Stable Phase Equilibria in Li ⁺ //Cl ^– , S ${\text{O}}_{4}^{{2 - }}$ , B ₄ ${\text{O}}_{7}^{{2 - }}$ –H ₂ O and Li ⁺ , Mg ²⁺ //Cl ^– , B ₄ ${\text{O}}_{7}^{{2 - }}$ –H ₂ O Quaternary Systems at 273 K

Abstract

The isothermal dissolution method was used to study the stable phase equilibria in the simple quaternary system Li⁺//Cl^–, S${\text{O}}_{4}^{{2 - }}$, B₄${\text{O}}_{7}^{{2 - }}$–H₂O and reciprocal quaternary system Li⁺, Mg²⁺//Cl^–, B₄${\text{O}}_{7}^{{2 - }}$–H₂O at 273 K. The stable phase equilibrium of simple quaternary system Li⁺//Cl^–, S${\text{O}}_{4}^{{2 - }}$, B₄${\text{O}}_{7}^{{2 - }}$–H₂O belongs to hydrate type I, and there is no complex salt. The phase diagram is constituted of an invariant point, three univariant solubility curves, and three solid phase crystalline regions. The stable phase equilibrium of reciprocal quaternary system Li⁺, Mg²⁺//Cl^–, B₄${\text{O}}_{7}^{{2 - }}$–H₂O belongs to complex type, and the double salt of lithium carnallite (LiCl·MgCl₂·7H₂O) is found. There are three invariant points, seven univariant solubility curves, and five solid phase crystalline regions.