Synthesis and Morphological Control of UO2F2 Particulates

Uranium-based microspheres are of interest due to their potential applications as targets for medical isotopes production, as fuel for nuclear reactors, and as standardized materials for nuclear forensics. Here, for the first time, UO2F2 microspheres (1–2 μm) have been prepared from the reaction between UO3 microspheres and AgHF2 in an autoclave. In this preparation, a new fluorination method has been applied, and HF(g)produced in situ from the thermal decomposition of AgHF2 and NH4HF2was used as the fluorinating agent. The microspheres were characterized by powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Diffraction results indicated that the reaction performed with AgHF2 at 200 °C led to anhydrous UO2F2 microspheres, while at 150 °C, hydrated UO2F2 microspheres were obtained. Meanwhile, NH4HF2 led to the formation of contaminated products as driven by the formation of volatile species.