Precipitation of Thorium or Uranium(VI) Complex Ion with Cobalt(III) or Chromium(III) Complex Cation, (II)

Precipitation of Thorium and Uranium(VI) Sulfito Complex Ions

Abstract

The precipitations of thorium and uranium(VI) sulfito complex ions with hexammine cobalt(X) 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 Å It decomposes to an oxide mixture of Co₃0₄ and U₃O₈ above 850°C 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.