Kinetics of Molybdenum Trioxide Dissolution in the Alkaline Medium

Abstract

The paper presents experimental study results of the MoO₃ powder samples dissolution kinetics in the aqueous ammonia solution at various pH concentrations and values. Molybdenum ions concentration in the filtrate samples was determined spectrophotometrically. Kinetic characteristics were obtained, and kinetic parameters (specific dissolution rate, reaction order with respect to the H⁺ ion) were calculated. It was established that the dissolution rate was increasing in the ammonia solution concentration range of 0.02--1.26 mol/l, and with the growing pH it passed through the maximum. Taking into account the acid-base equilibria constants, the dissolution process was simulated, and its stage-by-stage nature was established. Fractional reaction order with respect to the H⁺ ions calculated from the curves plotted in the α--t/t_0.5 coordinates (affine transformation method) indicated the adsorption mechanism of dissolution. It was shown that the MoO₃ dissolution proceeded with formation of the intermediate adsorption complexes. Due to the HMoO₄^- low concentration in the MoO₃ concentration within the studied pH range by the surface-active particle, on which groups of ions were adsorbed, the MoO₄^- could be considered. The results obtained are an addition to the data possessed on the molybdenum oxide phase and other transitional metals behavior. They could be applied in the practical applications associated with dissolving molybdenum in the alkaline electrolytes

Please cite this article in English as:

Eliseeva E.A., Berezina S.L., Gorichev I.G. Kinetics of molybdenum trioxide dissolution in the alkaline medium. Herald of the Bauman Moscow State Technical University, Series Natural Sciences, 2023, no. 2 (107), pp. 98--109 (in Russ.). DOI: https://doi.org/10.18698/1812-3368-2023-2-98-109

References

[1] Khanturgaeva G.I. Combined technologies for complex processing of refractory molybdenum and tungsten ores. GIAB [Mining Information and Analytical Bulletin], 2009, no. S14, pp. 478--494 (in Russ.).

[2] Marczenko Z. Spectrofotometryczne metody w analizie nieorganicznej. Warszawa, Naukowe PWN, 1998.

[3] Kipriyanov N.A., Gorichev I.G. Modeling of leaching in hydrometallurgy oxidable minerals using theirs acid-basic properties. Vestnik RUDN. Ser. Inzhenernye issledovaniya [RUDN Journal of Engineering Research], 2008, no. 3, pp. 73--78 (in Russ.).

[4] Blesa M.A., Weisz A.D., Morando P.J., et al. The interaction of metal oxide surfaces with complexing agents dissolved in water. Coord. Chem. Rev., 2000, vol. 196, iss. 1, pp. 31--63. DOI: https://doi.org/10.1016/S0010-8545(99)00005-3

[5] Bezdenezhnykh A.A. Inzhenernye metody sostavleniya uravneniy skorostey reaktsiy i rascheta kineticheskikh constant [Engineering methods for compiling reaction rate equations and calculating kinetic constants]. Leningrad, Khimiya Publ., 1973.

[6] Rahnemaie R. Ion adsorption modeling as a tool to characterize metal (hydro)oxide behavior in soil. PhD thesis. Wageningen Univ., 2005.

[7] Blesa M.A. Chemical dissolution of metal oxides. CRC Press, 2018.

[8] Marin G.B., Yablonsky G.S., Constales D. Kinetics of chemical reactions. Wiley, 2011.

[9] Yablonsky G.S., Constales D., Shekhtman S.O., et al. The Y-procedure: how to extract the chemical transformation rate from reaction-diffusion data with no assumption on the kinetic model. Chem. Eng. Sci., 2007, vol. 62, iss. 23, pp. 6754--6767. DOI: https://doi.org/10.1016/j.ces.2007.04.050

[10] Eliseeva E.A., Berezina S.L., Boldyrev V.S., et al. Influence of the morphology of Co₂O₃ particles on the kinetics of dissolution in electrolytes. Tsvetnye metally, 2020, no. 11, pp. 14--18 (in Russ.).

[11] Eliseeva E.A., Berezina S.L., Boldyrev V.S., et al. Modeling the process of dissolving iron oxide Fe₃O₄ in an acidic environment. Chernye metally, 2020, no. 10, pp. 15--20 (in Russ.).

[12] Ferraris G.B., Donating G. A powerful method for Hougen --- Watson model parameter estimation with integral conversion data. Chem. Eng. Sci., 1974, vol. 29, iss. 6, pp. 1504--1509. DOI: https://doi.org/10.1016/0009-2509(74)80177-6

[13] Latimer W.M. In the oxidation states of the elements and their potentials in aqueous solutions. Prentice-Hall, 1938.

[14] Stepanov N.F., Erlykina M.E., Filippov G.G. Metody lineynoy algebry v fizicheskoy khimii [Methods of linear algebra in physical chemistry]. Moscow, MSU Publ., 1976.

[15] Schmid R., Sapunov V.N. Non-formal kinetics. In search for chemical reaction pathways. Weinheim, Chemie, 1982.

[16] Brown M.E., Dollimore D., Galwey A.K. Reactions in the solid state.‎ Elsevier, 1980.

[17] Joung D. Decomposition of solids. Pergamon Press, 1966.

[18] Barret P. Cinetique heterogene. Paris, Gauthier-Villars, 1973.

[19] Rozovskiy A.Ya. Geterogennye khimicheskie reaktsii [Heterogeneous chemical reactions]. Moscow, Nauka Publ., 1980.

[20] Gorichev I.G., Ashkharua F.G., Vaynman S.K. On the applicability of the topochemical model of dissolution of some oxides in acids. Zhurn. fiz. khimii, 1976, vol. 50, no. 6, pp. 1610--1612 (in Russ.).

[21] Petrochenkov V.A., Gorichev I.G., Batrakov V.V., et al. Catalytic effect of ammonia on the kinetics and mechanism of MoO3 dissolution in alkaline solutions. Theor. Found. Chem. Eng., 2004, vol. 38, no. 4, pp. 386--393. DOI: https://doi.org/10.1023/B:TFCE.0000036965.59052.20