BEHAVIOR OF PGM IMPURITIES ON CRYSTALLIZATION OF MELTS OF THE Fe-Ni-S SYSTEM (FexNi0,49-xS0,51)
E. F. Sinyakova, V. I. Kosyakov, and G. R. Kolonin
Keywords: Fe-Ni-S system, platinum, iridium, light platinoids, monosulfide solid solution, sulfide melt, partition coefficients
Pages: 1354-1370
Abstract
Experiments have revealed the main tendencies of the physicochemical behavior of Ni, Fe, and PGM impurities at an early stage of crystallization of Fe-Ni sulfide melts with a small surplus of sulfur relative to the total of metals. It has been shown that crystallization of sulfide melts of the section Fe xNi 0,49-xS 0,51 occurs at 900 oC throughout the interval of ratios Ni/(Ni + Fe) with the formation of a monosulfide solid solution (mss) as the main phase, Fe being fractionated chiefly into mss and Ni, into the melt. Against this background, under certain conditions PGE-bearing phases can form – (Pt, Fe, Ir)-alloy (at initial  Ni), RuS 2 (at initial Ni > Fe), (Pt, Ni)S – in a specimen of pure Ni initial composition, i.e., at the ultimately high value of lg f(S 2) = |
