EXTRACTION OF URANIUM (VI) FROM NITRIC ACID AND NITRATE SOLUTIONS BY TRIBUTYLPHOSPHATE/KEROSENE

Abstract

The extraction of nitric acid and hexavalent uranium from nitric acid and nitric acid containing uranium (VI) media by tributyl phosphate (TBP)/kerosene has been studied, and all factors affecting the extraction process (time of mixing, uranium concentration, nitric acid concentration, TBP concentration, temperature) have been investigated. The equilibrium constant of the extraction reaction of uranium by TBP: UO₂^{2 +} + 2 NO₃^- + 2 TBP \leftrightarrows UO₂(NO₃)₂ . 2TBP was found to be 10^2.464, 10^2.668 L⁴/mol⁴ at 25 \ ^oC, and the enthalpy was -16.47, -23.07 kJ/mol for 0.5 M and 1 M nitric acid concentrations, respectively. The purification of the yellow cake produced at the pilot plant of uranium extraction from the Syrian wet phosphoric acid was investigated using TBP/kerosene.