The System Pd-Fe-Ni-S at 900 and 725°C

Emil Makovicky and Sven Karup-Møller
Department of Mineralogy, Geological Institute, University of Copenhagen, 1350 Copenhagen, Denmark
Institute of Mineral Industry, Technical University of Denmark, 2800 Lyngby, Denmark

Abstract: The system Pd-Fe-Ni-S was studied at 900 and 725°C by means of dry condensed charges. At both temperatures it is dominated by the phase relationships involving sulphide melt. Pd-Fe-Ni alloys with broad miscibility primarily coexist with the melt; they are relatively enriched in Pd, whereas the associated melt is enriched in Ni. With decreasing temperature the melt recedes from Fe-rich regions. The incompatibility of PdS (extensive solid solution with Ni) and mss at 900°C is replaced by their co-crystallization (± disulphide(s) of Ni,Fe or ± sulphide melt) at 725°C The Ni/Fe ratio in the melt changes regularly against that in mss with increasing S fugacity and Pd contents in these two phases. (Ni,Fe)xS2 and Pd4S play important roles at 725°C. The data offer an array of distribution coefficients and solubility values suitable for geological interpretations.

Keywords: Pd-Fe-Ni-S system • platinum-group elements • palladium • sulphide melt

Mineralogical Magazine; December 1995 v. 59; no. 397; p. 685-702; DOI: 10.1180/minmag.1995.059.397.11
© 1995, The Mineralogical Society
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