Effects of pH and Salinity on the Hydrothermal Transport of Tungsten: Insights from In Situ Raman Spectroscopic Characterization of K2WO4-NaCl-HCl-CO2 Solutions at Temperatures up to 400°C
Joint Authors
Wang, Xiaolin
Chou, I-Ming
Qiu, Ye
Zhang, Rongqing
Li, Guanglai
Zhong, Richen
Source
Issue
Vol. 2020, Issue 2020 (31 Dec. 2020), pp.1-12, 12 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2020-02-12
Country of Publication
Egypt
No. of Pages
12
Main Subjects
Abstract EN
In situ Raman spectra of aqueous K2WO4-HCl, K2WO4-HCl-NaCl, and K2WO4-CO2-NaCl solutions were collected at elevated temperature (T, 100–400°C) and constant pressure (P) of 30 MPa.
The stretching vibration band of the W=O bond (v1) was analyzed to reveal the species of tungsten (W) responsible for the hydrothermal transport of W during mineralization.
Results showed that monomeric tungstates with v1(W=O) bands at ~930 and 950 cm-1 are the dominant W species in weakly alkaline (room temperature, pH=7.7) to near-neutral (room temperature, pH=7.2) solutions under the investigated T‐P conditions.
Overall, the stability of polymeric tungstate species with v1(W=O) bands at ~965–995 cm-1 decreases with rising temperature and was not detected at ≥300°C in moderately acidic solution (room temperature, pH=4.9).
However, increased fluid acidity and salinity obviously enlarged the temperature stability field of polymeric tungstate species.
In highly acidic solution (room temperature, pH=1.4), polymeric tungstates are the only stable W species even at 400°C.
In the presence of 1.9 mol/kg NaCl, polymeric tungstate(s) can persist to at least 350°C in moderately acidic solution.
Considering that 300–350°C is the major W-mineralizing T range and W-mineralizing fluid is generally characterized by a moderately acidic nature, we propose that, in addition to monomeric tungstates, polymeric tungstates can also be important W species in some natural geological fluids that are responsible for the mineralization of W.
Future studies of the W mineralization mechanism should take this issue into account.
American Psychological Association (APA)
Wang, Xiaolin& Qiu, Ye& Chou, I-Ming& Zhang, Rongqing& Li, Guanglai& Zhong, Richen. 2020. Effects of pH and Salinity on the Hydrothermal Transport of Tungsten: Insights from In Situ Raman Spectroscopic Characterization of K2WO4-NaCl-HCl-CO2 Solutions at Temperatures up to 400°C. Geofluids،Vol. 2020, no. 2020, pp.1-12.
https://search.emarefa.net/detail/BIM-1159486
Modern Language Association (MLA)
Wang, Xiaolin…[et al.]. Effects of pH and Salinity on the Hydrothermal Transport of Tungsten: Insights from In Situ Raman Spectroscopic Characterization of K2WO4-NaCl-HCl-CO2 Solutions at Temperatures up to 400°C. Geofluids No. 2020 (2020), pp.1-12.
https://search.emarefa.net/detail/BIM-1159486
American Medical Association (AMA)
Wang, Xiaolin& Qiu, Ye& Chou, I-Ming& Zhang, Rongqing& Li, Guanglai& Zhong, Richen. Effects of pH and Salinity on the Hydrothermal Transport of Tungsten: Insights from In Situ Raman Spectroscopic Characterization of K2WO4-NaCl-HCl-CO2 Solutions at Temperatures up to 400°C. Geofluids. 2020. Vol. 2020, no. 2020, pp.1-12.
https://search.emarefa.net/detail/BIM-1159486
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1159486