Thermal decomposition of oxalates. Part 13.—Surface area changes in the thermal decomposition of uranyl oxalate

Abstract

The thermal decomposition of uranyl oxalate trihydrate has been studied and the surface area changes associated with the isothermal decomposition of the anhydrous salt in air have been determined. The maximum in surface area recorded in the isothermal decomposition coincides with an inflexion in the weight loss data which is not due to the formation of an intermediate compound. The nitrogen adsorption isotherms indicate that the probable cause of this inflexion is the development and eventual collapse of a porous structure in the solid, leading to an acceleration of the oxide formation.