Pure and Applied Chemistry

Abstract: The Tunisian salt lakes are considered as an important materials resource useful for industry and agriculture. They are called sebkhat or chott, and they cover a large part of Tunisian land. Their brines correspond to the quinary system: Na⁺, K⁺, Mg²⁺ / Cl­, SO₄²­­H₂O. In the first part of this paper, a short description and abstracted geochemical and economical data about some Tunisian salt lakes are given. In the second part, the fitting equations used for modeling the quinary system are established and applied to the subsystems NaCl­KCl­H₂O, NaCl­MgCl₂­H₂O, KCl­MgCl₂­H₂O, and to NaCl­Na₂SO₄­H₂ O, KCl­K₂SO₄­H₂ O, Na₂SO₄­K₂SO ₄­H₂O. The coherence between the calculated and the experimental diagrams is discussed.