TBP-D2EHPA协萃体系分离盐湖卤水中锂镁  

Separation of lithium and magnesium from salt lake brine by TBP-D2EHPA synergistic extraction system

作　　者：王德卿 王海北[1,2] 谢铿 王子豪 WANG De-qing;WANG Hai-bei;XIE Keng;WANG Zi-hao(Beijing General Research Institute of Mining and Metallurgy,Beijing 102628,China;BGRIMM Technology Group,Beijing 100160,China)

机构地区：[1]北京矿冶研究总院,北京102628 [2]矿冶科技集团有限公司冶金研究设计所,北京100160 [3]矿冶科技集团有限公司,北京100160

出　　处：《矿冶》2022年第3期96-102,共7页Mining And Metallurgy

基　　金：国家重点研发计划项目(2018YFC0604803);矿冶科技集团有限公司科研基金重点项目(电池用关键材料制备技术)。

摘　　要：针对磷酸三丁酯(TBP)-FeCl_(3)萃取体系从镁锂比高的盐湖卤水分离锂镁工艺中存在的反萃酸度高、再生有机相试剂消耗大等问题,筛选出添加二(2-乙基己基)磷酸(D2EHPA)的协萃体系。探究了有机相组成、Fe/Li摩尔比、萃取相比等因素对盐湖卤水中锂镁萃取分离效果的影响。在有机相组成为40%TBP-20%D2EHPA-40%260#溶剂油、Fe/Li摩尔比为1.5、相比O/A=2的优化萃取条件下,单级Li^(+)萃取率达78.56%,锂镁分离系数达46.26。使用水作为洗涤剂及反萃剂,优选了洗涤相比O/A=60及反萃相比O/A=20,单级洗涤及反萃阶段锂镁分离系数分别为46.26和22.97,取得了较好的锂镁分离效果,可为后续扩大试验与工业设计提供依据。Aiming at the problems of high acidity stripping and consumption of a large amount of reagents for organic regeneration in the process of separating lithium and magnesium from salt lake brine with high magnesium-to-lithium ratio by tributyl phosphate(TBP)-FeCl_(3) extraction system,a synergistic extraction system with addition of bis(2-ethylhexyl)phosphate(D2EHPA)was screened out.The effects of organic phase composition,Fe/Li molar ratio,extraction ratio and other factors on the extraction and separation of lithium and magnesium from salt lake brine were systematically investigated.Under the optimal extraction conditions of organic phase composition of 40%TBP-20%D2EHPA-40%260#solvent oil,Fe/Li molar ratio of 1.5,and O/A=2,the single-stage Li^(+) extraction rate reached 78.56%and the lithium-magnesium separation coefficient reached 46.26.Using water as the washing and stripping agent,the washing ratio of O/A=60 and the stripping ratio of O/A=20 were preferred.A good lithium-magnesium separation effect was achieved,providing a basis for subsequent pilot experiments and industrial design.

关 键 词：盐湖卤水 锂 D2EHPA 协同萃取 锂镁分离 

分 类 号：TQ420.6[化学工程] TF826.3[冶金工程—有色金属冶金]