Studies of dehydration kinetics of Li2SO4·H2O by the master plots method

The kinetics of Li₂SO₄·H₂O dehydration in static air atmosphere was studied on the basis of nonisothermal measurements by differential scanning calorimetry. Dehydration data were subjected to an integral composite procedure, which includes an isoconversional method, a master plots method and a model-fitting method. Avrami-Erofeev equation was found to describe all the experimental data in the range of conversion degrees from 0.1 to 0.9. The determined activation energy equals 65.45 kJ·mol⁻¹ with standard deviation ±0.47 kJ·mol⁻¹. The estimated value of parameter m in Avrami-Erofeev equation is 2.15 with standard deviation ±0.11. Also, the obtained pre-exponential factor is 7.79×10⁵ s⁻¹ with standard deviation ±0.55×10⁵ s⁻¹. The results show that the present integral composite procedure gives self-consistent kinetic parameters.