Enhanced separation of yttrium,erbium and thulium with P507 induced by complexation kinetics of DTPA  

DTPA配合动力学诱导P507强化分离钇、铒和铥

作　　者：Na SUI Shu-kai MIAO Hao SHEN Kai-hui CUI Jia-qi WANG Kun HUANG 隋娜;苗书凯;沈昊;崔凯辉;王佳琦;黄焜(北京科技大学冶金与生态工程学院,北京100083;自然资源部离子型稀土资源与环境重点实验室,赣州341000)

机构地区：[1]School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China [2]Key Laboratory of Ionic Rare Earth Resources and Environment,Ministry of Natural Resources,Ganzhou 341000,China

出　　处：《Transactions of Nonferrous Metals Society of China》2025年第4期1338-1349,共12页中国有色金属学报(英文版)

基　　金：funded by Key Laboratory of Ionic Rare Earth Resources and Environment,Ministry of Natural Resources,China(No.2022IRERE206);financially supported by the National Natural Science Foundation of China(Nos.51904027,52074031)。

摘　　要：Based on a non-equilibrium kinetic extraction technique,the complexation kinetics of diethylenetriamine-pentaacetic acid(DTPA)with rare earth(RE)ions was investigated with different adding sequences of DTPA.The results indicated that the separation factors ofβTm/Er andβY/Er were higher when adding DTPA at the start of extraction than those before extraction.The extraction order for Y,Er and Tm was Tm>Y>Er.The root of discrepancy in complexation kinetics of Y,Er and Tm ions with DTPA and the enhanced kinetic separation mechanism were elucidated from the forward complex formation and reverse dissociation rates by the stopped-flow spectrophotometric technique.The apparent complexation rate constants began to decrease gradually with the increase of aqueous pH,while increased with increasing DTPA concentration.The emergence of extraction priority order as Tm>Y>Er was verified according to the calculated reaction kinetic constants of Y,Er and Tm at different pH values.基于非平衡动力学萃取技术,研究了采用不同的二乙三胺五乙酸(DTPA)添加顺序时稀土离子与DTPA的配合动力学。结果表明,在萃取开始时加入DTPA,稀土Tm/Er和Y/Er之间的分离系数均高于萃取前预先加入DTPA时对应的分离系数。稀土Y、Er、Tm离子的萃取顺序为Tm>Y>Er。通过停留光谱法从正向配合物形成速率和逆向配合物解离速率上查明了Y、Er、Tm离子与DTPA配合动力学差异的本质和动力学强化分离机理。研究发现,表观配合速率常数随着水溶液p H的增加逐渐降低,而随着DTPA浓度的增加而逐渐增加。根据计算得到的Y、Er、Tm在不同p H值下的反应动力学常数,验证了萃取优先顺序为Tm>Y>Er。

关 键 词：rare earths extraction complexation kinetics diethylenetriaminepentaacetic acid(DTPA) stopped-flow spectrophotometric technique 

分 类 号：TF845[冶金工程—有色金属冶金]