A study of Mangesium Oxysulphates

The reactions which take place in the system MgO-MgSO4-H2O at concentrations of MgSO4 solutions up to saturation and temperatures from 30 to 120 °C have been studied in detail. Four oxysulphates have been found, namely, 5Mg(OH)2.MgSO4. 3 or 2H2O, 3Mg(OH)2.MgSO4.8H2O, Mg(OH)2. MgSO4.5H2O, and Mg(OH)2.2MgSO4.3H2O, and an equilibrium diagram has been prepared which gives the conditions at which each is stable. X-Ray diffraction powder patterns of each of the oxysulphates are given and the stabilities of the compounds are briefly discussed.