离子液体参与构筑微乳液膜富集分离稀土元素的基础研究

China possesses the ionic rare earth ore which is rarely in the world. Due to the scarcity of this resource, strengthening the enrichment and separation of rare earth in low-concentration leaching liquor is a key issue which needs to be solved urgently in its smelting. This project is aimed at the low concentration medium and heavy rare earth solution produced during the mining of ionic rare earth ore, and it is proposed to use ionic liquid as the surfactant and non-polar component to construct an ionic liquid-based microemulsion membrane system to enrich and separate rare earth. In this project, the physicochemical properties and microstructure of ionic liquid-based microemulsion membrane system will be studied, to determine the formation mechanism of ionic liquid-based microemulsion membrane. The interfacial properties and microstructure of ionic liquid-based microemulsion membrane-medium and heavy rare earth ions system will be studied, to reveal the structure-effect relationship of ionic liquid-based microemulsion membrane-medium and heavy rare earth ions separation system. The variation law of enrichment and separation of medium and heavy rare earth ions by ionic liquid-based microemulsion membrane will also be investigated, to construct mass transfer process model and thermodynamic model, and to explore the extraction mechanism. The research of this project can obtain the theoretical system of enrichment and separation medium and heavy rare earth ions by ionic liquid-based microemulsion membrane, and provide abundant technical theoretical basis for the high-efficiency and high-value utilization of ionic rare earth ore. It has important theoretical and practical significance for rare earth separation science.

我国拥有世界罕见的离子型稀士矿，由于该资源的稀缺性，加强对低浓度浸出液中稀土的富集分离是其冶炼中亟待解决的重点问题。本项目针对离子型稀土矿开采过程中产生的低浓度中重稀土溶液，拟采用离子液体作为微乳液中表面活性剂和非极性组分构筑离子液体基微乳液膜体系富集分离稀土。本项目通过研究离子液体基微乳液膜体系的物理化学性质和微观结构，探明离子液体微乳液膜的形成机制；研究离子液体基微乳液膜-中重稀土离子体系的界面性质以及微结构，揭示离子液体基微乳液膜-中重稀土离子分离体系的构效关系；通过研究离子液体基微乳液膜富集分离中重稀土离子过程中的变化规律，构建传质过程模型和热力学模型，探明萃取机理。本项目的研究可以获得离子液体微乳液富集分离中重稀土的理论体系，为离子型稀土矿高效高值化利用提供丰富的技术理论依据，对于稀土分离科学具有重要的理论与实际意义。

针对离子型稀土矿物、离子型稀土尾矿和多种元素伴生共存稀土矿的开采及加工产生的大量低浓度稀土溶液严重影响稀土冶炼的可持续发展的现状，加强对低浓度浸出液中稀土的富集分离是稀土冶炼中亟待解决的重点问题。本项目主要采用微乳液法富集分离并回收稀土，主要开展了三方面的研究。首先，以OP-4、OP-7、OP-10、AOT、SDBS等为表面活性剂，构筑了不同非离子、阴离子型微乳液体系，采用电导率、表面张力及FTIR等方法研究其结构特征，确定所制备的微乳液体系为W/O结构。其次，采用构筑的微乳液体系富集分离稀土元素，获得了微乳液富集分离稀土的构效关系和理论体系，得到最佳的工艺参数，探明了离子液体对微乳液富集分离稀土的影响。最后，研究了AOT/正丁醇/环己烷微乳液体系回收稀土的方法及工艺流程，并以稀土Ho为例，得到产物为立方晶体结构的纳米Ho2O3。本项目为探索稀土分离科学的新技术提供了理论指导和技术支撑，同时为离子型稀土矿以及多种元素伴生共存稀土矿高效高值化利用提供了丰富的技术理论依据。