METHOD FOR OBTAINING OF HIGH-CLEAN CERIUM (III) NITRATE SOLUTION Russian patent published in 2018 - IPC C01F17/00 C01G1/08 

FIELD: chemistry.

SUBSTANCE: to implement the method, high-purity cerium dioxide is treated at 70-80^oC with concentrated nitric acid containing 1.5-5 wt % of hydrofluoric acid from the stoichiometric, subsequent addition of hydrogen peroxide in a 1.5-5-fold excess from the stoichiometric amount, reaction mass heating to 90-100°C at stirring, cooling and filtering of the resulting solution. The filtrate containing cerium nitrate is then heated to 50-60°C, oxalic acid is added in an excess of 10-20% relative to the stoichiometric amount. The precipitated cerium oxalate is subjected to heat treatment in air at 320-370°C. The heat treatment product is dissolved at 80-90°C in a concentrated nitric acid, used in an excess of 5-20% of the stoichiometric amount, and with addition of hydrogen peroxide taken in a 1.5-5-fold excess from the stoichiometric amount with respect to cerium dioxide to form the final product, an aqueous solution of cerium nitrate (III).

EFFECT: obtaining of a high-purity product that meets the requirements of modern technology.

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