A two-cycle countercurrent extraction process for recovery of highly pure
uranium from fertilizer grade weak phosphoric acid. The proposed process
uses selective extraction using di-(2-ethyl hexyl) phosphoric acid
(D2EHPA) and tri-n-butyl phosphate (TBP) with refined kerosene as
synergistic extractant system on hydrogen peroxide treated phosphoric
acid, and stripping the loaded extract with strong phosphoric acid
containing metallic iron to lower redox potential. The loaded-stripped
acid is diluted with water back to weak phosphoric acid state and its
redox potential raised by adding hydrogen peroxide and re-extracted with
same extractant system. This extract is first scrubbed with sulfuric acid
and then stripped with alkali carbonate separating iron as a precipitate,
treated with sodium hydroxide precipitating sodium uranate, which is
re-dissolved in sulfuric acid and converted with hydrogen peroxide to
highly pure yellow cake of uranium peroxide.