LIX54/Cyanex923从含锂硫酸钠溶液中协同萃取分离锂钠的研究  

Study on Separation of Lithium from Sodium in Lithium-Containing Sodium Sulfate Solution Using a Synergistic Extraction System of LIX54 and Cyanex923

作　　者：何卓 张贵清 曾理 关文娟 巫圣喜 李青刚 曹佐英 HE Zhuo;ZHANG Gui-qing;ZENG Li;GUAN Wen-juan;WU Sheng-xi;LI Qing-gang;CAO Zuo-ying(Key laboratory of Metallurgical Separation Science and Engineering,School of Metallurgy and Environment,Central South University,Changsha 410083,China)

机构地区：[1]中南大学冶金与环境学院冶金分离科学与工程重点实验室,湖南长沙410083

出　　处：《稀有金属与硬质合金》2023年第5期8-14,27,共8页Rare Metals and Cemented Carbides

摘　　要：针对目前废旧电池正极材料湿法回收工艺中锂回收率低和锂钠分离困难等问题,提出了一种可从含锂硫酸钠溶液中选择性提取锂的协同萃取体系LIX54/Cyanex923。实验结果表明,对于含锂0.5 g/L、钠50 g/L的模拟料液,采用0.4 mol/L LIX54+0.2 mol/L Cyanex923+磺化煤油的有机相,在O/A相比1∶1、平衡pH值12.5、温度30℃和时间10 min的条件下锂的单级萃取率达98.72%,βLi/Na可达1578。在相比O/A=1∶5、平衡pH值12.5条件下经三级模拟逆流萃取,99%以上的锂被萃取,萃余液中锂的含量小于0.01 g/L。采用1 mol/L HCl在O/A相比8∶1条件下经过两级逆流洗涤,近98%的钠被洗脱,有机相中仅留下0.05 g/L钠。洗后负载有机相用3 mol/L HCl在相比O/A=6∶1下进行两级逆流反萃,锂的反萃率达99%以上,反萃液中锂的浓度被富集到16.93 g/L。LIX54/Cyanex923协同萃取体系能有效地从含锂硫酸钠溶液中选择性回收锂,实现锂与钠的深度分离及锂的高倍富集回收。Aiming at the problems of low lithium recovery efficiency and difficult lithium-sodium separation in the current wet recycling process of spent battery cathode materials,a synergistic extraction system of LIX54/Cyanex923 was proposed for the selective extraction of lithium from lithium-containing sodium sulfate solution.The experimental results show that for the synthetic feed solution containing 0.5 g/L Li and 50 g/L Na,98.72%of lithium in a single contact is extracted by the organic phase consisting of 0.4 mol/L LIX54,0.2 mol/L Cyanex923,and sulfonated kerosene with an O/A ratio of 1∶1 and equilibrium pH of 12.5 at 30℃for 10 min,resulting in a separation factor of lithium from sodium reaching 1578.After three-stage simulated counter-current extraction at an O/A ratio of 1∶5 and equilibrium pH of 12.5,over 99%of lithium is extracted,leaving less than 0.01 g/L Li in raffinate.After two-stage counter-current scrubbing with 1 mol/L HCl at an O/A ratio of 8∶1,nearly 98%sodium is elated,leaving 0.05 g/L Na in the organic phase.After two-stage counter-current scrubbing with 1 mol/L HCl at an O/A ratio of 8∶1,nearly 98%sodium is eluted,leaving 0.05 g/L Na in the organic phase.After scrubbing,the loaded organic phase undergoes two-stage counter-current stripping with 3 mol/L HCl at an O/A ratio of 6∶1.The stripping rate of lithium reaches over 99%and the lithium concentration is enriched up to 16.93 g/L in the strip liquor.The LIX54/Cyanex923 synergistic extraction system can effectively recover lithium from lithium-containing sodium sulfate solution selectively and realize the deep separation of lithium from sodium and the enrichment of lithium at high magnification.

关 键 词：锂 钠 协同萃取 LIX54 Cyanex923 

分 类 号：TF826.3[冶金工程—有色金属冶金]