INTERACTION OF Pu(VI) AND Np(VI) WITH CARBOHYDRAZIDE IN NITRIC ACID SOLUTIONS

Abstract

Abstract. The kinetics of Pu(VI) and Np(VI) recovery by carbohydrazide in an aqueous nitric acid solution was researched spectrophotometrically. Regarding to Pu(VI) it was established that in the interval of [HNO3] = 0.75-3.0 M and [CO(N2H3)2] = 0.1-0.4 M, the reaction rate was proportional to the concentration of Pu(VI). The reaction order with respect to carbohydrazide was determined to be 2.3, and -3 to nitric acid. The found activation energy of the reaction was 111 kJ·mol −1 . Regarding Np(VI), it was found that in the interval of [HNO3] = 0.75-3.0 M and [CO(N2H3)2] = 0.03-0.12 M, the reaction rate was proportional to the Np(VI) concentration. Reaction order with respect to carbohydrazide was determined to be 1.15, and -1.35 with respect to nitric acid. The found activation energy of the reaction was 85 kJ·mol −1 . Based on this kinetic data, a possible fundamental reaction mechanism was theorized.