Precipitation of thorium or uranium(VI) complex ion with cobalt(III) or chromium(III) complex cation, (2)

The precipitations of thorium and uranium(VI) sulfito complex ions with hexammine cobalt(III) chloride as the precipitant have been studied. The orange-colored uranium(VI) precipitate obtained is [Co(NH3)6]4[UO2(SO3)3]322H2O, which is in the form of square bipyramid, about 4 μm across in a cubic symmetry of the diamond type with a=10.40 A. It decomposes to an oxide mixture of Co3O4 and U3O8 about 8500C in the air through a sulfate mixture of CoSO4 and UO2SO4. Composition of the thorium precipitate varies with the precipitation conditions. Therefore, it is considered that the thorium precipitate contains thorium hydroxide and basic thorium sulfite. (auth.)