| Accurate solubility data of calcium chloride in pure water have found important applications in the field of lithium extraction from salt lake, food industry and material design. However, the experimental data reported by different authors don't agree with each other in the past over 100 years. The widely used data evaluation method, like taking average values of all experimental data, is hard to give convincing results. In this case, a new evaluation method has been suggested in this work, and a reliable set of solubility data of the system CaCl2+H2O was recommended. The principle of the new evaluation method is described as below: (1) The experimental water activities of the unsaturated salt-water system are critically evaluated. Reliable data are selected for the model parameterization in the later. (2) By extensive comparison, the BET model, which has fewer parameters and excellent extrapolation ability, is selected to fit the reliable water activities. (3) Experimental vapor pressure data of the CaCl2-saturated solution are critically evaluated and accurate data are sected as criteria for the later solubility prediction. (4) Solubility of the CaCl2+H2O system is predicted with the BET model applying the selected vapor pressures above saturated solution as criteria, as well as the prediction accuracy. (5) The solubility data from various sources are evaluated with the predicted solubility. After accurate solubility of CaCl2 in water was obtained, the thermodynamic properties of different crystals CaCl2.nH2O (n=2,4,6) was modified.
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