the global market.

Tin and associated metal and metalloid geochemistry by femtosecond LA-ICP-QMS microanalysis of pegmatite–leucogranite melt and fluid inclusions: new evidence for melt–melt–fluid immiscibility

2012 ◽  
Vol 76 (1) ◽  
pp. 91-113 ◽  
Author(s):  
A. Y. Borisova ◽  
R. Thomas ◽  
S. Salvi ◽  
F. Candaudap ◽  
A. Lanzanova ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Inductively Coupled Plasma ◽  
Melt Inclusions ◽  
Saturation Index ◽  
Femtosecond Laser Ablation ◽  
Type A ◽  
Inductively Coupled ◽  
Melt And Fluid Inclusions ◽  
Layer Effect ◽  
Primary Melt

AbstractGranitic pegmatites are exceptional igneous rocks and the possible role of an immiscibility process in their origin is strongly debated. To investigate metal and metalloid behaviour in hydrous peraluminous systems (aluminium saturation index, ASI >1), we analysed 15 quartz-hosted primary melt and fluid inclusions from pegmatites in the Ehrenfriedersdorf Complex (Erzgebirge, Germany) and 26 primary melt inclusions from leucogranites of the Ehrenfriedersdorf district (Germany), Kymi (Finland) and Erongo (Namibia) by femtosecond laser ablation inductively coupled plasma quadrupole mass spectrometry. The results presented here for 32 elements provide evidence for metal and metalloid fractionation between two types of immiscible melts (A and B) and NaCl – HCl-rich brine in the pegmatite system. No evidence for the boundary layer effect was observed in the 40 – 500 μm size melt inclusions that were investigated. The data on the Ehrenfriedersdorf pegmatites allow quantification of the metal and metalloid partitioning between natural NaCl-rich brine and the two types of melt (e.g. KAsbrine/type-A,B melts = 0.01 – 1.7; KSbbrine/type-A,B melts = 10 – 285; KZnbrine/type-A,B melts ≥ 50; KPbbrine/type-A melt ≥ 50; KAgbrine/type-A melt = 46). These data are in accord with existing natural and experimental data on equilibrium fluid – melt partitioning as well as spectroscopic data on the metal and metalloid complexation in hydrous aluminosilicate melts and NaCl – HCl-rich fluids.

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