Synthesis of granulated Li/Al-LDHs adsorbent and application for recovery of Li from synthetic and real salt lake brines

Powder Li/Al-layered double hydroxides (LDHs) of Li 2 Al 4 (CO 3 )(OH) 12 ·3H 2 O were hydrothermally synthesized in one pot with sodium alginate as a structure modifier and granulated by crosslinked sodium alginate. The powder and granulated Li/Al-LDHs lithium adsorbents were characterized by FT-IR spectroscopy, XRD, SEM, TEM, XPS, and porosity. The adsorption-desorption performance of the granulated Li/Al-LDHs adsorbents was evaluated. Adsorption isotherm , adsorption kinetics , adsorption thermodynamics were investigated. The effects of solution pH, temperature, and the electrolytes (NaCl, Na 2 SO 4 , MgCl 2 , and KCl) on lithium adsorption, and the dissolution of granulated Li/Al-LDHs adsorbents after cyclic adsorption-desorption were also investigated. The granulated Li/Al-LDHs adsorbed 14.5 mg/g of lithium from the brine of East Taigener Salt Lake with a lithium concentration of 1400 mg/L. The granulation of powder Li/Al-LDHs by crosslinked alginate greatly reduced the dissolution of powder Li/Al-LDHs. The granulated Li/Al-LDHs adsorbents prepared in this report are promising materials for Li + extraction from salt lake brines.