Differentiation of the Multicomponent System Na,K,Sr∥Cl,NO3: Phase Diagram and Physicochemical Properties of Salt Mixtures in the System NaNO3—NaCl—KNO3—Sr(NO3)2

Abstract

The differentiation of the quaternary reciprocal system Na,K,Sr∥Cl,NO₃ was performed based on graph theory using special software. Stable and metastable complexes of the system were found using a matrix of reciprocal pairs of salts. For the first time, by physicochemical analysis methods (differential thermal, visual polythermal, and X-ray powder diffraction analyses using the method of thermal analysis of successive projections of the composition polytope), the quaternary system NaNO₃-NaCl-KNO₃-Sr(NO₃)₂, which is a stable complex of the quaternary reciprocal system Li,Ca,Ba∥F,WO₄, was studied and the coordinates of invariant points were determined. The density and electrical conductivity were determined, volumetric changes were calculated, and the corrosion of 12Kh18N10T steel in eutectic and peritectic salt mixtures was investigated.