Development of new high-selective solvent extraction method for separation of rare earth metals by using aqueous complexing agent

水络合剂分离稀土金属的高选择性溶剂萃取新方法的开发

• 批准号: 63550708
• 负责人: TERAMOTO Masaaki
• 金额: $ 1.28万
• 依托单位: Kyoto Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550708/
• 关键词: Solvent Extraction; Liquid Membrane; Aqueous Complexing Agent; Rare Earth Metal; Nonequilibrium Separation; 液膜法; 酸性有機リン化合物

In this work, the selective separations of erbium(Er) and yttrium(Y) by both the solvent extraction and the supported liquid membrane were carried out with a complexing agent, diethylenetriaminepentaacetic acid(DTPA) in the aqueous phase. The purpose of this work is to elucidate the separation mechanism and to establish the experimental conditions in which the highest selectivity can be obtained.First, kinetics of the exchange reactions between rare earth metal ions and their DTPA complexes were studied in order to elucidate the dissociation mechanism of the DTPA complexes. The dissociation rate constants of the DTPA complexes are very important for the clarification of the separation mechanism of the solvent extraction and the liquid membrane containing DTPA in the aqueous phase. It was found that the obtained dissociation rate constant of Y-DTPA complex was about 5.8 times that of Er-DTPA complex.Further, the extractions of Er^<3+> and Y^<3+> from an aqueous phase containing DTPA were carried out. The selectivity obtained was about 5.5, which was much larger than that by the usual solvent extraction, 1.43. The selectivities for the various cases were studied in detail. The extraction rates and selectivities were quantitatively analyzed by taking account of the dissociation reaction of DTPA complexes in the aquous stagnant layer.Furthermore, by using the supported liquid membrane system with, DTPA in the aquous feed phase, the separation of Er^<3+> and Y^<3+> was investigated. This separation method has the feature that the highest selectivity can be obtained when the mass transfer accompaning the dissociation reaction of DTPA complexes in the aqueous stagnant layer is rate-determining. The experimental results were satisfactorily simulated.

本文研究了以二乙烯三胺五乙酸（DTPA）为络合剂，采用溶剂萃取和支撑液膜两种方法对铒（Er）和钇（Y）进行选择性分离。本工作的目的是阐明分离机理，并建立能获得最高选择性的实验条件。首先，研究了稀土金属离子与DTPA络合物之间的交换反应动力学，以阐明DTPA络合物的解离机理。DTPA络合物的解离速率常数对于阐明溶剂萃取和含DTPA的液膜在水相中的分离机理是非常重要的。结果表明，Y-DTPA络合物的离解速率常数约为Er-DTPA络合物的5.8倍，并从含DTPA的水相中萃取了Er^<3+>和Y^<3+>。得到的选择性约为5.5，这比通常的溶剂萃取的选择性1.43大得多。详细研究了各种情况下的选择性。在此基础上，研究了DTPA-支撑液膜体系对Er^<3+>和Y^<3+>的分离性能。该分离方法的特点是当DTPA络合物在水相滞留层中的解离反应的传质为速率控制时，可获得最高的选择性。实验结果得到了满意的模拟。

项目成果

H.Matsuyama: "Kinetic Studies on Exchange Reactions between Rare Erth Metal Ions and their Diethylenetriaminepentaacetic Acid Complexes" J.Chemical Engineering of Japan. 22. 460-468 (1989)

H.Matsuyama：“稀土金属离子与其二乙烯三胺五乙酸络合物之间交换反应的动力学研究”J.Chemical Engineering of Japan。

H.Matsuyama: "Extraction mechanism of rare earth metals in the presence of diethylenetriaminepentaacetic acid in aqueous phase" J. Chem. Eng. Japan 22, 627-635, 1989.

H.Matsuyama：“水相中二乙烯三胺五乙酸存在下稀土金属的萃取机理”J. Chem。

H.Matsuyama: "Selectivity Enhancement in the Permeation of Rare Earth Metals through Supported Liquid Membranes by Addition of Diethylene triamine Pentaacetic Aoid to the Aqueous Phasc" J.Membrane Science. 47. 217-228 (1989)

H.Matsuyama：“通过在水相中添加二亚乙基三胺五乙酸来提高稀土金属通过支撑液膜渗透的选择性”J.Membrane Science。

H.Matsuyama: "Kinetic studies of exchange reactions between rare earth metal ions and their diethylenetriaminepentaacetic acid complexes" J. Chem. Eng. Japan. 22. 460-468 (1989)

H.Matsuyama：“稀土金属离子与其二乙烯三胺五乙酸络合物之间交换反应的动力学研究”J. Chem。

H.Matsuyama: "Extraction Mechanism of Rare Earth Metals in the Presence of Diethy lene tri amine pentaacetic Acid in Aqucous phase" J.Chemical Engineering of Japan. 22. 627-635 (1989)

H.Matsuyama：“水相中存在二乙烯三胺五乙酸时稀土金属的萃取机理”J.Chemical Engineering of Japan。