Solvent extraction of various metals including actinides by bidentate and tridentate diamides

Sasaki, Yuji  ; Kimura, Takaumi ; Oguma, Koichi*

Many diamide-type extractants were synthesized and tested for the extraction of actinides (III), (IV), (V) and (VI). The diglycolamides (DGA) with two amidic oxygen and one ether oxygen, which show the tridentate feature, have the high extractability of actinides (An). In order to increase the lipophilic property, the diglycolamides with the different functional groups attached to N atoms were synthesized and examined for their extractability. It was found that tetraoctyl-diglycolamide (TODGA) and tetradecyl-diglycolamide (TDDGA) exhibit the satisfactory dissolution into dodecane with less solubility in HO. The results of various metal extractions using TODGA revealed that the divalent, trivalent and tetravalent metals with ionic radius of 90-120 pm gave notably high D values. After elucidation of the effect on substitution of the functional group, the chemical form of DGA to have high performance on An extraction was proposed.