Thermodynamic analysis and experimental study on the reduction of mixed oxides including uranium oxide by lithium

In order to determine the operating conditions of an uranium reduction process with U₃O₈-Li-LiCl system, the operating conditions have been evaluated in thermodynamic aspects and the results were experimentally confirmed in this study. All the reduction experiments were conducted in an argon atmospheric glove box, and the resultant degree of reduction was determined by analyzing the product using XRD and TGA. In the results of this study, a reduction yield greater than 95% is achieved within about 3 hours of reaction. The effects of the added quantity of Li and LiCl to the reduction yield of U₃O₈ and the preferential removal of several metal oxides accompanying U₃O₈ in the course of reduction were discussed. For a greater reduction of U₃O₈, an additional 20% of Li is required when compared to the stoichiometric composition. The proper composition of LiCl is about 75% based on the weight of U₃O₈ charged.