Kinetics of thermal decomposition of Th(C2O4)2·6H2O

Thermal decomposition of thorium oxalate hexahydrate was investigated under nonisothermal and isothermal conditions in moist argon by using simultaneous thermogravimetric–differential thermal analyser. Nonisothermal experiments were carried out at various linear heating rates. Intermediates formed in each stage of the thermal decomposition of thorium oxalate hexahydrate were deduced. Kinetics of decomposition in each stage were evaluated from the dynamic TGA–DTA data by means of Coats and Redfern equation. The values of the activation energy (E) and the pre-exponential factor (A) of each stage of the thermal decomposition at various linear heating rates were calculated. These kinetic parameters were evaluated from isothermal experiments also and probable decomposition mechanism is proposed.