Experimental study of the stability of MoO2CL2° (aq) in hydrothermal solutions at 100-350 °C and saturated vapor pressure

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Abstract

The solubility of crystalline MoO3 in HCl solutions with variable concentration was investigated at 100, 155, 200, 250, 300, 350 °C and saturated vapour pressure. The results showed that MoO3 solubility increases with HCl concentration. Using the OptimA program, Gibbs energies of MoO2Cl2 complex have been determined. The stability constants of MoO2Cl2 are calculated according to the reaction: MoO3(c) + 2HCl(aq) → MoO2Cl2o(aq) + + H2O (l). The pK values are 1.07 0.29; 1.06 0.49; 1.74 0.71; 1.83 0.47; 1.50 0.28; 0.95 0.57 at 100, 155, 200, 250, 300, 350 °C (saturated vapour pressure).

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About the authors

A. A. Yakimenko

Lomonosov Moscow State University

Author for correspondence.
Email: yakimenko_alice@mail.ru

Faculty of Geology

Russian Federation, Leninskie Gory, 1, Moscow, 119991

A. Yu. Bychkov

Lomonosov Moscow State University

Email: bychkov@geol.msu.ru

Faculty of Geology

Russian Federation, Leninskie Gory, 1, Moscow, 119991

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Supplementary files

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2. Fig. 1. Dependence of the solubility of molybdenum (VI) oxide in HCl on the duration of the experiment at 155 °C.

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3. Fig. 2. Dependence of the solubility of molybdenum (VI) oxide on the logarithm of the HCl concentration at a temperature of 155 °C.

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4. Fig. 3. Dependence of the solubility of molybdenum (VI) oxide on the logarithm of the HCl concentration at temperatures from 100 to 350 °C.

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5. Fig. 4. Dependence of K4 on temperature during extrapolation.

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6. Fig. 5. Diagram of the fields of predominance of Mo (VI) forms in HCl solution at T from 100 to 450 °C and P from 1 to 1000 bar.

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