Advanced PDMS@Li/ZnAl-LDH microspheres for lithium recovery from Qarhan Salt Lake brine with high Mg/Li disparity

This study investigates the synthesis, characterization and adsorption efficiency of PDMS@Li/ZnAl-LDH as a potential adsorbent for lithium recovery from Salt Lake brine with a high Mg/Li ratio. Synthesized via co-precipitation, the adsorbent exhibited excellent stability across a wide range of pH and temperature, along with a well-defined layered crystalline structure. The maximum adsorption capacity of Li + is 14.1 mg/g in lithium brine and 9.4 mg/g in the Qarhan Salt Lake's brine with impressive selectivity, as indicated by separation factors of 215, 838 and 175 for Li + /K + , Li + /Na + and Li + /Mg 2+ , respectively. Microspheres formed by Li/ZnAl-LDH in ultra-pure water exhibited tunable pore size and porosity as compared to Li/Al-LDH, which enhanced the Li + adsorption. Cyclic adsorption and zinc dissolution tests confirmed the adsorbent's excellent reusability with no significant structural degradation. Furthermore, using NaAlO 2 as a precursor reduces cost, making Li/ZnAl-LDH a viable option for large-scale lithium recovery. This work presents a sustainable, cost-effective strategy for lithium recovery with potential industrial applications.