KINETICS OF REDUCTION OF URANIUM(VI) TO URANIUM(IV) AT TITANIUM ELECTRODE IN NITRIC-ACID AND HYDRAZINE MEDIA

The kinetic study of the reduction of U(VI) at the titanium electrode in nitric acid and hydrazine media was carried out at 25+/-0.5-degrees -C. Uranium (VI) is reduced through a totally irreversible process and kinetic parameters are affected by both the concentration of nitric a cid and the electrolytic potential. An empirical equation to express t he rate of the reduction of U(VI) was proposed and was confirmed to be in fairly good agreement with the amount of U(IV) produced by the con trolled-potential electrolysis. The optimal condition for the preparat ion of U(IV) from U(VI) was found to be the electrolysis at -0.5V vs. Ag-AgCl/sat. KCl in 1 approximately 2 M HNO3 and 0.1 approximately 0.2 M hydrazine.