Partition of the Quaternary Reciprocal System Na,K∥Cl,I,CrO4 and Investigation of Its Stable Elements

Abstract

Investigation of multicomponent salt systems is important in the context of the wide use of invariant mixtures as electrolytic media for separation of metals and heat-storage materials. In this work, the quaternary reciprocal system Na,K∥Cl,I,CrO₄ was partitioned into simplexes using graph theory. The tree of phases of the system was constructed, and stable elements were determined. The stable tetrahedron NaCl–KCl–KI–K₂CrO₄ of the system Na,K∥Cl,I,CrO₄ was studied by differential thermal analysis. In the stable tetrahedron, the melting point and composition (equiv. %) of a quaternary eutectic were found: (0.25% KCl, 42.40% NaCl, 30.92% KI, 26.43% K₂CrO₄; 451°C).