Kv. Rajagopalan et al., THERMAL-DECOMPOSITION OF URANYL-NITRATE HEXAHYDRATE - A THERMAL-ANALYSIS - MASS-SPECTROMETRY STUDY, Journal of thermal analysis, 44(1), 1995, pp. 89-96
TG-DTA-EGA studies have shown that anhydrous uranyl nitrate cannot be
obtained by thermal decomposition of uranyl nitrate hexahydrate. Hydro
lysis and polymerization of the salt during dehydration resulted in hy
droxynitrates which decomposed in multiple steps with the evolution of
oxides of nitrogen and water. The extent of hydrolysis depended on th
e sample size, heating rate and nature of sample containment. Large sa
mples on decomposition at relatively high heating rates showed evoluti
on of nitric oxide even above 500-degrees-C. Infrared studies on the r
esidues prepared at various temperatures supported the conclusions.