A Novel Group Separation Strategy for Extraction of Multiple Rare-Earth Ions from Complex Leach Solu

• 作 者: Na Sui Kun Huang Huizhou Liu
• 机 构: State Key Laboratory of Biochemical Engineering,Key Laboratory of Green Process and Engineering,Inst
• 出 处: 第七届国际分离科学与技术会议(Proceedings of the 7th International Conferen
• 发表日期: 2013年9期

　　Solvent extraction is one of the most important techniques for separation and purification of rare-earths [1].In practical industrial-scale process,however,group-separation of rare-earth ions by traditional aqueous-organic biphasic system have to be conducted by repeated liquid-liquid twp phase equilibrating at carefully selected solution pH values.Repeated adjustments of solution pH value are always required to achieve separation of light,middle and heavy rare-earth ions [2,3].This work aims to solve purification of rare earth from such impurities as Al,Fe and Si,as well as one-step separation of multiple rare-earth ions by a proposed novel strategy of three-liquid-phase extraction (TLPE).The three-liquid-phase system used for TLPE is composed of organic top phase,polymer-rich middle phase and salt-rich bottom phase.Experimental results indicate that co-existed non rare-earth impurities,such as Al(III),Fe(III),Si(IV),can be selectively enriched into the top organic phase and polymer-rich middle phase of TLPS,respectively,while most rare-earth ions remain in salt-rich bottom phase.And then,group separation of light,middle and heavy rare-earth ions,such as La(III),Eu(III) and Yb(III),respectively into bottom aqueous phase,polymer middle phase and top organic phase can be achieved after removing impurities.The present works indicate that three-liquid-phase extraction is a promising separation method to treat the complex solution containing multiple rare earths and non rare-earth impurities.