TY - JOUR

T1 - Crystallization of pyrrhotite from Fe-Ni-Cu-S-(Rh, Ru) melt

AU - Sinyakova, E. F.

AU - Komarov, V. Yu

AU - Sopov, K. V.

AU - Kosyakov, V. I.

AU - Kokh, K. A.

N1 - Publisher Copyright: © 2020 Elsevier B.V. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/10/15

Y1 - 2020/10/15

N2 - We have studied the composition and structure of the products of initial crystallization stage of melt with the following composition (in mol. %): Fe 31.90, Cu 16.03, Ni 1.70, S 50.31, and by 0.03 Ru and Rh. Directional solidification of the sample was carried out in the region of primary crystallization of pyrrhotite solid solution (Poss) in the Fe-Cu-Ni-S system. Results of optical microscopy and SEM-EDS showed that the distribution of the main components and Rh in the sample agrees with the theory of directed crystallization. Refractory ruthenium sulfide RuS2 (structure type FeS2, pyrite), formed in the sulfide melt, plays the part of mechanical dopant. On cooling of the crystallized sample, Poss partly decomposes to form nonstoichiometric isocubanite Cu1.1Fe2S3 (Icb*). On further cooling, Icb* decomposes into stoichiometric isocubanite CuFe2S3 (Icb) and Cu3Fe4S7 phase. These phase reactions do not influence the distribution of Rh and Ru in the sample volume. Crystallographic parameters, features of modulation and spatial orientation of pyrrhotite and cubanite phases of sulfide matrix were determined.

AB - We have studied the composition and structure of the products of initial crystallization stage of melt with the following composition (in mol. %): Fe 31.90, Cu 16.03, Ni 1.70, S 50.31, and by 0.03 Ru and Rh. Directional solidification of the sample was carried out in the region of primary crystallization of pyrrhotite solid solution (Poss) in the Fe-Cu-Ni-S system. Results of optical microscopy and SEM-EDS showed that the distribution of the main components and Rh in the sample agrees with the theory of directed crystallization. Refractory ruthenium sulfide RuS2 (structure type FeS2, pyrite), formed in the sulfide melt, plays the part of mechanical dopant. On cooling of the crystallized sample, Poss partly decomposes to form nonstoichiometric isocubanite Cu1.1Fe2S3 (Icb*). On further cooling, Icb* decomposes into stoichiometric isocubanite CuFe2S3 (Icb) and Cu3Fe4S7 phase. These phase reactions do not influence the distribution of Rh and Ru in the sample volume. Crystallographic parameters, features of modulation and spatial orientation of pyrrhotite and cubanite phases of sulfide matrix were determined.

KW - A1. 3D reciprocal space analysis

KW - A1. Directional solidification

KW - A1. High-resolution powder XRD

KW - B1. Cu-Fe-Ni-S-(Rh, Ru) system

KW - B1. Pyrrhotite solid solution

KW - SYSTEM

KW - PALLADIUM

KW - MONOSULFIDE SOLID-SOLUTION

KW - Directional solidification

KW - CUBANITE

KW - Pyrrhotite solid solution

KW - High-resolution powder XRD

KW - CU-FE-S

KW - 3D reciprocal space analysis

KW - SULFIDE LIQUID

KW - PLATINUM-GROUP ELEMENTS

KW - FRACTIONAL CRYSTALLIZATION

KW - PHASE-RELATIONS

KW - NI

KW - Cu Fe Ni S (Rh, Ru) system

UR - http://www.scopus.com/inward/record.url?scp=85088921945&partnerID=8YFLogxK

U2 - 10.1016/j.jcrysgro.2020.125822

DO - 10.1016/j.jcrysgro.2020.125822

M3 - Article

AN - SCOPUS:85088921945

VL - 548

JO - Journal of Crystal Growth

JF - Journal of Crystal Growth

SN - 0022-0248

M1 - 125822

ER -