# 음이온 교환수지에서의 희토류-EDTA 용리액에 의한 희토류 원소의 분리

Chloride form anion exchange resin was used to separate one of the elements from the rare earth mixture using respectable Ln-EDTA eluent. $Sm^{3+}$, $La^{3+}$ or $Ce^{4+}$ complexed with EDTA was passed through the resin column and eluted with a Sm-EDTA solution as an eluent. Here all the rare earth element ions except $Sm^{3+}$ were passed. Adsorbed $Sm^{3+}$ in resin was eluted with 1.0 M HCl solution. If La-EDTA solution as an eluent was used to separate lanthanum ions, lanthanum ions were eluted together with other rare earth elements. When Ce-EDTA solution was also used for separation of $Ce^{4+}$, it was eluted in the region of other rare earth elements. In the case of Sm-EDTA elution, the elution mechanism was as follows : Absorption : $RCl+Ln-Y^-{\leftrightarrows}RLnY+Cl^-$, Sm-EDTA elution : $RLnY+Sm-Y^-{\leftrightarrows}RSmY+Ln-Y^-$, HCl elution : $RSmY+HCl{\leftrightarrows}RCl+Sm-Y^-$.
Ln-EDTA;$Cl^-$ form anion exchange resin;rare earth element