Preparation of unsupported granulated triuranium octoxide and its use as catalyst of conversion of ammonium nitrate to nitrogen in an NH 4 NO 3 –H 2 O vapor–gas mixture

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.