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

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

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.