尖晶石型锂锰氧化物离子筛的制备方法及构效性能分析

Preparation methods and analyses of structural performance of spinel-type lithium manganese oxide ion sieves

尖晶石型锂锰氧化物离子筛作为一种溶液提锂的吸附材料,具有广阔的应用前景,而在实际研究与推广应用进程中,也存在着一些问题。文章结合已有的研究,详细介绍了目前研究最多的三种锂锰氧化物离子筛前体(Li Mn2O4、Li4Mn5O12和Li1.6Mn1.6O4)和对应锰氧化物离子筛(λ-Mn O2、Mn O2·0.31H2O和Mn O2·0.5H2O)制备方法的比较;重点分析了三种前体和离子筛的晶体结构特征以及离子筛吸附性能的本质区别;对粉状离子筛的成型(造粒和成膜)作了详细阐述并与粉状离子筛的性能进行了比较;最后总结了目前锂锰氧化物离子筛实际吸附量与理论吸附量的差异和选择性以及离子筛溶损等现存的问题。随着离子筛成型技术的改善和掺杂新型离子筛的开发,有望制备工业化应用的海水提锂吸附剂。

As a type of adsorbents for extracting lithium from solution,spinel-type lithium manganese oxides are the most promising ones for the industrial application of lithium. However,there still exist several problems in the process of practical research and application. The comparison of preparation methods for three types of lithium manganese oxide ion sieve precursors （ LiMn2O4、Li4Mn5O12 and Li1.6Mn1.6O4 ） and corresponding ion sieves （ λ-MnO2、MnO2？0.31H2O and MnO2？0.5H2O ） were introduced in detail. The distinction of crystal structures and characteristics for the precursors and adsorption capabilities for the ion sieves were analyzed emphatically. Moreover,the granule/membrane formation of powder lithium ion sieves and their application were summarized,and the difference of adsorption capacities among three forms of lithium ion sieves was also elaborated. Finally,the difference of adsorption capabilities in theory and practice,selectivity and dissolved loss for lithium ion sieves were summed up in detail,meanwhile,the ion sieve adsorbents for extraction lithium from seawater could realize industrial application with the improvement of molding technology for powder ion sieves and the development of novel and doped lithium ion sieves.