Lin Sen, Pan Yanan, Du Jianglong, Yang Yong, Su Haiping, Yu Jianguo
National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, Shanghai, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, Shanghai, China.
J Colloid Interface Sci. 2022 Dec;627:872-879. doi: 10.1016/j.jcis.2022.07.116. Epub 2022 Jul 21.
Lithium-aluminum layered double hydroxides (Li/Al-LDHs) are the only industrial adsorbents for Li extraction from Mg/Li ratio brines dependent on the special neutral desorption without dissolution damage. In this work, Li/Al-LDHs with different interlayer water contents were designed for the investigation of correlation between interlayer water and Li adsorption performances in high Mg/Li ratio brines. On the one hand, the Li adsorption capacity of Li/Al-LDHs in the Qarham Salt Lake old brine with a Mg/Li ratio exceeding 300 presented a positive correlative relation with the interlayer water content, rising from 1.05 mg/g to 7.89 mg/g as the interlayer water content increased from 5.52% to 18.18%. On the other hand, the interlayer water content would not affect the structure stability of Li/Al-LDHs, while the interlayer spacing was lessened with less interlayer water resulting in an uptrend to the adsorption selectivity on account of the depressed confinement effect. The density functional theory (DFT) calculation further indicated that LiCl was easier to enter the structure of Li/Al-LDHs with more interlayer water in view of the greater interaction energy.
锂铝层状双氢氧化物（Li/Al-LDHs）是唯一一种用于从镁锂比卤水中提取锂的工业吸附剂，其依赖于特殊的中性解吸且不会造成溶解损伤。在本工作中，设计了具有不同层间水含量的Li/Al-LDHs，以研究层间水与高镁锂比卤水中锂吸附性能之间的相关性。一方面，在镁锂比超过300的察尔汗盐湖老卤水中，Li/Al-LDHs的锂吸附容量与层间水含量呈正相关关系，随着层间水含量从5.52%增加到18.18%，锂吸附容量从1.05 mg/g上升至7.89 mg/g。另一方面，层间水含量不会影响Li/Al-LDHs的结构稳定性，而层间水较少时层间距会减小，由于受限效应减弱，导致吸附选择性呈上升趋势。密度泛函理论（DFT）计算进一步表明，鉴于相互作用能更大，LiCl更容易进入层间水较多的Li/Al-LDHs结构。
