Experimental and Thermodynamic Modeling Study of the Solid–Liquid Equilibria in the Quaternary System (LiCl + MgCl₂ + Li₂SO₄ + MgSO₄ + H₂O) at 288.15 K and 0.1 MPa

Abstract

Solid–liquid phase equilibria of the quaternary system (LiCl + MgCl2 + Li2SO4 + MgSO4 + H2O) at T = 288.15 K and p = 0.1 MPa were investigated using the isothermal dissolution equilibrium method, and a dry salt diagram and a water diagram were plotted accurately. The phase diagram of this quaternary system includes four invariant points, nine univariant solubility curves, and six crystallization regions corresponding to Li2SO4·H2O, LiCl·2H2O, LiCl·MgCl2·7H2O, MgCl2·6H2O, MgSO4·7H2O, and MgSO4·6H2O. The double salt of LiCl·MgCl2·7H2O was found, and no solid solution was formed. The Pitzer model and its extended Harvie-Møller-Weare (HMW) model were used for predicting the solubilities of the quaternary system (LiCl + MgCl2 + Li2SO4 + MgSO4 + H2O) at 288.15 K, and the predicted results agree well with the experimental values.

Phase Equilibria for the Aqueous Quinary System Li+, Na+, K+, Mg2+//Cl––H2O Saturated with NaCl·2H2O at 258.15 K

“…The studies on system Li + , Na + , K + /Br – –H 2 O and Li + , Na + , K + //Br – , SO 4 2– –H 2 O at 298.15 K were carried out by Cui et al and Guo et al Furthermore, Sang et al studied the stable phase equilibria of quaternary system LiBr–NaBr–SrBr 2 –H 2 O at 308.15 and 323.15 K, and the results show that the solubility of LiBr·2H 2 O is the highest in both temperatures. Wang et al and Li et al investigated the experimental and thermodynamic modeling of the Li 2 SO 4 + Na 2 SO 4 + MgSO 4 + H 2 O and LiCl + MgCl 2 + Li 2 SO 4 + MgSO 4 + H 2 O systems at 288.15 K, respectively. Zeng et al studied the solubilities and physicochemical properties of the aqueous quaternary system Li + , K + , Rb + //borate–H 2 O at 348 K. Most of the current research work focused on normal and high temperatures.…”