LIQUID-LIQUID EXTRACTION OF METAL IONS BY NEUTRAL PHOSPHOR- AMIDES. PART I, EXTRACTION OF URANYL IONS FROM NITRATE AND SULPHATE MEDIA. EXAMINATION OF EXTRACTED SPECIES BY UV/V1S AND sip NMR SPECTROSCOPY.

Abstract

ABSTRACT The extraction of uranyl nitrate and uranyl sulphate from aqueous media by the neutral chelating diphosphoramides CH3-N[P(OKNMe2)2] (NIPA) and its less hydrophilic homologues R-N[P(O)(NMe2)2]2 (R = -C12H25 (OD1PA) or -C16H33 (OHDIPA)), diluted in CH3NO2 or toluene, has been studied. In the presei ce of HNO3, NaNO3, NaCl, and Na2SO4 as salting-out agents, extraction is generally excellent. Some of the extracted complex species have been identified by comparing their 31P NMR and UV/vis spectra with those of pure complexes of known structure. The results are compared with extractions using tri-n-butyl phosphate (TBP) as complexing agent.