Kinetics of thermal decomposition of Th(C2O4)(2)center dot 6H(2)O

Thermal decomposition of thorium oxalate hexahydrate was investigated under nonisothermal and isothermal conditions in moist argon by using simultaneo us thermogravimetric-differential thermal analyser. Nonisothermal experimen ts were carried out at various linear heating rates. Intermediates formed i n each stage of the thermal decomposition of thorium oxalate hexahydrate we re 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 calculat ed. These kinetic parameters were evaluated from isothermal experiments als o and probable decomposition mechanism is proposed. (C) 2000 Elsevier Scien ce B.V. All rights reserved.