高镁锂比盐湖老卤萃取提锂工艺研究

根据盐湖老卤萃取提锂工艺特点及现有工艺与产业化实施过程中暴露的问题, 利用“70%TBP-30%200^#溶剂油”萃取体系设计了“5级逆流萃取-3级逆流洗涤-2级逆流反萃”盐湖卤水提锂工艺流程。在该工艺下, Li/Mg分离系数达到了141.42。反萃液中Li浓度达到25.35 g/L, 萃余液中Li含量低于0.05 g/L。原液中的锂被充分提取, 镁被有效排除, 达到了在高镁锂比盐湖卤水中高效提锂的目的。

Extraction of Lithium from Salt-Lake Brine with High Mg/Li Ratio

According to characteristics and problems in the industrialization of existing technique process for Li extraction from salt-lake brine, a process consisting of five-stage countercurrent extraction, three-stage countercurrent stripping and two-stage countercurrent reverse extraction for Li extraction from salt lake brine was designed by using an extraction system of 70%TBP-30%200^# solvent oil. This process can lead to the separation coefficient of Li/Mg at 141.42 and the strip liquor with Li concentration at 25.35 g/L, with Li content in the extract liquor less than 0.05 g/L. It is shown that the purpose of efficiently extracting Li from salt-lake brine with high Mg/Li ratio can be actualized with Li element in the stock solution fully extracted and Mg effectively removed.