Determination of Nucleation and Crystal Growth Kinetics in Hostile Environment – Application to the Tetravalent Uranium Oxalate U(C₂O₄)₂^. 6H₂O

Abstract

Abstract A specific apparatus and an original batch method are developed for, respectively, nucleation and crystal growth rate measurements in a hostile environment, such as glove box. Primary nucleation and crystal growth kinetic rates for uranium oxalate are measured over a wide range of temperatures and solution concentrations. The nucleation rate obeys the Volmer‐Weber equation, with activation energies of 182 kJ.mol −1 for the homogeneous nucleation and 102 kJ.mol −1 for the heterogeneous one. The crystal growth rate is first order with respect to the supersaturation and controlled by a surface integration mechanism, characterized by a 29 kJ.mol − 1 activation energy.