Uranyl Selenate, UO₂SeO₄

Uranyl Selenate, UO₂SeO₄.xH₂O, is present in the glassy mass obtained by evaporating a solution of uranyl hydroxide in selenic acid. It has not been obtained in a pure state. Such solutions also yield acid salts, of which the following have been isolated:

UO₂SeO₄.H₂SeO₄.18H₂O,
2UO₂SeO₄.H₂SeO₄.12H₂O.

Double selenates, of composition R^•₂SeO₄.UO₂SeO₄.2H₂O (R^• = K, NH₄), have been obtained in crusts of yellow crystals by evaporation of solutions of the alkali uranate in selenic acid.