First Granulation of H₄Ti₅O₁₂ Lithium-Ion Sieve Using Two Different Binders for Selective Lithium Extraction

Currently, there remains a lack of efficient and stable granulation strategies for titanium-based lithium-ion-sieved H4Ti5O12 (HTO). Here, we systematically compare chitosan and alginate binders for HTO granulation, developing two novel composite adsorbent microspheres: HTO-CTS and HTO-AL. The results demonstrate that both composite adsorbents exhibit excellent Li+ selectivity in simulated salt-lake brine, with HTO-AL showing a significantly higher distribution coefficient (272.26 mL·g–1) and equilibrium adsorption capacity (32.1 mg·g–1) for Li+ compared to HTO-CTS (197.13mL·g–1, 24.7 mg·g–1). This performance difference also originates from HTO-AL's superior chemisorption-dominant characteristics, as evidenced by its higher fitting degree in the pseudo-second-order kinetic model (R2 = 0.998 vs 0.978). Meanwhile, HTO-AL demonstrates a simpler preparation technology while maintaining 94% of its adsorption capacity (30.2 mg·g–1) after 10 cycles. These comprehensive results demonstrate that the superior performance exhibited by HTO-AL endows this material with significant potential for industrial applications such as lithium extraction from salt lakes.