Application of thermal analysis methods in the study of sintered uranium dioxide preparation. I

Thermal analysis was used in the study of drying ammonium polyuranate gel prepared by internal gelation of uranyl nitrate solutions with urea and urotropine. The analysis of the differential curves of weight changes with linear temperature increase showed that temperatures above 180 degC should be used for drying to prepare a high-quality product which can easily be further heat treated. For the first water fractions released at temperatures up to 140 degC an activation energy of 49.6 kJ/mol was found which only slightly exceeds the evaporation heat of water. (Ha)