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.