Preparation of unsupported granulated triuranium octoxide and its use as catalyst of conversion of ammonium nitrate to nitrogen in an NH4NO3–H2O vapor–gas mixture

Resumo

Formulation of the forming paste for preparing unsupported granulated triuranium octoxide U₃O₈ was developed. The mixture contains U₃O₈ and (NH₄)₂U₂O₇ in a weight ratio from 1: 1 to 1: 1.5, and also water in an amount of 25–40 wt % relative to the sum of the dry components. Calcination of crude granules at 800–1100°С results in formation of strong ceramic granules with 57–45% open porosity, consisting of U₃O₈. Granulated U₃O₈ efficiently catalyzes the conversion of ammonium nitrate to nitrogen in an NH₄NO₃–H₂O vapor–gas mixture with the addition of ammonium carbonate. The absence of support makes the catalyst composition more definite and simplifies its regeneration.