Fabrication of CeO2 ceramic spheres as a surrogate of nuclear fuel by an improved microwave-assisted rapid internal gelation process

Fabrication of Nd- and Ce-doped uranium dioxide microspheres via internal gelation

“…Suresh Kumar et al [5] tested the IG process for the production of bulk Ce-doped ammonium diuranate (ADU) gels, using Ce III as dopant precursor. Moreover, IG studies to prepare CeO 2 particles are available in literature, they use Ce IV solution, pre-neutralised with NH 3 solution, as metal precursor [6][7][8][9]. Katalenich [10] compared the usage of Ce III and Ce IV as metal precursors and came to the conclusion that strong Ce gels with a quick gelation time could be achieved using diammonium cerium(IV) nitrate, whereas a Ce III nitrate feed solution did not lead to satisfying gels.…”

Cation-heterogeneity in internally gelated U1-Ce O2-, 0.15 ≤ z ≤ 0.3 microspheres

“…Investigating and understanding in detail the gelation process is a challenging task as it can be influenced by multiple factors happening at very small scales such as the mixing of reactants, the droplet formation, the displacement and likely start of surface interaction upon contact with the Si-oil, and finally by the heat propagation from the hot gelation medium into the broth droplet triggering HMTA and Urea protonation/decomposition [37]. This leads to a release of ammonia causing the subsequent precipitation of UO 2+ and Ce 3+ /Ce 4+ species [39], [40]. For each species, precipitation may progress on separate paths with different reported pH ranges [39] and kinetics while resulting in different products [39], [41].…”