Separation of U4+/UO22+from the chloride molten salts with microplasma gaseous anodes

The efficient extraction and recovery of uranium from spent fuel is crucial for the sustainable development of nuclear energy. Pyrochemical reprocessing based on chloride molten salt electrolysis shows promise in addressing this challenge but still has several key issues remain unresolved. The non-contact microplasma gas electrode may be an ideal anode in this system, which can solve the problem of anode corrosion. Herein, we propose combining microplasma anodes with molten salt electrochemistry to explore the feasibility of separating U4+ and UO22+ from chloride molten salts and to investigate the effects of electrochemical parameters on the separation of U4+ and UO22+. Experimental results demonstrate that microplasma anodes exhibit excellent performance in separating U4+ and UO22+ from molten salts to form Al-U intermetallic and UO2 solids, respectively. The composition of the products and the deposition rate of the uranium were significantly influenced by electrolysis temperature and current, whereas the initial concentration of reactants had a minimal overall impact on the experiments. Under conditions of prolonged electrolysis, the microplasma anode achieves high separation efficiencies for both U4+ and UO22+ (>96 %).