Synergistic Extraction of Rare Earth Elements from Phosphoric Acid Medium using a Mixture of Surfactant AOT and DEHCNPB

We describe here the formulation of a new synergistic extractant system for the extraction of rare earth elements from aqueous phosphoric acid solution containing large quantities of impurities currently found in urban mines and secondary deposits. This new synergistic system is original in its concept as it contains the association of the bifunctional extractant amido-phosphonate, known for its high efficiency in the recovery of uranium from phosphate rocks, with the(Bis(2-ethylhexyl) sulfosuccinate sodium) (AOT) surfactant molecule known to form reverse micelles in aliphatic diluents. The mixture was found to extract synergistically rare earth elements with high distribution coefficients (D), and exhibits a high separation factor (S.F.) toward iron (III) from phosphoric acid solution. A complete thermodynamic study of its extraction properties is also presented, showing this system has the ability to extract Rare Earth Elements (REEs) from a wide range of phosphoric acid concentrations, which is often the case in industrial processes.