Carbamoylalkylphosphonates for Dramatic Enhancement of Uranium Extraction from Phosphates Ores

We describe here the full synthesis of a novel family of bifunctional ligands and present a complete study of their extraction properties in regards to an aqueous phosphoric acid solution containing uranium. We developed a high yielding synthesis of amido phosphonate ligands and focused our investigation on the effect of steric hindrance on the methylene bridge between the two functions. These new bifunctional ligands were found to extract selectively hexavalent uranium U(VI) with high distribution coefficient (D) and selectivity towards iron Fe (III) in 5 M phosphoric acid solution. From a structure-activity approach a specific ligand called DEHCNPB has been put forward in regard to the outstanding results obtained for the selective extraction, and quantitative recovery of uranium compared to the URPHOS reference system.