Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-15T19:19:10.276Z Has data issue: false hasContentIssue false

Surface oxidation studies of chalcopyrite and pyrite by glancing-angle X-ray absorption spectroscopy (REFLEXAFS)

Published online by Cambridge University Press:  05 July 2018

K. E. R. England
Affiliation:
Department of Earth Sciences, University of Manchester, Manchester M13 9PL, UK
J. M. Charnock
Affiliation:
Department of Earth Sciences, University of Manchester, Manchester M13 9PL, UK CCLRC Daresbury Laboratory, Warrington WA4 4AD, UK
R. A. D. Pattrick
Affiliation:
Department of Earth Sciences, University of Manchester, Manchester M13 9PL, UK
D. J. Vaughan
Affiliation:
Department of Earth Sciences, University of Manchester, Manchester M13 9PL, UK

Abstract

The oxidation of chalcopyrite and pyrite was examined using Fe-K- and Cu-K-edge REFLEXAFS spectroscopy. The Fe XANES of the pyrite proved to be a very sensitive indicator of oxidation, revealing the development of a goethite-like surface species; the EXAFS data showed an increasing O:S ratio with the degree of oxidation and gave Fe–O distances of c. 1.9 Å. On the oxidized chalcopyrite surfaces, the development of Fe-O and Cu-O species was observed, with both the XANES and EXAFS revealing the progressive development of these species with oxidation. Differences in the sensitivity of the XANES and EXAFS to the degree of oxidation can be related to the degree of long range order and changes in the intensity of the pre-edge feature of the Fe are a function of its oxidation state and coordination geometry in the surface species.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Biegler, T. and Horne, M.D. (1985) The electrochemistry of surface oxidation of chalcopyrite. J. Electrochem. Soc., 32, 1363–9.CrossRefGoogle Scholar
Biegler, T. and Swift, D.A. (1979) Anodic behaviour of pyrite in acid solutions. Electrochim. Acta, 24, 415–20.CrossRefGoogle Scholar
Binsted, N., Campbell, J.W., Gurman, S.J. and Stephenson, P.C. (1991) Daresbury Laboratory EXCURV92 program.Google Scholar
Cattarin, S., Flechter, S., Pettenkofer, C. and Tributsch, H. (1990) Interfacial reactivity and oscillating behavior of chalcopyrite cathodes during H2O2 reduction II. Characterisation of electrode corrosion. J. Electrochem. Soc., 137, 3484–93.CrossRefGoogle Scholar
Gardner, J.R. and Woods, R. (1979) An electrochemical investigation of the natural flotability of chalcopyrite. Int. J. Miner. Proc., 6, 116.CrossRefGoogle Scholar
Greaves, G.N. (1991) Glancing angle X-ray absorption spectroscopy. Advance. X-ray Anal., 34, 1322.Google Scholar
Greaves, G.N., Barrett, N.T., Antonini, G.M., Thornley, F.R., Willis, B.T.M. and Steel, A. (1989) Glancing-angle X-ray absorption spectroscopy of corroded borosilicate glass surfaces containing uranium. J. Amer. Chem. Soc., 111, 4313–24.CrossRefGoogle Scholar
Gurman, S.J., Binsted, N. and Ross, N. (1984) A rapid, exact, curved wave theory for EXAFS calculations. J. Phys. C, 17, 143–51.Google Scholar
Hedin, L. and Lundqvist, S. (1969) Effects of electron-electron and electron-phonon interactions on the one-electron states of solids. Solid State Phys., 23, 1181.Google Scholar
Henderson, C.M.B., Cressey, G. and Redfern, S.A.T. (1995) Geological applications of synchrotron radiation. Radiat. Phys. Chem., 45, 459–81.CrossRefGoogle Scholar
