“…There have been some experimental studies that relate to the quaternary system K + , Mg 2+ //Cl – , SO 4 2– -H 2 O, as described below: the ternary system K + , Mg 2+ //Cl – -H 2 O at 273.2, , 278.2, 288.2, 298.2, 323.2, 348.2, , and 373.2 K; ternary system K + , Mg 2+ //SO 4 2– -H 2 O at 273.2, 298.2, , 318.2, 323.2, 348.2, 358.2, and 373.2 K; , ternary system K + //Cl – , SO 4 2– -H 2 O at 273.2, 298.2, 323.2, 348.2, and 373.2 K; , ternary system Mg 2+ //Cl – , SO 4 2– -H 2 O at 298.2, 303.2, 323.2, 348.2, and 373.2 K; and quaternary system K + , Mg 2+ //Cl – , SO 4 2– -H 2 O at 273.2, 288.2, 298.2, 308.2, 328.2, 348.2, and 373.2 K . The results showed that magnesium sulfate exists in a variety of hydrate crystalline forms and is prone to form a variety of double salts with potassium salts.…”