LAUSR

Abstract The prepared titanium type lithium ion sieve H x TiO 3 are characterized and tested as adsorbents for selective adsorption of lithium from high Mg-containing brine. The maximum adsorption capacities of Li + , Na + , K + , Ca 2 + and Mg 2 + ions onto H x TiO 3 reached 36.34, 1.93, 1.99, 2.58 and 3.53 mg/g, respectively, under the initial pH 8.8 at 25 °C for 24 h. Adsorption isotherms and kinetic analysis indicated that the adsorption of Li + ions and other cations onto H x TiO 3 followed Langmuir isotherm model and pseudo-second order kinetic equation. A diffusion model simulation showed that the Li + ions had the highest external diffusion coefficients (7.7 × 10 − 2  cm s − 1 ) while the other cations had small effect on the adsorption rate of Li + . The Biot number was > 100 signified that these ions adsorption onto H x TiO 3 were controlled by the internal diffusion. The separation factors ( α ) of Li + over other cations were much > 1. In particular, the α value of Li + over Mg 2 + reached 4783, indicating the high selectivity for Li + . In addition, the Li + ion adsorption capacity kept constant during the six adsorption-desorption cycles and molar ratio of Mg to Li of eluents was as low as 0.08, indicating that the H x TiO 3 ion sieve could effectively extract Li + from the enriched brine.