ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Experimental-determination and thermodynamic analysis of the phase-diagrams of the systems NaCl-Na₂SO₄ and NaCl -NaF

J. Gabčová and M. Malinovský

Department of Chemical Technology of Inorganic Substances, Slovak Technical University, CS-812 37 Bratislava

Abstract: Phase diagrams of the systems NaCI—Na₂SO₄ and NaCI—NaF were experi­mentally investigated using the thermal analytical method. It was found that both systems probably have a simple eutectic character. However, in the case of the system NaCI—NaF existence of a narrow range of solid solutions formed on the base of NaCI cannot be excluded."Coordinates of the eutectic point in the system NaCI—Na₂SO₄ are following: 54.0 mole % NaCI, 46.0 mole % Na₂SO₄ ; T(E) = 901 K. Coordinates of the eutectic point in the system NaCI—NaF are: 66.0 mole % NaCI, 34.0 mole % NaF; T(E) = 955 K. Experimental data were treated by thermodynamic analysis. The 1st and the 2nd criterion of thermodynamic consistency were applied. The activity coef­ficients, the parameter b in the universal relationship, the parameter w in the relationship valid for true regular solutions and the excess Gibbs energies of components were determined.

Full paper in Portable Document Format: 402a201.pdf

Chemical Papers 40 (2) 201–213 (1986)