Dissolution kinetics and thermodynamics of uranium from a boltwoodite ore for nuclear fuel cycle application

Abstract

The demand for pure uranium and uranium compounds of an industrial standard is tremendously increasing due to its wide array of utilities in electron microscopy, catalysis, armor-piercing, and nuclear explosions, among others. The raw ore and some of the products after alkaline leaching were characterized by X-ray fluorescence, X-ray diffraction, inductively coupled plasma mass spectroscopy, and scanning electron microscopy analyses. Dissolution kinetics and thermodynamics were examined under the experimental conditions at different sodium hydroxide concentrations, reaction temperature, and particle size towards purified uranyl leach liquor which could further be processed to industrial ammonium diuranate. The experimental results affirmed that the best parameters comprised a residence time of 120 min, reaction temperature of 75 degrees C, sodium hydroxide concentration of 2.5 mol/L, and particle size of 75 mu m, yielding a dissolution efficiency of 96.1% with an activation energy of 41.39 kJ/mol.