Sorption of Uranium and Rare-Earth Elements to Remove Radioactive Impurities in the Processing of Phosphate-containing Raw Materials

• Published in: Radiochemistry (New York, N.Y.) N.Y.), 2021-08, Vol.63 (4), p.477-483
• Main Authors: Elatontsev, D. A., Mukhachev, A. P., Korovin, Yu. F., Voloshin, N. D.
• Format: Article
• Language: English
• Subjects: Acid leaching; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Fluorine; Nuclear Chemistry; Oxidation; Phosphorus; Radioisotopes; Rare earth elements; Raw materials; Separation; Sodium nitrite; Sorbents; Sorption; Uranium; Uranium oxides
• ISSN: 1066-3622; 1608-3288
• DOI: 10.1134/S1066362221040111

The process of sorption separation of uranium and REE after acid leaching of uranium-phosphorus-rare-earth chemical concentrate onto a modified granular sorbent based on cellulose phosphate (MGCP) was studied. It was found that MGCP efficiently absorbs U(VI) from solution, while REEs remain together with phosphorus and fluorine in the raffinate. The dependences of the exchange capacity of MGCP for U(VI) and REE on the volume of the passed filtrate were determined. The dynamic capacity of the sorbent for U(VI) reaches 100 mg/g, and the degree of extraction of U(VI) from the solution exceeds 94%. It has been shown that it is expedient to desorb uranium with a (NH 4 ) 2 CO 3 solution at a temperature of 50 ± 2°C, providing preliminary oxidation of U(IV) to U(VI) directly on the sorbent with a 0.5% HNO 3 solution containing 2% NaNO 2 . With sorption of U(VI) on MGCP, the stage of extraction purification from REE in the production of triuranium octoxide may be excluded. The possibility of sorption separation of REE from radioactive isotopes on MGCP was determined. The sorbent capacity for REE is 70 mg/g.