Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-27T22:28:51.464Z Has data issue: false hasContentIssue false

An investigation of extreme silver enrichment at tennantite surfaces exposed to alkaline solutions: an XPS-based study

Published online by Cambridge University Press:  05 July 2018

P. Wincott
Affiliation:
School of Earth, Atmospheric and Environmental Sciences, and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Oxford Road, Manchester M13 9PL, UK
D. J. Vaughan
Affiliation:
School of Earth, Atmospheric and Environmental Sciences, and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Oxford Road, Manchester M13 9PL, UK
R. A. D. Pattrick
Affiliation:
School of Earth, Atmospheric and Environmental Sciences, and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Oxford Road, Manchester M13 9PL, UK

Abstract

Extreme silver enrichment at the surface of the complex sulphide, tennantite (ideal formula: Cu12As4S13), occurs following exposure to alkaline solutions, and involves the development of an Ag-rich sulphide surface species. The tennantite has a low bulk Ag content of 0.3 at.%, and a percentage surface enrichment of Ag is thirty-six times that of the bulk. The techniques of X-ray photoelectron spectroscopy (XPS) and reflection extended X-ray absorption fine structure spectroscopy show the new phase to be a Ag sulphide species compositionally similar to cupriferous proustite ((Cu,Ag)3AsS3). Solution experiments and XPS depth profiling show that the surface is most depleted in Cu and Zn, and enriched in Ag compared to the bulk tennantite. Selective dissolution and reprecipitation at the tennantite surface cannot explain the enrichment of Ag relative to the bulk. Migration must have occurred and could have been driven by the leaching out of Cu which produces a metal-depleted surface, coupled to the relative incompatibility of Ag in the tennantite lattice. To account for the extreme enrichment at the surface, Ag must have diffused from depths of up to 9 nm, probably via structural weaknesses and vacancies in the tennantite lattice.

