Experimental determination of the isotherm at 15°C of the system Mg2+/Cl-, SO42--H2O

The diagram of the ternary system Mg2+/Cl-, SO42- -H2O was established at 15degreesC by means of analytical and conductimetric measurements. Three compounds were found in this diagram, which are MgSO(4)(.)6H(2)O, MgSO(4)(.)7H(2)O, and MgCl(2)(.)6H(2)O. The solubility field of MgSO(4)(.)7H(2)O is important whereas those Of MgSO(4)(.)6H(2)O and MgCl(2)(.)6H(2)O are small., The composition's (mass-%) of the two invariant points determined by the two methods are: MgSO4:MgCl2 = 2.73:33.80 and MgSO4: MgCl2 = 3.38:28.91. Both the measured and the calculated isotherm at, 15degreesC have been used for modelling of the diagram Mg2+/Cl-, SO42- -H2O between 0 and 35degreesC. The polythermal invariant point was approximately located between 15 and 10degreesC.