I. V. Artamonova, I. G. Gorichev, E. B. Godunov
Moscow State Engineering University (MAMI), Moscow, Russia.
DOI: 10.4236/eng.2013.59085   PDF    HTML     5,645 Downloads   8,803 Views   Citations

Abstract

The kinetics of the interaction of MnO₂, Mn₂O₃, and Mn₃O₄, with sulphuric acid solutions and the effect of oxalic acid on this process are studied. As the sulphuric acid concentration is increased from 0.1 to 5 N, the dissolution rate of Mn₂O₃, Mn₃O₄ to MnO₂ and Mn²⁺ ions decreases, whereas it increases with the concentration of Mn²⁺ ions. Upon the addition of H₂O_x, the complete dissolution of Mn₃O₄ occurs more quickly. The reaction order with respect to the H⁺ and O _x^2- ions is +0.5 ± 0.1. A mechanism of MnO₂ dissolution promotion by O _x^2- is proposed. The dissolution rate was found to depend on the concentrations of MnHO_x ^- ions and was highest at pH 1.6 ± 0.2. A rate law and mechanism are suggested for manganese oxides dissolution.

Keywords

Dual Electrical Layer; Acid-Base Model; The Kinetics of Manganese Oxide Dissolution; Oxalic Acid

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Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	M. A. Blesa, I. M. Perdo and A. E. Regazzoni, “Chemical Dissolution of Metal Oxides,” CRC Press, Boca Ration, 1994.
[2]	S. O. Lee, T. Tran, Y. Y. Park, S. J. Kim and M. J. Kim, “Study on the Kinetics of Iron Leaching by Oxalic Acid,” International Journal of Mineral Processing, Vol. 80, No. 2-4, 2006, pp. 144-152.
[3]	S. K. Mindal and P. C. Banerjee, “Iron Leaching with Oxalic Acid: Effects of Different Physico-Chemical Pa rameters,” International Journal of Mineral Processing, Vol. 74, No. 1-4, 2004, pp. 263-270.
[4]	С. I. Nwoye, “Model for Computational Analysis of Dis solved Haematite and Heat Absorbed by Oxalic Acid So lution during Leaching of Iron Oxide Ore,” Journal of Engineering and Applied Science, Vol. 4, 2008, pp. 22-25.
[5]	D. Panias, M. Taxiarchou, I. Paspaliaris and A. Konto poulos, “Mechanisms of Dissolution of Iron Oxides in Aqueous Oxalic Acid Solutions,” Hydrometallurgy, Vol. 42, No. 2, 1996, pp. 257-265. doi:10.1016/0304-386X(95)00104-O
[6]	D. Panias, M. Taxiarchou, I. Paspaliaris and A. Konto poulos, “Termodynamic Analysis of the Reactions of Iron Oxides: Dissolution in Oxalic Acid,” Canadian Metallur gical Quarterly, Vol. 35, No. 4, 1996, pp. 363-373. doi:10.1016/S0008-4433(96)00018-3
[7]	Y. Wang and A. T. Stone, “Reaction of Mn(III,IV)(hydr) Oxades with Oxalic Acid, Glioxylic Acid, Phosphono formic Acid, Compounds,” Geochimica et Cosmochimica Acta, Vol. 70, 2006, pp. 4477-4490. doi:10.1016/j.gca.2006.06.1548
[8]	Y. Wang Y. and A. T. Stone, “The Citric Acid-Mn(III,IV) O2(s,birnessite) Reaction. Electron Transfer, Complex Formation,” Geochimica et Cosmochimica Acta, Vol. 70, 2006, pp. 4463-4476. doi:10.1016/j.gca.2006.06.1551
[9]	A. T. Stone, “Reductive Dissolution of Manganese(III)/ (IV) Oxide by Subsituted Phenols,” Environmental Sci ence & Technology, Vol. 21, No. 4, 1987, pp. 979-988. doi:10.1021/es50001a011
[10]	A. T. Stone, “Reduction and Dissolution of Manganese (III) and Manganese(IV) Oxides by Organics,” Environmental Science & Technology, Vol. 18, No. 2, 1984, pp. 450-456. doi:10.1021/es00124a011
[11]	A. T. Stone and I. I. Morgan, “Reductive Dissolution of Metal Oxides, in Aquatic Surface Chemistry,” Wiley, New York, 1987.
[12]	A. T. Stone and H. J. Urion, “Kinetics and Reaction Sto ichiometry in the Reductive Dissolution of Manganese(IV) Dioxide and Co(III) Oxide by Hydrocarbons,” Journal of Colloid and Interface Science, Vol. 132, No. 2, 1989, pp. 509-522. doi:10.1016/0021-9797(89)90265-8
[13]	A. K. Lavrukhina and L. V. Yutkina, “Analiticheskaya Khimiya Margantsa (Analytical Chemistry of Manga nese),” Nauka, Moscow, 1974.
[14]	K. Vetter and N. Jaeger, “The Mechanism of Occurrence of Potential of an Electrode from Manganese Dioxide,” In: A. I. Frumkin, Ed., The Basic Questions of Modern Theoretical Electrochemistry, Mir, Moscow, 1965, pp. 253-262.
[15]	B. Delmon, “Introduction a la Cinetique Heterogene, Paris: Technip,” Mir, Moscow, 1972.
[16]	W. F. Tan, S. J. Lu, F. Liu, X. H. Feng, J. Z. He and L. K. Koopal, “Determination of the Point-Of-Zero Charge of Manganese Oxides with Different Methods Including an Improved Salt Titration Method,” Soil Science, Vol. 173, No. 4, 2008, pp. 277-286. doi:10.1097/SS.0b013e31816d1f12
[17]	V. V. Batrakov, I. G. Gorichev and N. A. Kipriyanov, “Influence of a Double Electric Layer on the Kinetics Dissolution Oxides Metals,” Elektrokhim, Vol. 30, No. 4, 1994, pp. 444-458.
[18]	R. Schmidt and V. N. Sapunov, “Neformalnaya kinetika,” Mir, Moscow, 1985.
[19]	A. A. Bezdenezhnykh, “Inzhenernye Metody Sostavle niya Uravnenii Skorostei Reaktsii i Rascheta Kinetiche skikh Konstant (Engeneering Techniques of Formulation of Equations for Reaction Rates and Calculation of Kinetic Constants),” Khimiya, Leningrad, 1974.