High-temperature interaction of components of spent uranium nuclear fuel with alkali metal carbonates in the course of voloxidation in the Carbex process

Abstract

Interaction of UO₂, U₃O₈, ZrO₂, Nb₂O₅, CeO₂, Ce₂O₃, Pr₆O₁₁, Eu₂O₃, Yb₂O₃, Tb₇O₁₂, and Re metal with lithium, sodium, and potassium carbonates in the temperature interval 300–900°С was studied using methods of thermal analysis and X-ray diffraction. The major products of the high-temperature reactions are alkali metal uranates and diuranates, and in the case of ZrO₂, Nb₂O₅, and lanthanide oxides, oxides of metals in higher oxidation states and salts of the corresponding metal-containing acids, formed by reactions of the oxides with sodium carbonate.