New Mexico Geological Society Annual Spring Meeting — Abstracts

The solubility of tellurium dioxide in water vapor at 250°C

Jonathan Reed Adams1, Nicole C. Hurtig1, Alexander P. Gysi2 and Artaches Migdissov3

1New Mexico Institute of Mining and Technology, 801 Leroy Pl, Socorro, NM, 87801, United States,
2New Mexico Bureau of Geology and Mineral Resources, 801 Leroy Place, Soc, NM, 87801, USA
3Los Alamos National Laboratory, Los Alamos, NM, 87545, USA

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Tellurium is a critical mineral of increasing importance in green energy technologies. Numerical simulations using previous thermodynamic data predict up to ~0.1 ppm in epithermal vapor with H2Te(g) as the dominant vapor species [1]. However, fluid inclusion studies show up to hundreds of ppm Te in vapor inclusions from epithermal ore deposits [2]. In this study, we measured experimentally the solubility of tellurium in hydrothermal vapors to determine the hydrated tellurium speciation in water vapor. Hydration is the effect of water vapor molecules binding to a metal, greatly increasing its solubility [3]. Experiments were conducted in batch-type Ti Parr reactors at 250°C and a range of water vapor pressures (PH2O) using several different oxygen buffers (e.g., MoO2-MoO3, WO2-WO3 and Ni-NiO). Kinetic experiments were conducted between 1-25 days at 250°C and 20 bar and at different redox conditions. At oxidizing conditions, equilibrium conditions were reached after ~10 days with 1.33 ±0.01 ppm dissolved Te, whereas in N2-degassed experiments equilibrium was reached after ~22 days with 0.669 ±0.004 ppm dissolved Te, indicating slower reaction kinetics and reduced solubility at lower redox conditions. Experiments at 250°C and logfO2 of -24 (MoO2-MoO3 buffer), show increasing Te solubility with increasing PH2O ranging from 1-3 ppm between 15-25 bar to 12.27±0.01 ppm Te at 35 bar. The MoO2-MoO3 buffered experiments overlap in concentrations with results from the kinetic series at oxidizing conditions. Experiments at 250°C and logfO2 of -39.37 (WO2-WO3 buffer), show an increase in Te solubility between 15-35 bar from 14.51 ppm up to 15.45±0.01 ppm. Previous experimental work has shown enhanced solubility of TeO2 in water vapor due to the formation of TeO2*xH2O with x = 1 and 2 [1,4-5], whereas in this study Te shows higher hydration numbers similar to other metals [3]. Our results demonstrate the significant role of PH2O on Tesolubility in low density fluids as wellas a strong redox control based on results from the WO2-WO3 buffered experiment. The experimental data generated can be applied in thermodynamic models to discern tellurium mobility in hydrothermal systems.


  1. [1] Grundler et al., (2013) Geochim. et Cosmochim. Acta120, 298–325.
  2. [2] Wallier et al., (2006) Economic Geology101, 923–954.
  3. [3] Hurtig et al., (2021) Economic Geology 116, 1599-1624.
  4. [4] Glemser et al., (1964) Z. anorg. allg. Chem. 329, 51-55.
  5. [5] Glemser et al., (1966) Omagiu Raluca Ripan, Editura Acedemiei Republici Socialiste Romania,Bucarest, 253-262.
pp. 16

2023 New Mexico Geological Society Annual Spring Meeting
April 21, 2023, Macey Center, Socorro, NM
Online ISSN: 2834-5800