From Nd(III) and Pu(III) Oxalates to Oxides: Influence of Nitrilotris(methylenephosphonic acid) on Chemical Composition, Structure, and Morphology

Neodymium oxalate structure and morphology were modified by adding a phosphonate, NTMP, during the oxalic precipitation step. Spherical agglomerates of neodymium oxalate Nd-2(C2O4)(3)(H2O)6 center dot 12H(2)O composed of thin hexagonal rods were precipitated instead of decahydrated oxalate Nd-2(C2O4)(3)(H2O)6 center dot 4H(2)O with rod-like particles usually obtained in the absence of additive. Despite some differences in the complexation with NTMP and complexity from redox, the use of NTMP was successfully transposed to the plutonium system. Spherical agglomerates of plutonium (III) oxalate were so obtained, leading to spherical agglomerates of PuO2 after thermal treatment.