Phase Equilibria of the Reciprocal Quaternary System (Li+, NH4+//Cl−, SO42−-H2O) at 288.15 K

Abstract Based on the isothermal solution equilibrium method, a systematic study of the quaternary (Li+, NH4+//Cl−, SO42−-H2O) and its subsystems ((NH4)2SO4-NH4Cl-H2O, NH4Cl-LiCl-H2O and (NH4)2SO4-Li2SO4-H2O) at 288.15 K were undertaken. The phase diagrams of these systems were drawn by the experimental solubility data. The ternary system (NH4)2SO4-NH4Cl-H2O is a simple system at 288.15 K while solid solution (LiCl•2H2O)x(NH4Cl)1-x was formed in the ternary system NH4Cl-LiCl-H2O. The compound salt LiNH4SO4 and solid solution (Li2SO4•H2O)x(LiNH4SO4)1-x were produced in the system (NH4)2SO4-Li2SO4-H2O. The phase diagram of the quaternary system (Li+, NH4+//Cl−, SO42−-H2O) include seven solid phase crystallization regions (NH4Cl, LiCl•2H2O, (LiCl•2H2O)x(NH4Cl)1-x, Li2SO4•H2O, (NH4)2SO4, LiNH4SO4 and (Li2SO4•H2O)x(LiNH4SO4)1-x).