Adsorption performance and mechanism of Li+ from brines using lithium/aluminum layered double hydroxides-SiO2 bauxite composite adsorbents

Frontiers in Chemistry

Chemistry

Yongsheng Zhang¹  Cheng Qian¹  Baoling Gui¹  Enyuan Xing¹  Mianping Zheng¹ 

[1] Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing, China;Key Laboratory of Saline Lake Resources and Environment, Ministry of Land and Resources, Beijing, China;

关键词: LDH-Si-BX;    brines;    Li + adsorption behavior;    mechanism;    regeneration;   

DOI  :  10.3389/fchem.2023.1265290

 received in 2023-07-22, accepted in 2023-10-06,  发布年份 2023

来源: Frontiers

【 摘 要 】

A combined method of solid-phase alkali activation and surface precipitation was used to prepare the lithium/aluminum layered double hydroxides-SiO2 loaded bauxite (LDH-Si-BX) and applied to adsorb Li+ in brines. In the study, various characterization techniques such as SEM, XRD, BET, Zeta potential, and x-ray photoelectron spectroscopy (XPS) were applied to characterize and analyze the adsorbents. The adsorption-desorption performance of LDH-Si-BX for Li+ in brines was systematically investigated, including adsorption temperature, adsorption time, Li+ concentration, and regeneration properties. The results indicated that the adsorption kinetics were better fitted by the pseudo-second-order model, whereas the Langmuir model could match the adsorption isotherm data and the maximum Li+ capacity of 1.70 mg/g at 298K. In addition, in the presence of coexisting ions (Na+, K+, Ca2+, and Mg2+), LDH-Si-BX showed good selective adsorption of Li+, and the pH studies demonstrated that the adsorbents had better Li+ adsorption capacity in neutral environments. In the adsorption process of real brines, LDH-Si-BX had a relatively stable adsorption capacity, and after 10 cycles of adsorption and regeneration, the adsorption capacity decreased by 16.8%. It could be seen that the LDH-Si-BX adsorbents prepared in this report have the potential for Li+ adsorption in brines.

【 授权许可】

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Copyright © 2023 Qian, Zheng, Zhang, Xing and Gui.