Organophosphorous Compounds

Abstract

Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions.In the present study, the extraction of nitrates of uranium and thorium in their solid form was carried out using supercritical carbon dioxide (Sc-CO 2 ) modified with various organophosphorous compounds such as dialkylalkyl phosphonates, trialkyl phosphates and trialkyl phosphine oxides in the presence of co-solvents such as methanol, dichlormethane and n-hexane. The influence of ligand and co-solvent on the extraction of the metal nitrates was studied in detail. These studies have established that co-solvent plays an important role in the extraction as well as fractionation of uranium and thorium nitrates. Polar co-solvent, methanol provided faster extraction without fractionation whereas the non-polar solvent, e.g. n-hexane provided some fractionation of metal nitrates though the extraction kinetics was slower.