面向盐湖卤水提锂的含对称性结构络阴离子共萃剂的作用机理及应用基础研究

Lithium plays a crucial role in modern industrial and science and technology fields, especially in energetically developing nuclear industrial and new energy fields. In this project, by the adoption of combination of liquid-liquid extraction equilibrium experiment and model calculation, the mechanism of synergistic extraction between TBP and ketone diluents, the mechanism and key factor of the extraction of lithium ion with the hydrophobic ionic liquid as the co-extraction agent formed with complex anion of symmetric stereochemical structure, the basic rules and internal mechanism for the influences of species, charge quantity and configuration of the complex anion of symmetric stereochemical structure on the structure, hydrophobicity and Li selectivity of the complex and the establishment of the methods for selecting, designing and synthesizing the co-extraction agent to replace FeCl3 which can solve a series of problems by the introduction of Fe will be mainly studied for the recovery of Li from salt lake brine with high salinity and Mg/Li ratio that needs to be addressed urgently. Finally, with self-owned independent intellectual property rights, an easy operating, highly controllable, economic and reasonable separation technology based on solvent extraction for lithium recovery from salt lake brine with high Mg/Li ratio can be established for the industrial application, which will be of great importance to extension of salt lake industry chain, cycle development and utilization of salt lake resources and promotion of rapid development of nuclear industrial and new energy fields.

锂在现代工业及科学技术领域占有非常重要的地位，尤其是正大力发展的核工业和新能源领域，本项目针对目前急需解决的具有高盐度、高镁锂比的盐湖卤水提锂的问题，采用液液萃取平衡实验和模型计算相结合的研究方法，重点研究磷酸三丁酯与酮类稀释剂的协萃机理，含有对称性立体结构络阴离子的疏水性离子液体作为共萃剂用于提取锂离子的机理及关键因素，不同种类、不同电荷量、不同构型的对称性结构络阴离子对络合物的结构、疏水性以及锂的选择性影响的基本规律和内在机理，筛选、设计或合成用于取代FeCl3的共萃剂方法的建立，解决由于铁的引入带来的一系列问题，最终期望形成一项具有自主知识产权、操作简便、高效可控、经济合理的用于高镁锂比盐湖卤水中锂离子的基于溶剂萃取法的分离提取技术，为工业应用提供指导，将对拓展盐湖产业链，实现盐湖资源可循环开发利用，促进核工业和新能源领域飞速发展具有重要的科学意义。

针对我国高镁锂比盐湖卤水提锂难度非常大的问题，通过萃取平衡试验，结合分析测试和模拟计算手段，重点研究了酮类化合物与TBP的协萃机理、含对称性立体结构络阴离子的功能性疏水性离子液体和盐类化合物作为共萃剂用于萃取提锂的内在机理和构效关系。取得了如下成果：1）验证了大多数酮类化合物用作稀释剂可有效消除第三相，揭示了酮类化合物与TBP间的协萃机理；2）设计合成两种离子液体和筛选的一种盐类化合物用作共萃剂用于萃取提锂，优化了萃取工艺条件，通过分析测试和模拟计算手段揭示了新型含对称性立体结构的络阴离子的共萃剂萃锂的内在机理；提出不同结构、不同大小和不同带电荷量的络阴离子对于提锂效果和工艺稳定性的影响基本规律和构效关系。研究成果对于拓展盐湖产业链和实现盐湖资源综合利用具有重要的科学意义和显著的应用前景。项目执行期间，在AIChE J, Chem Eng J, Ind Eng Chem Res, ACS Sustain Chem Eng等本领域顶级期刊发表SCI收录论文25篇，申请中国发明专利2项，在国内会议做口头报告3次，培养硕士毕业生3名。