Formation of Noble Metal Phases (Pt, Pd, Rh, Ru, Ir, Au, Ag) in the Process of Fractional Crystallization of the CuFeS2 Melt

Описание

Тип публикации: статья из журнала

Год издания: 2022

Идентификатор DOI: 10.3390/min12091136

Ключевые слова: cu-fe-s system, directional crystallization, fine inclusions, intermediate solid solution, noble metals

Аннотация: The quasi-equilibrium directional crystallization of the melt composition (at. %): Cu 24.998, Fe 25.001, S 49.983, with Ag 0.002, Pd 0.003, Ru 0.004, Rh 0.006, and Au, Pt, Ir (each as 0.001) was carried out. The crystallized cylindrical ingot consisted of two primary zones and three secondary zones with different chemical and phaseПоказать полностьюcompositions. The compositions of the primary zones corresponded to high-temperature intermediate solid solution (zone I) and liquid enriched in sulfur (zone II). The compositions of the secondary zones corresponded to low-temperature intermediate solid solution and chalcopyrite (zone Ia), the same intermediate solid solution with chalcopyrite and bornite (zone Ib), and again with bornite, chalcocite, and idaite (zone II). We plotted the distribution curves of Fe, Cu, and S along the ingot, calculated the distribution coefficients of the components during directional crystallization, and clearly showed that, from the initial stoichiometric composition CuFeS2, the intermediate solid solution enriched in Fe and depleted in S is crystallized. Based on the data of directional crystallization and thermal analysis, a cross section was constructed in the intermediate solid solution-sulfide melt region of the Cu-Fe-S system. With solubility in the solid Cu-Fe sulfides lying below detection limit of scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM/EDS), noble elements occurred as individual phases of a size more often <10 µm. They were identified as Ag, RuS2, PdS, Au* (an Au based alloy), (Rh, Ir, Ru)3S8, (Rh, Ir)3S8, Rh3S8, and (Cu, Fe)~2(Pt, Rh)1S~5 phases by electron microprobe. Based on ab initio calculations of crystal structure, electronic band structure, and lattice dynamics of idealized laurite RuS2 phase and the idealized Ir3S8, Rh3S8, and Ru3S8 phases, the interpretation of Raman spectrum of the cation-mixed (Ru, Rh, Ir)S2 sulfide was presented for the first time. © 2022 by the authors.

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Издание

Журнал: Minerals

Выпуск журнала: Vol. 12, Is. 9

Номера страниц: 1136

ISSN журнала: 2075163X

Издатель: MDPI

Персоны

  • Sinyakova E.F. (V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russian Federation)
  • Vasilyeva I.G. (Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Ac. Lavrentieva ave. 3, Novosibirsk, 630090, Russian Federation)
  • Oreshonkov A.S. (Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Akademgorodok 50/38, Krasnoyarsk, 660036, Russian Federation, School of Engineering and Construction, Siberian Federal University, Krasnoyarsk, 660041, Russian Federation)
  • Goryainov S.V. (V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russian Federation)
  • Karmanov N.S. (V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russian Federation)

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