The conversion of UO 2 via ammonium uranyl carbonate: Study of precipitation, chemical variation and powder properties
Abstract
Ammonium uranyl carbonate (AUC) compounds, prepared in laboratory by adding different types of solutions containing ammonium carbonate to uranyl nitrate (UNH) solution of natural uranium, are identified by chemical analysis, DTA/TGA analysis, and by single crystal X-ray diffraction. The chemical composition of AUC precipitates varies according to the C/U ratio of the precipitation solution. A C/U ratio ⩾ 7.5 is found to be critical for the synthesis of AUC with a constant composition represented by the formula (NH 4) 4[UO 2(CO 3) 3]. The powder properties are determined and correlated with the precipitation conditions. The mean particle size increases with decreasing U concentration of UNH solution and with higher precipitation temperatures. The UO 2 conversion via AUC is characterized by the formation of discrete particles of 40-300 μm in size with a specific surface area of 7.5-10.5 m 2/g which permits direct pelletizing and, at the same time, assures good sinterability.
- Publication:
-
Journal of Nuclear Materials
- Pub Date:
- September 1981
- DOI:
- 10.1016/0022-3115(81)90182-3
- Bibcode:
- 1981JNuM...99..135Y