Kinetics of iron(III) chloride extraction with n-tributyl phosphate

The equilibrium and rate of solvent extraction of FeCl₃ complexes from HCl solutions into benzene solutions of tributyl phosphate (TBP) has been studied. The extracted species was found to be FeCl₃·3TBP. The results show that the extraction is first order in both Fe(III) and TBP. The rate constant of adduct formation equals ～1.24M min^?1. The reaction order is zero for the aqueous phase acidity. The rate-controlling steps are discussed in the light of the results.