Liquid-liquid extraction and recovery of Cerium(IV) and Phosphorus from sulfuric acid solution using Cyanex 923

The work addresses the extraction and separation of cerium(IV) (Ce(IV)) and phosphorus (P) from a H2SO4 solution using Cyanex 923 diluted in n-heptane. The effects of H2SO4 concentration, extractant concentration and P concentration on the extraction have been investigated. The thermodynamic parameters have been determined, showing that the extraction is exothermic. The saturation load capacity and stripping efficiency are discussed in the report. The results of FTIR and NMR show that Ce(IV) and P can form complex in the sulfuric acid media and then are extracted into organic phase by the interaction of Ce(IV) in complex with PO of Cyanex 923. The extraction process was studied. CePO4 powder was prepared by reductive stripping of the loaded organic phase with H2O2. The powder was characterized by XRD and DSL. Because of the high saturation load capacity and stripping efficiency, Cyanex 923 was validated to be a promising extractant for Ce(IV) and P from the H2SO4 solution, providing a potential application for the recovery of Ce(IV) and P from Bayan Obo mixed RE ores.