Liquidus Topology of NaBr–Na2SO4–Na2CO3 and KBr–K2CO3–K2SO4 Systems

Abstract

A theoretical analysis is performed of the topology of the liquidus in the NaBr–Na2CO3–Na2SO4, KBr–K2CO3–K2SO4 systems. The coordinates of minimum point on the monovariant curve in the NaBr–Na2CO3–Na2SO4 system are calculated using the Martynova–Susarev approach. An experimental design is devised for studying systems via differential thermal analysis. The melting point and composition of the salt mixture corresponding to the minimum on the monovariant curve of the NaBr–Na2CO3–Na2SO4 system are determined. The absence of nonvariant equilibrium points in the KBr–K2CO3–K2SO4 system is proved. The NaBr–Na2CO3–Na2SO4, KBr–K2CO3–K2SO4 systems have yet to be studied. They are of interest, since their components have a number of valuable properties, e.g., thermal stability and the possibility of using them as solvents for some other salts over a wide range of temperatures.