Abstract
Conditions for the formation of a nonequilibrium nonstoichiometric metal-deficient layer (NL) on natural pyrrhotites are studied, together with the NL electroreduction and the role NL plays in a nonoxidizing dissolution of pyrrhotite in solutions of sulfuric and hydrochloric acids. To estimate the NL weight, the charge connected with a cathodic peak at about –0.2 V (Ag/AgCl) is used. The peak reflects the irreversible reduction of NL with the formation of hydrogen sulfide, which is confirmed by SEM and XES data. Bulky NL forms in 0.5 M H2SO4at –0.1 to 0.0 V, where the nonoxidizing dissolution rate sharply alters, and at 0.5–1.1 V, where the pyrrhotite oxidation rate is high. The NL growth is controlled by solid-state diffusion, whereas nonoxidizing dissolution of iron is limited by diffusion at 20–30°C and a kinetic stage of dissolution of sulfur at higher temperatures.
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REFERENCES
Vaughan, D.J. and Craig, J.R., Mineral Chemistry of Metal Sulfides, Cambridge: Cambridge Univ. Press, 1978.
Nicol, M.J. and Scott, P.D., J. S. Afr. Inst. Min. Metall., 1979, vol. 79, p. 298.
Hamilton, I.C. and Woods, R., J. Electroanal. Chem., 1981, vol. 118, p. 327.
Hodgson, M. and Agar, G.E., Proc. 2nd Int. Symp. on Electrochemistry in Mineral and Metal Processing, Richardson, P.E., Srinivasan, S., and Woods, R., Eds., Pennington: The Electrochemical Society, 1984, p. 185.
Radyushkina, K.A., Vigdergauz, V.E., Tarasevich, M.R., and Chanturiya, V.A., Elektrokhimiya, 1986, vol. 22, p. 1394.
Chanturiya, V.A. and Vigdergauz, V.E., Elektrokhimiya sul'fidov: Teoriya i praktika flotatsii (The Electrochemistry of Sulfides: A Theory and Practical Applications of Flotation), Moscow: Nauka, 1993.
Makarov, D.V., Makarov, V.N., and Vasil'eva, T.N., Zh. Prikl. Khim. (St. Petersburg), 2000, vol. 73, p. 425.
Chanturiya, V.A., Makarov, V.N., Makarov, D.V., et al., Elektrokhimiya, 1999, vol. 35, p. 852.
Buckley, A.N., Hamilton, I.C., and Woods, R., Proc. 2nd Int. Symp. on Electrochemistry in Mineral and Metal Processing, Richardson, P.E., Srinivasan, S., and Woods, R., Eds., Pennington: The Electrochemical Society, 1984, p. 259.
Buckley, A.N., Hamilton, I.C., and Woods, R., Flotation of Sulphide Minerals, Føssberg, K.S.E., Ed., Amsterdam: Elsevier, 1985, p. 41.
Buckley, A.N. and Woods, R., Appl. Surf. Sci., 1985, vol. 20, p. 472.
Buckley, A.N. and Woods, R., Appl. Surf. Sci., 1985, vol. 22/23, p. 280.
Timoshenko, E.M., Sobol', S.I., Nagornaya, T.V., and Morozova, V.A., Tsvetn. Met. (Moscow), 1991, no. 11, p. 17.
Jones, C.F., LeCount, S., Smart, R., and White, T.J., Appl. Surf. Sci., 1992, vol. 55, p. 65.
Mikhlin, Yu.L., Tomashevich, E.V., Varnek, V.A., and Asanov, I.P., Zh. Neorg. Khim., 1995, vol. 40, p. 1247.
Mikhlin, Yu.L., Tomashevich, Ye.V., Pashkov, G.L., et al., Appl. Surf. Sci., 1998, vol. 125, p. 73.
Pratt, A.R., Nesbitt, H.W., and Muir, I.J., Geochim. Cosmochim. Acta, 1994, vol. 58, p. 5147.
Pratt, A.R. and Nesbitt, H.W., Am. J. Sci., 1997, vol. 297, p. 807.
Mikhlin, Yu., Varnek, V., Asanov, I., et al., Phys. Chem. Chem. Phys., 2000, vol. 2, p. 4393.
Thomas, J.E., Jones, C.F., Skinner, W.M., et al., Geochim. Cosmochim. Acta, 1998, vol. 62, p. 1555.
Thomas, J., Smart, R., and Skinner, W., Miner. Eng., 2000, vol. 13, p. 1149.
Mikhlin, Yu., Phys. Chem. Chem. Phys., 2000, vol. 2, p. 5672.
Practical Surface Analysis by Auger and X-ray Photoelectron Spectroscopy, Briggs, D. and Seah, M.P., Eds., New York: Wiley, 1983.
Pratt, A.R., Muir, I.J., and Nesbitt, H.W., Geochim. Cosmochim. Acta, 1994, vol. 58, p. 827.
Mott, N. and Davis, E., Electronic Processes in Non-Crystalline Materials, Oxford: Oxford Univ. Press, 1979. Translated under the title Elektronnye protsessy v nekristallicheskikh veshchestvakh, Moscow: Mir, 1982.
Kastner, M. and Fritzsche, H., Philos. Mag., 1978, vol. 37, p. 199.
Elektronnye yavleniya v khal'kogenidnykh stekloobraznykh poluprovodnikakh (Electronic Phenomena in Chalcogenide Vitreous Semiconductors), Tsendin, K.D., Ed., St. Petersburg: Nauka, 1996.
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Kuklinskii, A.V., Mikhlin, Y.L., Pashkov, G.L. et al. Conditions for the Formation of a Nonequilibrium Nonstoichiometric Layer on Pyrrhotite in Acid Solutions. Russian Journal of Electrochemistry 37, 1269–1276 (2001). https://doi.org/10.1023/A:1013231612008
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DOI: https://doi.org/10.1023/A:1013231612008