Construction of phase diagram in systems Na2СO3·10H2O – CH3COONa·3H2O

Abstract

The phase diagram in the system of crystalline hydrates Na2CO3·10H2O – CH3COONa·3H2O is constructed with methods of thermal analysis, this diagram is of the eutectic type. Eutectic composition is 66 wt.% Na2CO3·10H2O + 34 wt.% CH3COONa·3H2O. Eutectic temperature is of –11±0.7 °C. The enthalpy of melting and crystallization of mixtures relatively to liquidus and solidus lines were measured, which were used for specify the type of phase diagrams. As the eutectic composition is approached, the reduction of supercooling was established. The mixture of eutectic composition was proposed for using as a heat storage material.