The extraction equilibria were investigated of the thenoyltrifluoroacetone (TTA) chelate of uranyl ion between aqueous perchlorate
medium and thirteen organic solvents. The extracted species was shown to be UO2A2. The solubility parameter of the chelate was estimated from the partition data and it was confirmed that the relationship
lgPM=n lgPHA+const. holds for the present system. When the extraction constant (Kex) is considered in relation to the distribution coefficients, theKex values are expected to be constant under certain conditions for all of the solvents; the lgKex values were found to be constant (lgKex=−2.85±0.17).