Hostname: page-component-5db58dd55d-f6s65 Total loading time: 0 Render date: 2026-06-01T13:38:06.220Z Has data issue: false hasContentIssue false
  • English
  • Français

Phase relations in the metal-rich portions of the phase system Pt-Ir-Fe-S at 1000°C and 1100°C

Published online by Cambridge University Press:  05 July 2018

E. Makovicky  and
S. Karup-Møller
E. Makovicky*
Affiliation:
Department of Mineralogy, Geological Institute, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark
S. Karup-Møller
Affiliation:
Institute for Geology and Geological Engineering, The Danish Technical University, Building 205, DK-2800 Lyngby, Denmark
*
*E-mail: emilm@geo.geol.ku.dk
Get access Rights & Permissions [Opens in a new window]

Abstract

Phase relations in the S-poor portions of the dry condensed Pt-Ir-Fe-S system were determined at 1000° and 1100°C with a particular emphasis on delineation of the solid solubility fields of the Pt-Ir-Fe alloys. At both temperatures, a broad field of γ(Ir,Fe,Pt) alloy coexists with γ-(Pt,Fe), Pt3Fe and PtFe which dissolve respectively at least 5.1, 29.3 and 24.0 at.% Ir at 1100°C (2.2, 23.6 and ≤17.2 at.% Ir at 1000°C). Gaps between the nearly Ir-free Pt-Fe alloys γ(Pt,Fe), Pt3Fe s.s., PtFe s.s. and γ(Fe,Pt) were estimated as 20–23 at.%, 40–42 at.% and 54.2–~57 at.% Fe at 1100°C (18–23, 39.5–42.5 and 59–62 at.% Fe at 1000°C). The first gap agrees with data from natural phases by Cabri et al. (1996). The Fe-rich sulphide melt dissolves only traces of Pt and Ir; Fe1–x S dissolves up to 5.8 at.% Ir at 1100°C and 3.4 at.% Ir at 1000°C. These solubilities and the compositions of coexisting alloys (before low-temperature exsolution) may serve as geothermometers. The S-rich melt dissolves up to 8.2 at.% Pt and 2.5 at.% Ir (measured on a solidified melt) at 1100°C. The Fe-Ir thiospinel dissolves up to 2.2 at.% Pt (for the composition Fe21.6Ir18.9Pt2.2S57.3 at 1100°C). The 25–28 at.% Fe portions of Pt3Fe with <10 at.% Ir partake in all important sulphide (± melt)-alloy assemblages (with PtS, Ir2S3, pyrrhotite, S-rich melt and thiospinel). Therefore, their use in recognizing distinct natural assemblages of genetic importance is of limited value.

Keywords

Pt-Ir-Fe-S phase systemPt-Fe alloysisoferroplatinumtetraferroplatinumplatinum-groupmetal deposits

Information

Type
Research Article
Information
Mineralogical Magazine , Volume 64 , Issue 6 , December 2000 , pp. 1047 - 1056
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

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.)

