Thermodynamic study of uranium oxalate precipitation solubility and supersaturation ratio determination

M. Bertrand (1) , A. Guitierrez-Chavida (1) , E. Plasari (2) , H. Muhr (2) , N. Vigier (3)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
2 LRGP - Laboratoire Réactions et Génie des Procédés
3 AREVA

Oxalic precipitation is usually applied to process radioactive wastes or to recover actinides from a multicomponent solution. The driving force of precipitation reactions is given by supersaturation, which characterizes the deviation from the equilibrium state. Precipitation mechanisms, such as nucleation, crystal growth or agglomeration, are governed by supersaturation, which is therefore a crucial parameter to determine for process control. This work focuses on the description of a thermodynamic study of uranium (IV) oxalate precipitation in order, on the one hand, to develop a solubility model and, on the other hand, to estimate supersaturation ratio.

Mots clés: thermodynamics; solubility; supersaturation; uranium

Domaines: Physique Nucléaire Expérimentale [nucl-ex]; Physique Nucléaire Théorique [nucl-th]

M. Bertrand, A. Guitierrez-Chavida, E. Plasari, H. Muhr, N. Vigier. Thermodynamic study of uranium oxalate precipitation solubility and supersaturation ratio determination. EUROPEAN SYMPOSIUM ON APPLIED THERMODYNAMICS, Jun 2018, Prague, Czech Republic. ⟨cea-02339304⟩