Heterophase interaction of uranium dioxide with chromium(III) and aluminum(III) in equimolar NaCl-KCl melt

Heterophase reactions of uranium dioxide with Cr(III) and Al(III) in molten NaCl-KCl mixture at 1023 K were studied. Chromium(III) was found to be almost inactive with respect to uranium dioxide. In the case of aluminum(III) the reaction equilibrium is gradually shifted to the right. The reaction products are uranium(IV) and aluminum oxide, which during electrocrystallization of uranium dioxide is localized at the faces of growing crystals or in the intercrystalline cavities. Apparent equilibrium reaction constant K*(2) determined from the experimental data agrees well with the results of thermodynamic calculations.