希土類元素抽出における簡便かつ高機能性抽出剤DODGAAの開発

Development of simple and highly-functional extractant DODGAA on rare earth elements extraction

下条 晃司郎   ; 久保田 富生子*; 後藤 雅宏*; 長縄 弘親  

Shimojo, Kojiro; Kubota, Fukiko*; Goto, Masahiro*; Naganawa, Hirochika

本研究では炭素,水素,酸素,窒素のみからなるジグリコールアミド型抽出剤DODGAAを開発し、ランタノイドの抽出分離挙動について検討した。その結果、DODGAAは同じカルボン酸系工業用抽出剤であるVersatic 10に比べて非常に高い抽出能を示し、リン酸系工業用抽出剤であるD2EHPAやPC-88Aと同等の抽出能を有することを明らかにした。さらに、DODGAAは重ランタノイドに対して高い選択性を有し、軽ランタニド間において高い相互分離能を示した。

In this study, the novel extractant N, N-dioctyldiglycol amic acid (DODGAA) has been developed as a CHON-type extractant, which is composed of only C, H, O, and N atoms. The extraction and separation of lanthanides using DODGAA was compared with that using a carboxylic acid-type extractant (Versatic 10) or organophosphorus extractants (D2EHPA and PC-88A). Of carboxylic acid-type extractants, DODGAA provides an unprecedentedly high extraction performance for lanthanides, which is comparable to that of organophosphorus extractants. Furthermore, it was found that DODGAA shows the greatly high selectivity for heavier lanthanides and the high separation ability between adjacent light lanthanides. It is assumed that the high extraction and separation performances of DODGAA are attributed to involvement of the carboxy group as well as the glycol amic acid site in complexation with lanthanides.