A wet method was studied to mix magnesium and uranium finely for fabricating homogeneous solid solution MgyU1-yO2+x (x ≥ 0 or x <). The method consists of precipitate formation of ammonium diuranate (ADU) from dilute HNO3 solution containing calculated concentrations of uranyl nitrate, NH4NO3 and Mg(NO3)2 · 6H2O. Since a small portion of the solution containing Mg is held in the cream-like precipitate of ADU, subsequent heating after careful drying of the precipitate leads to form homogeneous solid solutions. NIH4NO3 prevents the solution from precipitating Mg(OH)2 on ammonia addition. The concentration relation of the chemical species was examined for 10 ml of 0.21 M uranyl nitrate solution in 0.014 M HNO3. It was found that Mg(OH)2 did not precipitate with the addition of 2 g NH4NCO3. The 5 ml addition of 25 wt% ammonia water was sufficient for ADU formation. The concentration of Mg in the solid was proportional to the amount of Mg(NO3)2 · 6H2O under the relevant condition. From the vacuum dried ADU precipitate (method (4)), homogeneous MgyU1-yO2+x solid solutions were prepared.
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Materials Science(all)
- Nuclear Energy and Engineering