Application of IPE-23 extractant in the recovery of lithium from lithium-containing waste liquors
The further extraction of lithium ions from waste lithium-ion battery recycling solutions offers both economic and environmental benefits.β-diketone solvent extraction systems have garnered extensive attention due to their excellent lithium extraction capabilities.However,the limited variety of β-diketone extractants currently available results in certain selection constraints.This study conducted theoretical calculations of the molecular surface electrostatic potential of the extractant and the Gibbs free energy change of the lithium extraction reaction using Gaussian 16 and Multiwfn software.The results indicate that substituents such as-NO2,-CF3,and-CN can enhance lithium extraction performance by altering the electrostatic potential extrema of the β-diketone's van der Waals surface.Based on this theoretical foundation,a selective lithium extraction agent,IPE-23,was developed.The impact of operational factors such as extractant concentration,temperature,phase ratio,and base addition was investigated using lithium extraction efficiency,separation ratio,extraction phase separation,and the loss of extractant in the aqueous phase(measured by the chemical oxygen demand in the aqueous phase)as evaluation metrics.Through a process of three-stage countercurrent extraction,three-stage countercurrent washing,and CO2 acidification stripping,the lithium extraction rate reached 97％,with a distribution ratio DLi of 21.90 and a lithium-sodium separation factor of 423.85.The pH of the remaining liquid was 11.3,with a COD of 675.2mg/L,and the lithium concentration in the stripping solution reached 6.66g/L.This study provides technical reference and theoretical support for the efficient recycling and reuse of lithium resources from lithium-containing wastewater.
lithium-containing waste liquidsolvent extractionseparationrecoverylithium extraction by wet method
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