多组分协同萃取体系应用于高镁锂比盐湖卤水提锂  

Recovery of Lithium from High Magnesium-Lithium Ratio Salt Lake Brines Utilizing a Multi-component Synergistic Extraction Approach

作　　者：牛犁 郭纵 张驰 邹小平 马浩 王海北 NIU Li;GUO Zong;ZHANG Chi;ZOU Xiaoping;MA Hao;WANG Haibei(BGRIMM Technology Group,Beijing 100160,China)

机构地区：[1]矿冶科技集团有限公司,北京100160

出　　处：《有色金属(中英文)》2025年第3期383-392,共10页Nonferrous Metals

基　　金：云南省科技厅重大科技专项计划(202302AF080004);北京市科学技术委员会国际科学家项目(IS24024)。

摘　　要：针对高镁锂比盐湖卤水,采用多组分协同萃取体系选择性萃取锂。结果表明,有机相组成40%TBP-20%P204-40%260^(#)溶剂油、Fe/Li摩尔比1.5、相比O/A=2时,单级Li^(+)萃取率77.5%,三级Li^(+)萃取率91.88%,单级萃取镁锂分离系数43.29,三级镁锂分离系数79.94,确定O/A=40为最佳洗涤相比,O/A=20为最佳反萃相比,Li^(+)和Mg^(2+)反萃率分别为75.17%和84.97%;有机相组成40%TBP-30%P507-30%260~#溶剂油、Fe/Li摩尔比1.7、相比O/A=3时,单级Li^(+)萃取率79%,三级Li^(+)萃取率91.88%,单级萃取镁锂分离系数31.56,三级萃取镁锂分离系数53.68,确定O/A=50为最佳洗涤相比,O/A=30为最佳反萃相比,Li^(+)和Mg^(2+)反萃率为53.09%和8.47%。采用红外光谱对多组分协同萃取体系萃锂反应机理进行研究,结果表明,起萃取作用的是P=O磷氧酰键,萃取过程中FeCl_(4)^(-)与Li^(+)等离子及TBP结合,洗涤及反萃过程中部分P=O键的萃合物可能从锂、镁等元素变为铁元素。For high magnesium-lithium ratio brine from salt lakes,a multi-component synergistic extraction system was used for the selective extraction of lithium.The results show optimized conditions are organic phase composition of 40%TBP-20%P204-40%260^(#)solvent oil,Fe/Li molar ratio of 1.5,O/A=2,Li^(+)extraction rate at single-stage of 77.5%,the magnesium lithium separation coefficient of 43.29,Li^(+)extraction at three-stage rate of 91.88%,the magnesium lithium separation coefficient of 79.94.The optimal washing ratio and stripping ratio O/A are 40 and 20,respectively,while the stripping rates of Li^(+)and Mg^(2+)are 75.17%and 84.97%,respectively.Under optimized conditions,including an organic phase composition of 40%TBP-30%P507-30%260#solvent oil,an Fe/Li molar ratio of 1.7,and an O/A ratio of 3,the single-stage Li^(+)extraction rate reaches 79%,with a magnesium lithium separation coefficient of 31.56,At three stages,the Li^(+)extraction rate increases to 91.88%,and the magnesium-lithium separation coefficient rises to 53.68.The optimal washing and stripping ratios(O/A)are determined to be 50 and 30,respectively.The stripping rates of Li^(+)and Mg^(2+)are 53.09%and 8.47%,respectively.The mechanism of lithium extraction reaction in multi-component synergistic extraction system was studied using infrared spectrum.The results show that the P=O phosphoryl bond played a role in extraction.During the stripping process,FeCl_(4)^(-)combined with Li^(+)and TBP,and some P=O bond complexes may change from lithium,magnesium to iron.

关 键 词：盐湖提锂 P204/P507协同萃取体系 镁锂分离 

分 类 号：TF826.3[冶金工程—有色金属冶金] TS396.5[轻工技术与工程]