Crystallization of nitrates in the presence of HNO3 and its relation to physical and chemical properties of the systems

Crystallization of Ammonium Nitrate from Nonaqueous Solvents

“…Given the critical role of the near-ambient temperature IV−III phase change in the deterioration of solid ammonium nitrate upon prolonged storage, a variety of studies aimed at kinetically delaying its onset have been reported. Incorporation of additives, including magnesium nitrate, nitric acid, aluminum(III) salts, , or a variety of proprietary additives, can provide some measure of kinetic stabilization of phase IV. The thermal interconversions of the various phases of ammonium nitrate, particularly phases II, III, and IV, are also well-known to be quite dependent on water content. − It has been shown that the IV−III phase change is kinetically sluggish in anhydrous ammonium nitrate, so that routine thermal analysis frequently displays only the IV−II transition .…”

An Examination of the Influence of Divalent Cationic Dopants on the Bulk and Surface Properties of Ba(NO3)2 Associated with Crystallization

“…The volume reduction of the high level waste stream by evaporation, prior to immobilization though vitrification, results in the precipitation of divalent nitrates, notably Ba(NO 3 ) 2 . In addition, significant amounts of the radiogenic self-heating 90 Sr isotope, are also found and the precipitates overall exhibit a highly dense phase that has a low solubility in water and dilute acids becoming appreciably less soluble with the increasing nitric acid concentration that results from evaporation during reprocessing. In addition, Sr(NO 3 ) 2 has been shown experimentally to coprecipitate with Pb(NO 3 ) 2 forming a mixed cationic structure Pb x Sr 1− x (NO 3 ) 2 .…”