The kinetics of thermal dehydration of calcium copper acetate hexahydrate

Abstract

The kinetics of the thermal dehydration of crushed crystals of CaCu(CH 3CO 2) 4·6H 2O in a flowing nitrogen atmosphere have been studied by means of isothermal gravimetry. At higher temperatures than 85°C the dehydration seemed to be described by three-dimensional phase boundary reactions, R 3(α). At temperatures lower than 80°C, the initial part of the dehydration could be described by phase boundary reactions, R 3(α), that of the middle part follows the Avrami-Erofeev type reaction, A 2.5(α), and then the kinetics of the final part followed diffusion-controlled models. These transitions of the dehydration mechanisms have been discussed on the basis of the diffusion process of dissociated water molecules.