Deprotonation of an alkylphenyl acid phosphate extractant

摘要

Uranium in wet-process phosphoric acid in the tetravalent state is extracted with an alkylphenyl acid phosphate extractant. The uranium in the pregnant extractant is then oxidized to the hexavalent state and stripped with a phosphoric acid stripping solution. Hydrolysis of the extractant is decreased by decreasing the proton concentration of the extractant which results from acidic impurities, e.g., sulfuric acid and fluorosilicic acid, originally present in the wet-process phosphoric acid. The proton concentration of the extractant is reduced indirectly by treating the phosphoric acid strip solution (1) with reagents which react with the acidic impurities to form water and an insoluble precipitate which is removed from the stripping solution; (2) with reagents to neutralize the acidic impurities in the stripping solution; or (3) by passing the stripping solution through a suitable ion exchange column.