Joyner, R.W., Martin, K.J. and Meehan, P. (1987) Some applications of statistical tests in analysis of EXAFS, SEXAFS and XANES. J. Phys. C, 20, 4005–12.Google Scholar
Kelsall, G.H. and Page, P.W. (1984) Aspects of chalcopyrite (CuFeS2) electrochemistry. In. International Symposium on Electrochemistry in Mining and Metallurgy Process (Richardson, P.E. et al., eds), pp. 303–16. Electrochemical Society, New Jersey, USA.Google Scholar
Kelsall, G.H. Yin, Q., Vaughan, D.J. and England, K.E.R. (1996) Electrochemical oxidation of pyrite (FeS2) in acidic aqueous electrolytes I. In. International Symposium on Electrochemistry in Mineral and Metal Processing (Woods, R., Richardson, P.E. and Doyle, F.M., eds), 96-6, pp 131–42. Electrochemical Society, New Jersey, USA.Google Scholar
Koningsberger, D. and Prins, R. (eds) (1988) X-ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS and XANES. Wiley, New York.Google Scholar
Lowson, R.T. (1982) Aqueous oxidation of pyrite by molecular oxygen. Chem. Rev., 82, 461–97.CrossRefGoogle Scholar
McKibben, M.A. and Barnes, H.L. (1986) Oxidation of pyrite in low temperature acidic solutions: rate laws and surface textures. Geochim. Cosmochim. Acta, 50, 1509–20.CrossRefGoogle Scholar
McMillan, R.S., Mackinnon, D.J. and Dutriizac, J.E. (1982) Anodic dissolution of n-type and p-type chalcopyrite. J. Appl. Electrochem., 12, 743–57.CrossRefGoogle Scholar
Mishra, K.K. and Osseo-Asare, K. (1992) Fermi-level spinning at pyrite (FeS2)/electrolyte junctions. J. Electrochem. Soc., 139, 749–52.CrossRefGoogle Scholar
Moses, C.O. and Herman, J.S. (1991) Pyrite oxidation at circumneutral pH. Geochim. Cosmochim. Acta, 55, 471–82.CrossRefGoogle Scholar
Moses, C.O., Nordstrom, D.K., Herman, J.S. and Mills, A.L. (1987) Aqueous pyrite oxidation by dissolved oxygen and by ferric iron. Geochim. Cosmochim. Acta, 51, 1561–71.CrossRefGoogle Scholar
Mosselmans, J.F.W., Pattrick, R.A.D., van der Laan, G., Charnock, J.M., Vaughan, D.J., Henderson, C.M.B. and Garner, C.D. (1995) X-ray absorption near-edge spectra of transition metal disulfides FeS2 (pyrite and marcasite), CoS2, NiS2, and CuS2 and their isomorphs FeAsS and CoAsS. Phys. Chem. Mineral., 22, 311–7.CrossRefGoogle Scholar
Parker, A.J., Paul, P.L., and Power, G.P. (1981a) Electrochemical aspects of leaching copper from chalcopyrite in ferric and cupric salt solutions. Australian J. Chem., 34, 1334.CrossRefGoogle Scholar
Parker, A.J., Paul, P.L. and Power, G.P. (1981b) Electrochemistry of the oxidative leaching of copper from chalcopyrite. J. Electroanal. Chem., 118, 305–16.CrossRefGoogle Scholar
Tao, D.P., Li, Y.Q., Richardson, P.E. and Yoon, R.H. (1994) The incipient oxidation of pyrite. Colloids and Surfaces A. Physicochemical and Engineering Aspects, pp. 229–39. Elsevier Science Publications, The Netherlands.Google Scholar
Warren, G.W., Wadsworth, M.E., and El-Raghy, S.M. (1982) Passive and transpassive anodic behaviour of chalcopyrite in acid solutions. Met. Trans., B13, 571–9.CrossRefGoogle Scholar
Williamson, M.A. and Rimstidt, J.D. (1994) The kinetics and electrochemical rate-determining step of aqueous pyrite oxidation. Geochim. Cosmochim. Acta, 58, 5443–54.CrossRefGoogle Scholar
Yin, Q., Kelsall, G.H., Vaughan, D.J. and England, K.E.R. (1995) Atmospheric and electrochemical oxidation of the surface of chalcopyrite (CuFeS2). Geochim. Cosmochim. Acta, 59, 1091–100.CrossRefGoogle Scholar