Abstract
The activity of HC1 in solutions of HCl-NaCl, and the approximate values of the activities of H+ and Cl− in solutions of HC1, HC1O4, HCl-NaCl, HClO4-NaClO4 and HC1O4-NaCl were determined at 25 ° by measuring the electromotive force of a cell consisting of a Pt-Pt black electrode and an Ag-AgCl electrode. The liquid junction potential, estimated by using Henderson’s equation as a first approximation, was subtracted from the measured electromotive force of the cell. Some hydrometallurgical problems which were difficult to understand with the concept of concentration were re-examined, using the activity values thus determined. These problems were the rate of non-oxidative leaching of galena and sphalerite, the acid dissolution rate of cupric oxide, and the rate of oxidation of Fe(II) with molecular dissolved oxygen. Although the dependence of the dissolution rates of galena, sphalerite and cupric oxide upon acid concentration appeared to be rather complicated, the dissolution rates of these minerals were found to be of first order with respect to aH+. It was also possible to elucidate the role of Cl− ions by using thea Cl-values. A rate equation obtained experimentally for the autoxidation of Fe(II) in HC1 solutions was found to generally explain the experimental results of previous researchers, which seemed to be inconsistent with each other.
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I. H. Warren and E. Devuyst:Intern. Symp. on Hydrometallurgy, Chicago, AIME, D. I. J. Evans and R. S. Shoemaker, eds., 1973, p. 229.
L. D. Locker and P. L. deBruyn:J. Electrochem. Soc, 1969, vol. 116, p. 1659.
H. S. Harned and B. B. Owen:The Physical Chemistry of Electrolytic Solutions, 3rd ed. Reinhold Publishing Co., New York, 1963.
K. S. Pitzer:J. Am. Chem. Soc, 1937, vol. 59, p. 2365.
H. P. Meissner and J. W. Tester:Ind. Eng. Chem. Process Des. Develop., 1972, vol. 11, p. 128.
D. Dobos:Electrochemical Data, Elsevier Scientific Publishing Co., Amsterdam, 1975.
K. S. Pitzer and L. Brewer:Thermodynamics 2nd ed., Revision of Lewis and Randall, McGraw-Hill, New York, 1961, p. 310.
H. S. Harned and T. R. J. Paxton:Phys. Chem., 1953, vol. 57, p. 531.
K. J. Vetter:Electrochemical Kinetics, Academic Press, New York, 1967, p. 46.
D. J. G. Ives and G. J. Janz:Reference Electrodes, Academic Press, New York, 1961.
H. S. Harned and R. W. Ehlers:J. Am. Chem. Soc, 1933, vol. 55, p. 2173.
G. Akerlöf and J. W. Teare:J. Am. Chem. Soc, 1937, vol. 59, p. 1855.
W. J. Moore:Physical Chemistry 3rd. ed., Prentice-Hall, N.J., 1962.
R. A. Robinson and R. H. Stodes:Electrolyte Solutions 2nd ed., Academic Press, New York, 1965.
M. Takahasi:Boshoku Gijutu, 1974, vol. 23, p. 625.
K. Schwabe:Electrochim. Acta., 1967, vol. 12, p. 67.
K. Schwabe et al.:her. Busenges. Phys. Chem., 1067, vol. 71, p. 101;Electrochim. Acta., 1968, vol. 13, p. 1837.
Y. Awakura, S. Kamei and H. Majima:Met. Trans. B, 1980, vol. 11B, p. 377.
N. Misaki: Thesis for Master of Eng., Kyoto University, 1979.
H. Majima, Y. Awakura, T. Yazaki and Y. Chikamori:Met. Trans. B, 1980, vol. 11B, p. 209.
A. M. Posner:Trans. Faraday Soc, 1953, vol. 49, p. 382.
T. Yano, T. Suetaka, T. Umehara, K. Konishi and A. Horiuchi:Nippon Kagaku Kaishi, 1974, vol. 8, p. 1375.
M. Iwai, H. Majima and T. Izaki:Denki Kagaku, 1979, vol. 47, p. 409.
M. Iwai and H. Majima:Denki Kagaku, 1979, vol. 47, p. 717. $
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On leave-of-absence to the Department of Metallurgy and Material Science, University of Toronto, Ontario, Canada.
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Majima, H., Awakura, Y. Measurement of the activity of electrolytes and the application of activity to hydrometallurgical studies. Metall Trans B 12, 141–147 (1981). https://doi.org/10.1007/BF02674767
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DOI: https://doi.org/10.1007/BF02674767