Continuous extraction and separation of Am(III) and Cm(III) using a highly practical diamide amine extractant

高実用性の新規抽出剤によるAm(III)とCm(III)の連続抽出分離

鈴木 英哉; 津幡 靖宏   ; 黒澤 達也*; 佐川 浩*; 松村 達郎  

Suzuki, Hideya; Tsubata, Yasuhiro; Kurosawa, Tatsuya*; Sagawa, Hiroshi*; Matsumura, Tatsuro

Am(III)とCm(III)との相互分離のための新規抽出剤として、5本の2-エチルヘキシル基を持つADAAM(EH)を開発した。ADAAM(EH)は、Nドナーのソフト性とOドナーのハード性を併せ持った多座配位子で、高硝酸濃度条件下において、Am(III)とCm(III)の分離係数5.5が得られた。さらに、ADAAM(EH)は高い実用性を有しており、ADAAM(EH)を用いて多段向流式ミキサセトラによる連続抽出試験を実施し、非常に良好なAm(III)とCm(III)の分離結果が得られた。

A highly practical diamide-type extractant, which is an alkyl diamide amine with 2-ethylhexyl alkyl chains (ADAAM(EH)), was investigated for mutual separation of Am(III) and Cm(III). ADAAM(EH) is a multidentate ligand with one soft N-donor atom and two hard O-donor atoms in its central frame. This tridentate arrangement of donor atoms provides selective binding to Am(III) compared to that with Cm(III) in highly acidic media, resulting in separation factors of up to 5.5. A continuous liquid-liquid extraction and stripping test was conducted using a multistage countercurrent mixer-settler extractor with ADAAM(EH) in n-dodecane. In this test, separation of Am(III) and Cm(III) was achieved with very high yield.