一、引言离子交换法是分离希土元素最有效的方法之一。近十几年来,世界各国都进行了很多研究,有定量的分离,也有为制备个别希土元素的分离。离子交换法分离希土元素,一般系将希土元素吸着在阳离子变换树脂上,然后用各种淋洗剂淋洗分离。分离裂变产物中的希土元素,淋洗剂一般采用α-羟基酸类,制备希土则常用柠檬酸、氨三乙酸、乙二胺四乙酸等。由于乙二胺四乙酸(简称EDTA)与个别希土元素的络合物稳定常数的差别较大,因此分离效率较高,淋出液中希土元素的浓度比柠檬酸高 I. INTRODUCTION Ion exchange is one of the most effective ways to separate the rare earth elements. In the past decade or so, many countries in the world have conducted many studies with a quantitative separation as well as the separation of the elements for the preparation of individual earthen elements. Ion exchange method for the separation of rare earth elements, generally Department of the Greek soil adsorption on the cation exchange resin, and then rinsed with a variety of eluent separation. Separation of fission products in the Greek soil elements, eluent commonly used alpha-hydroxy acids, the preparation of the Greek often citric acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid and so on. Due to the large difference in the stability constants of ethylenediaminetetraacetic acid (abbreviated as EDTA) and individual rare earth elements, the separation efficiency is high, and the concentration of the rare earth element in the effluent is higher than that of citric acid