Type
Editorial
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2006

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

Ásbjörnsson, J., Kelsall, G. H., Pattrick, R. A. D., Vaughan, D. J., Wincott, P. L. and Hope, G. A. (2004) Electrochemical and surface analytical studies of enargite in acid solution. Journal of the Electrochemical Society, 151, 250256.CrossRefGoogle Scholar
Balaz, P., Ficeriova, J., Sepelak, V. and Kammel, R. (1996) Thiourea leaching of silver from mechanically activated tetrahedrite. Hydrometallurgy, 43, 367377.CrossRefGoogle Scholar
Balaz, P., Achimovcova, M., Ficeriova, J., Kammel, R. and Sepelak, V. (1998) Leaching of antimony and mercury from mechanically activated tetrahedrite Cu12Sb4S13 . Hydrometallurgy, 47, 297307.CrossRefGoogle Scholar
Balaz, P., Ficeriova, J. and Villachica, C. L. (2003) Silver leaching from mechanochemically pretreated complex sulfide concentrate. Hydrometallurgy, 70, 113119.CrossRefGoogle Scholar
Buckley, A. N. and Woods, R. (1983) An X-ray photoelectron spectroscopic investigation of the tarnishing of bornite. Australian Journal of Chemistry, 36, 1793–804.CrossRefGoogle Scholar
Buckley, A. N. and Woods, R. (1984) An X-ray photoelectron spectroscopic study of the oxidation of galena. Applications of Surface Science, 17, 401414.CrossRefGoogle Scholar
Buckley, A. N., Hamilton, I. C. and Woods, R. (1984) Investigation of the surface oxidation of bornite by linear potential sweep voltammetry and X-ray photoelectron spectroscopy. Journal of Applied Electrochemistry,, 14, 6374.CrossRefGoogle Scholar
Buckley, A. N., Hamilton, I. C. and Woods, R. (1985) Investigation of the surface oxidation of sulfide minerals by linear potential sweep voltammetry and X-ray photoelectron spectroscopy. Developments in Mineral Processing, 6, 4160.Google Scholar
Buckley, A. N., Woods, R. and Woutherlood, H. J. (1989) An XPS investigation of the surface of natural sphalerites under flotation-related conditions. International Journal of Mineral Processing, 26, 2949.CrossRefGoogle Scholar
Charlat, M. and Levy, C. (1974) Multiple substitutions in the tennantite–tetrahedrite series. Bulletin de la Societe franqaise de Mineralogie et de Cristallographie, 97, 241250.Google Scholar
Charnock, J. M., Garner, C. D., Pattrick, R. A. D. and Vaughan, D. J. (1989) Coordination sites of metals in tetrahedrite minerals determined by EXAFS. Journal of Solid State Chemistry, 82, 279289.CrossRefGoogle Scholar
Cordova, R., Gomez, H., Real, S. G., Schrebler, R. and Vilche, J. R. (1997) Characterization of natural enargite aqueous solution systems by electrochemical technique. Journal of the Electrochemical Society, 144, 26282636.CrossRefGoogle Scholar
Dutrizac, J. E., MacDonald, R. J. and Ingraham, T. R. (1970) Kinetics of dissolution of bornite in acidified ferric sulfate solutions. Metallurgical Transitions, 1, 225.Google Scholar
Ebel, D. S. and Sack, R. O. (1994) Experimental determination of the free energy of formation of freibergite fahlore. Geochimica et Cosmochimica Ada, 58, 12371242.CrossRefGoogle Scholar
Ficeriova, J., Balaz, P. and Boldizarova, E. (2005) Combined mechanochemical and thiosulphate leaching of silver from a complex sulphide concentrate. International Journal of Mineral Processing, 76, 260265.CrossRefGoogle Scholar
Fullston, D., Fornasiero, D. and Ralston, J. (1999a) Oxidation of synthetic and natural samples of enargite and tennantite: 1. Dissolution and zeta potential study. Langmuir, 15, 45244529.CrossRefGoogle Scholar
Fullston, D., Fornasiero, D. and Ralston, J. (1999b) Oxidation of synthetic and natural samples of enargite and tennantite: 2. X-ray photoelectron spectroscopic study. Langmuir, 15, 45304536.CrossRefGoogle Scholar
Gaarenstroom, S. W. and Winograd, N. (1977) Initial and final-state effects in ESCA spectra of cadmium and silver oxides. Journal of Chemical Physics, 67, 35003506.CrossRefGoogle Scholar
Ghosal, S. and Sack, R. O. (1995) As-Sb energetics in argentian sulfosalts. Geochimica et Cosmochimica Ada, 59, 35733579.CrossRefGoogle Scholar
Harlov, D. E. and Sack, R. O. (1995) Thermochemistry of Ag2S-Cu2S sulfide solutions: Constraints derived from coexisting Sb2S3- and As2S3- bearing sulfosalts. Geochimica et Cosmochimica Ada, 59, 43514365.CrossRefGoogle Scholar
Hellmann, R. M., Hervig, R. L., Thomassin, J. H. and Abrioux, M. F. (2003) An EFTEM/HRTEM high-resolution study of the near surface of labradorite feldspar altered at acid pH: evidence for interfacial dissolution-reprecipitation. Physics and Chemistry of Minerals, 30, 192197.CrossRefGoogle Scholar
Ixer, R. A. and Pattrick, R. A. D. (2003) Copper-arsenic ores and Bronze Age mining and metallurgy with special reference to the British Isles. Pp. 920 in: Mining and Metal Production through the Ages (Craddock, P. and Lang, J., editors). British Museum Press, London.Google Scholar
Johnson, M. L. and Burnham, C. W. (1985) Crystal structure refinement of an arsenic-bearing argentian tetrahedrite. American Mineralogist, 70, 165170.Google Scholar
Johnson, N. E., Craig, J. R. and Rimstidt, J. D. (1988) Crystal chemistry of tetrahedrite. American Mineralogist, 73, 389397.Google Scholar
Keith, C. (2002) Computer simulation studies of selected minerals of environmental significance. PhD Thesis, University of Manchester, UK.Google Scholar