Article purchase

Temporarily unavailable

References

Augé, T. and Legendre, O. (1992) Pt-Fe nuggets from alluvial deposits in Eastern Madagascar. Canad. Mineral., 30, 983-1004.Google Scholar
Bowles, J.F.W. (1990) Platinum-iron alloys, their structural and magnetic characteristics in relation to hydrothermal and low-temperature genesis. Mineral. Petrol., 43, 37-47.CrossRefGoogle Scholar
Bryukvin, V.A., Fishman, B.A., Reznichenko, V.A., Shekter, L.N., Blokhina, L.I. and Kukoyev, V.A. (1987) Studies on the phase diagram of the Fe-Pt-S system. Izvestiya ANSSSR Metally No. 4, 25-30 (in Russian).Google Scholar
Cabri, L.J. (1982) Classification of platinum-group element deposits with reference to the Canadian Cordillera. Pp. 21-31 in: Proc. Conf. Precious Metals in the Northern Cordillera (Levinson, A.A., editor). Association of Exploration Geochemists, Canada.Google Scholar
Cabri, L.J. and Feather, C.E. (1975) Platinum-iron alloys: a nomenclature based on a study of natural and synthetic alloys. Canad. Mineral., 13, 117–26.Google Scholar
Cabri, L.J. and Hey, M.H. (1974) Platiniridium – confirmation as a valid mineral species. Canad. Mineral., 12, 299-303.Google Scholar
Cabri, L.J. and Laflamme, J.M.G. (1981) Analyses of minerals containing platinum-group elements. Pp. 151–73 in: Platinum-Group Elements: Mineralogy, Geology, Recovery (Cabri, L.J., editor). Canadian Institute of Mining and Metallurgy, Spec. Vol. 23.Google Scholar
Cabri, L.J., Criddle, A.J., Laflamme, J.M.G., Bearne, G.S. and Harris, D.C. (1981) Mineralogical study of complex Pt-Fe nuggets from Ethiopia. Bull. Mineral., 104, 508–25.Google Scholar
Cabri, L.J., Harris, D.C. and Weiser, T.W. (1996) Mineralogy and distribution of platinum-group mineral (PGM) placer deposits of the world. Exploration and Mining Geology, 5, 73–167.Google Scholar
Dill, J.A., Skinner, B.J., Luce, F.D. et al. (1976) Phase relations in ternary portions of the system Pt-Pd-Fe-As-S. Econ. Geol., 71, 1469–75.Google Scholar
Dmitrenko, G.G. (1994) Platinum Group Minerals of Alpine-type Ultramafics. Far-Eastern Branch of the Russian Academy of Sciences, Northea stern Interdisciplinary Research Institute, Magadan, 134 pp. (in Russian).Google Scholar
Fishman, B.A., Pavlyuchenko, N.M., Blagoveshchenskaya, N.V., Bryukvin, V.A., Blokhina, L.I. and Byalyi, A.V. (1992) Study of eutectic equilibrium in the Os-S and Ir-S systems. Izv. Russ. Akad. Nauk, Metally, No. 4, 51–4 (in Russian).Google Scholar
Johan, Z. (1995) Minéralogie des platinoides: implications génétiques. Colloque Minéralogie Fondamentale et Appliquée à la memoire de Claude Guillemin. Résumés des Communications. Documents du B.R.G.M., 243, 37-41.Google Scholar
Johan, Z., Ohnenstetter, M., Slansky, E., Barron, L.M. and Suppel, D. (1989) Platinum mineralization in the Alaskan-type intrusive complexes near Fifield, New South Wales, Australia. Part 1. Platinum-group minerals in clino-pyroxenites of the Kelvin Grove Prospect, Owendale intrusion. Mineral. Petrol., 40, 289–309.CrossRefGoogle Scholar
Johan, Z., Ohnenstetter, M., Fischer, W. and Amossé, J. (1990) Platinum-group minerals from the Durance river alluvium, France. Mineral. Petrol., 42, 287-306.CrossRefGoogle Scholar
Kubaschewski, O. (1982) Iron-Binary Phase Diagrams. Springer, New York, Berlin.Google Scholar
Majzlan, J., Makovicky, M., Makovicky, E. and Rose-Hansen, J. (2000) The phase system Fe-Pt-S at 1100°C. Canad. Mineral. (in press).Google Scholar
Makovicky, E. and Karup-Møller, S. (1999) The phase system Fe-Ir-S at 1100°C, 1000°C, and 800°C. Mineral. Mag., 63, 379–85.CrossRefGoogle Scholar
Makovicky, M., Makovicky, E. and Rose-Hansen, J. (1988) Experimental evidence on the formation and mineralogy of platinum and palladium ore deposits. Pp. 303–17 in: Mineral Deposits within the European Community (Boissonnas, J. and Omenetto, P., editors ). Springer-Verlag, Berlin-Heidelberg.CrossRefGoogle Scholar
Makovicky, M., Makovicky, E. and Rose-Hansen, J. (1992) The phase system Pt-Fe-As-S at 850°C and 470°C. Neues Jahrb. Mineral., Mh., H. 10, 441–53.Google Scholar
Massalski, T.B., Murray, J.L., Bennett, L.H. and Baker, H. (1986) Binary Alloy Phase Diagrams (Vol. 1). American Society of Metals, Ohio.Google Scholar
Mochalov, A.G. (1994) Mineral sequences of mineralogical-geochemical types of PGE placers (a base for local prediction). Geology and genesis of ore deposits of platinum group metals. Nauka (Moscow) (in Russian).Google Scholar
Nixon, G.T., Cabri, L.J. and Laflamme, J.M.G. (1990) Platinum-group-element mineralization in lode and placer deposits associated with the Tulameen Alaskan-type complex, British Columbia, Canad. Mineral., 28, 503–35.Google Scholar
Raghavan, V. (1988) Phase Diagrams of Ternary Iron Alloys. Part 2. Ternary Systems Containing Iron and Sulphur. The Indian Institute of Metals.Google Scholar
Raub, E. and Plate, W. (1956) Tempering and decomposition of platinum-iridium alloys. Zeits. Metallkunde, 47, 688–93.Google Scholar
Skinner, B.J., Luce, F.D., Dill, J.A., Ellis, D.E., Hagan, H.A., Lewis, D.M., Odell, D.A., Sverjensky, D.A. and Williams, N. (1976) Phase relations in ternary portion of the system Pt-Pd-Fe-As-S. Econ. Geol., 71, 1469–75.CrossRefGoogle Scholar
Slansky, E., Johan, Z., Ohnenstetter, M., Barron, L.M. and Suppel, D. (1991) Platinum mineralization in the Alaskan-type intrusive complexes near Fifield, N.S.W. Australia. Part 2. Platinum-group minerals in placer deposits at Fifield. Mineral. Petrol., 43, 161–80.CrossRefGoogle Scholar
Toma, S.A., and Murphy, S. (1977) The composition and properties of some native platinum concentrates from different localities. Canad. Mineral., 15, 59-69.Google Scholar