Hydrolysis of Uranyl‐, Nd‐, Ce‐Ions and their Mixtures by Thermal Decomposition of Urea

The hydrolysis of uranyl-, Nd- and Ce-cations, induced by thermal decomposition urea was investigated the impact content experiment temperature on reaction kinetics evaluated. Uranyl precipitated as ammonium diuranate (ADU) with varying stoichiometry. Nd(III) Ce(III) showed comparable pH evolutions lanthanide carbonate hydroxide (LnCO3OH) products were identified, whereas Ce(IV) hydrolysed at lower formed CeO2. precipitation behaviour confirmed for mixtures uranyl lanthanides. Depending content, a partial co-precipitation occurred in U/Nd mixtures. phases also identified precipitates binary U/Ce In ternary U/Nd/Ce compositions, simultaneous observed incorporation lanthanides into ADU phase, presence Ce(IV)/CeO2 led to formation three individual phases.