Labotka, T. C., Cole, D. R., Fayek, M., Riciputi, L. R. and Stadermann, F. J. (2004) Coupled cation and oxygen-isotope exchange between alkali feldspar and aqueous chloride solution. American Mineralogist, 89, 18221825.CrossRefGoogle Scholar
Lascelles, D., Sui, C. C., Finch, J. A. and Butler, I. S. (2001) Copper ion mobility in sphalerite activation. Colloids and Surfaces A – Physicochemical and Engineering Aspects, 186, 163172.Google Scholar
Losch, W. and Monhemius, A. J. (1976) An AES study of copper-iron sulfide mineral. Surface Science, 60, 196210.CrossRefGoogle Scholar
Mielczarski, J. A., Cases, J. M., Alnot, M. and Ehrhardt, J. J. (1996a) XPS characterisation of chalcopyrite, tetrahedrite and tennantite surface products after different conditioning. 1. Aqueous solution at pH10 . Langmuir, 12, 25192530.CrossRefGoogle Scholar
Mielczarski, J. A., Cases, J. M., Alnot, M. and Ehrhardt, J. J. (1996b) XPS characterization of chalcopyrite, tetrahedrite, and tennantite surface products after different conditioning. 1. Amyl xanthate solution at pH 10. Langmuir, 12, 25312543.CrossRefGoogle Scholar
Moulder, J. F., Stickle, W. F., Sobol, P. E. and Bomben, K. D. (1992) Handbook of X-ray Photoelectron Spectroscopy. Perkin-Elmer Corporation, USA.Google Scholar
Pattrick, R. A. D. and Hall, A. J. (1983) Silver substitution onto synthetic zinc, cadmium and iron tetrahedrites. Mineralogical Magazine, 47, 441451.CrossRefGoogle Scholar
Pattrick, R. A. D., England, K. E. R., Charnock, J. M. and Mosselmans, J. F. W. (1999) Copper activation of sphalerite and its reaction with xanthate in relation to flotation: an X-ray absorption spectroscopy (reflection extended X-ray absorption fine structure) investigation. International Journal of Mineral Processing, 55, 247265.CrossRefGoogle Scholar
Pauling, L. and Neumann, E. W. (1934) The crystal structure of binnite (Cu, Fe)12As4S13 and the chemical composition and structure of minerals of the tetrahedrite group. Zeitschrift für Kristallographie, 88, 5462.Google Scholar
Pauporte, T. and Schuhmann, D. (1996) An electrochemical study of natural enargite under conditions relating to those used in flotation of sulphide minerals. Colloids Surfaces A – Physicochemical and Engineering Aspects, 111, 119.CrossRefGoogle Scholar
Peters, E. (1977) Electrochemistry of sulfide minerals. Pp. 267290 in: Trends in Electrochemistry (O'M Bockris, J, Rand, D. A. J., and Welch, B. J., editors). Plenum Press, New York.Google Scholar
Polya, D. A. (1998) PHOX: Automated calculation of mineral stability and aqueous species predominance fields in Eh (or log (fo(2)) or P epsilon)-pH space. Water-Rock Interaction, 897-900.Google Scholar
Pratesi, G. and Cipriani, C. (2000) Selective depth analysis of the alteration products of bornite, chalcopyrite and pyrite performed by XPS, AES, RBS. European Journal of Mineralogy, 12, 397409.CrossRefGoogle Scholar
Putnis, A. (2002) Mineral replacement reactions: from macroscopic observations to microscopic mechanisms. Mineralogical Magazine, 66, 689708.CrossRefGoogle Scholar
Sack, R. O. (2000) Internally consistent database for sulfides and sulfosalts in the system Ag2S-Cu2S-ZnS-FeS-Sb2S3-As2S3 . Geochimica et Cosmochimica Ada, 64, 38033812.CrossRefGoogle Scholar
Sack, R. O. (2005) Internally consistent database for sulfides and sulfosalts in the system Ag2S-Cu2S-ZnS-FeS-Sb2S3-As2S3: Update. Geochimica et Cosmochimica Acta, 69, 11571164.CrossRefGoogle Scholar
Shannon, R. D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, A32, 751767.CrossRefGoogle Scholar
Shannon, R. D. and Prewitt, C. T. (1970) Revised values of effective ionic radii. Acta Crystallographica, B26, 10461048.CrossRefGoogle Scholar
Shirley, D. A. (1972) High-resolution X-ray photoemis-sion spectrum of the valence bands of gold. Physics Review B, 5, 47094714.CrossRefGoogle Scholar
Tarasevich, M. R., Kudaikulova, G. A. and Radyushkina, K. A. (2000) Electroreduction of oxygen on copper-containing sulfide minerals. Russian Journal of Electrochemistry, 36, 4953.CrossRefGoogle Scholar
Ugarte, F. J. and Burkin, A. R. (1975) Mechanism of the formation of idaite from bornite by leaching with ferric sulfate solution. Pp. 46–53 in: Leaching and Reduction in Hydrometallurgy (Burkin, A. R., editor). Institution of Mining and Metallurgy, London.Google Scholar
Velasquez, P., Ramos-Barrado, J. R., Cordova, R. and Leinen, D. (2000a) XPS analysis of an electro-chemically modified electrode surface of natural enargite. Surface Interface Analysis, 30, 149153.3.0.CO;2-3>CrossRefGoogle Scholar
Velasquez, P., Leinen, D., Pascual, P., Ramos-Barrado, J. R., Cordova, R., Gomez, H. and Schrebler, R. (2000b) SEM, EDX and EIS study of an electro-chemically modified electrode surface of natural enargite (Cu3AsS4). Journal of Electroanalytical Chemistry, 494, 8795.CrossRefGoogle Scholar
Wagner, T., Boyce, A. and Fallick, A. (2002) Laser combustion analysis of δ34S of sulfosalt minerals: Determining the fractionation systematics and some crystal-chemical considerations. Geochimica et Cosmochimica Acta, 66, 28552863.CrossRefGoogle Scholar
Wills, B. A. (1997) Mineral Processing Technology, 6thedition. Butterworth-Heinemann, Oxford, UK.Google Scholar
Wuensch, B. J. (1964) The crystal structure of tetra-hedrite, Cui2Sb4Si3 . Zeitschrift für Kristallographie, 119, 437453.CrossRefGoogle Scholar