School of Metallurgical Engineering, Anhui University of Technology, Ma'anshan, 243032, PR China.
School of Metallurgical Engineering, Anhui University of Technology, Ma'anshan, 243032, PR China; Low-Carbon Research Institute, Anhui University of Technology, Ma'anshan, 243032, PR China.
J Environ Manage. 2022 May 15;310:114705. doi: 10.1016/j.jenvman.2022.114705. Epub 2022 Feb 22.
The present study has proposed a selective Li extraction process using a novel extractant of dibenzo-14-crown-4 ether functionalized with an alkyl C16 chain (DB14C4-C16) synthesized based on the ion imprinting technology (IIT). Theoretical analysis of the possible complexes formed by DB14C4-C16 with Li and the competing ions of Na, K, Ca and Mg was performed through density functional theory (DFT) modeling. The Gibbs free energy change of the complexes of metal ions with DB14C4-C16 and water molecules were calculated to be -125.81 and -166.01 kJ/mol for lithium, -55.73 and -117.77 kJ/mol for sodium, and -196.02 and -291.52 kJ/mol for magnesium, respectively. Furthermore, the solvent extraction experiments were carried out in both single Li and multi-ions containing solutions, and the results delivered a good selectivity of DB14C4-C16 towards Li over the competing ions, showing separation coefficients of 68.09 for Ca-Li, 24.53 for K-Li, 16.32 for Na-Li, and 3.99 for Mg-Li under the optimal conditions. The experimental results are generally in agreement with the theoretical calculations.
本研究提出了一种使用新型萃取剂二苯并-14-冠-4 醚功能化的十六烷基链（DB14C4-C16）的选择性锂提取工艺，该萃取剂是基于离子印迹技术（IIT）合成的。通过密度泛函理论（DFT）建模对 DB14C4-C16 与 Li 以及 Na、K、Ca 和 Mg 的竞争离子可能形成的配合物进行了理论分析。计算了金属离子与 DB14C4-C16 和水分子形成配合物的吉布斯自由能变化，结果表明锂的吉布斯自由能变化分别为-125.81 和-166.01 kJ/mol，钠为-55.73 和-117.77 kJ/mol，镁为-196.02 和-291.52 kJ/mol。此外，在单 Li 和多离子含溶液中进行了溶剂萃取实验，结果表明 DB14C4-C16 对 Li 具有良好的选择性，对竞争离子的分离系数分别为 Ca-Li 为 68.09、K-Li 为 24.53、Na-Li 为 16.32 和 Mg-Li 为 3.99，在最佳条件下。实验结果与理论计算基本一致。
