METHOD FOR PROCESSING NATURAL URANIUM OXIDES Russian patent published in 2008 - IPC C01G43/01 

FIELD: chemistry.

SUBSTANCE: method implies uranium hot leaching with strong nitric acid and separation of aqueous phase from non-soluble residue prior to extraction processing. Leaching is carried out, weight ratio of nitric acid to uranium being (0.75-0.84): 1, at 85-100°С, which results in aqueous phase uranium concentration of 700-800 g/l. Hot pulp is diluted with dilute nitric acid solutions to uranium concentration of 350-500 g/l in pulp aqueous phase and nitric acid concentration of ca. 1.0 mol/l, which is suitable for extraction processing aqueous phase. Then aqueous phase is separated from the solid residue.

EFFECT: resulting nitric-acid uranium solutions can be easily separated from solid phase and are suspension-free; solutions are suitable for extraction processing.

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