Dissolution of uranium dioxide powder in carbonate-peroxide solution

The effects of different dissolution parameters (solid-liquid ratio, peroxide concentration, carbonate concentration, countercation and pH) on the dissolution behavior of UO₂ powder in carbonate-peroxide solution were investigated. The results indicate that increasing H₂O₂ concentration evidently enhances the dissolution of UO₂, while increasing carbonate concentration has no apparent influence on the dissolution rate. (NH₄)₂CO₃ presents a noticeable behavior over the performance of Na₂CO₃ at the same initial pH. Additionally, the dissolution behavior of UO₂ is significantly affected by pH value, since the equilibrium concentration of uranium reached lowest in Na₂CO₃ solution at around initial pH 9.4. (author)