Behavior of components of melts similar in composition nickel concentrate and nickel matte at directed crystallization

The results of a study on the behavior of macrocomponents and admixtures at directed crystallization of two specimens of the Fe-Ni-S (Pt, Pd) system are presented in this paper. The composition of the specimens belonged to the areas of primary crystallization of a monosulphide solid solution ((Fe _z Ni_{1 − z} )S_{1 + δ}) and taenite (Fe-Ni solid solution with the structure γ-Fe), which were similar in composition to nickel concentrate and nickel matte from the Norilsk Mining and Metallurgical Company (MMC). In this paper, data on the component distribution along the crystallized specimens are given, and the dependence of the component distribution coefficients on the melt composition along the crystallization path is determined. The conditions under which one-phased crystallization becomes the crystallization of binary eutectics and then transforms to a four-phased invariant reaction are also determined. Some bounds of the possibility to use crystallization processes for the separation of phases and components in the investigated system in a quasi-equilibrium regime of specimen solidification are analyzed.