Treatment of Tunisian salt lakes using solubility phase diagrams

The Tunisian salt lakes are considered as an important materials resource u seful for industry and agriculture. They are called sebkhat or chott, and t hey cover a large part of Tunisian land. Their brines correspond to the qui nary system: Na+, K+ Mg2+ / Cl-, SO42--H2O. 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 equati ons used for modeling the quinary system are established and applied to the subsystems NaCl-KCl-H2O, NaCl-MgCl2-H2O, KCl-MgCl2-H2O, and to NaCl-Na2SO4 -H2O, KCl-K2SO4-H2O, Na2SO4-K2SO4-H2O. The coherence between the calculated and the experimental diagrams is discussed.