薄层油膜层流萃取分离稀土铕和钆

Separation of Adjacent Rare Earths Europium and Gadolinium by Thin Oil Film Extraction

相邻稀土元素铕(Eu)和钆(Gd)的物理化学性质相似,分离尤其困难。常规平衡萃取方法Eu、Gd的分离效率低。采用薄层油膜层流萃取法,不仅可以加快界面更新速度,还可以控制水相层流运动。以双功能离子液体[A336][P204]为萃取剂,发现萃取剂浓度升高和油膜层厚度减小,均有利于萃取,但不利于分离。而水相流速增加,不利于萃取,但有利于分离。基于薄层油膜层流萃取法,依靠Eu、Gd传质速度的差异,可以实现动力学调控相邻稀土的分离。

The physical and chemical properties of adjacent rare earth elements Eu and Gd are similar,so their separation is particularly difficult.By the conventional equilibrium extraction method,the separation efficiency of Eu and Gd is low.The method of thin layer oil film laminar flow extraction can not only accelerate the interface renewal speed,but also control the laminar flow of water phase.Bifunctional ionic liquid[A336][P204]was used as the extractant.It is found that the increase of extractant concentration and the decrease of oil film thickness are both beneficial to extraction,but not conducive to mutual separation of Gd Eu.However,the increase in flow velocity of water phase is not favorable for extraction,but is conducive to separation.Based on thin layer oil film laminar flow extraction method,it is expected to achieve the kinetic enhanced separation of adjacent rare earths Eu and Gd depending on their difference of mass transfer rates.