Mutual separation of actinides from middle lanthanides by the combination of two neutral donors, -tetraoctyl-3,6-dioxaoctanediamide and -tetraetyldiglycolamide

Sasaki, Yuji  ; Morita, Yasuji  ; Kitatsuji, Yoshihiro  ; Kimura, Takaumi 

The separation of Am and Cm from Sm, Eu and Gd was examined by using the combination of new extractant, DOODA (tetraoctyl-3,6-dioxaoctanediamide) and the masking agent, TEDGA (tetraethyl-diglycolamide). These reagents show the neutral donor feature and work in the acidic condition. DOODA can extract light lanthanides with high values into the organic phase, on the other hand TEDGA shows strong complexing ability with middle and heavy lanthanides in the aqueous phase. Americium and Cm behave as light lanthanides in this extraction system, therefore Am and Cm show high separation from middle lanthanides. The separation factors for (Am)/(Sm), (Am)/(Eu), and (Am)/(Gd) are 14.4, 40, and 111, respectively, under the condition of 0.3M DOODA/dodecane and 10 mM TEDGA/ 5M HNO. The high separation of Am and Cm from these lanthanides, having high neutron cross section, is confirmed in HNO-dodecane system without any pH buffer and metal salts.