Thermal and X-ray studies on double sulphates of uranium(IV) with magnesium, nickel, copper and zinc

Abstract

Double sulphates of uranium(IV) with Mg, Ni, Cu and Zn with the general formula MU(SO4)3·8H2O were prepared from their respective metal sulphates. All the four compounds are isostructural and belong to monoclinic system. The thermal decomposition at 850 °C results in a single phase of triuranates MU3O10 which on further heating above 980 °C decompose to give the metal oxide and U3O8 in case of Ni and Zn compounds and MUO4 for Mg and Cu compounds. The activation energy for dehydration of these four compounds has been calculated using non-isothermal thermogravimetric data.