Abstract:H₂TiO₃ was obtained from the acid-modified adsorbent precursor Li₂TiO₃, which was synthesized by a solid-phase reaction between TiO₂ and Li₂CO₃. The extraction ratio of Li⁺ from Li₂TiO₃ was 98.86%, almost with no Ti⁴⁺ extracted. The effects of lithium titanium ratio, calcining temperature and time were investigated on the synthesis of Li₂TiO₃. Li₂TiO₃, H₂TiO₃ and the adsorbed Li⁺ adsorbent were characterized by XRD and SEM. The lithium adsorption properties were investigated by the adsorption kinetics and adsorption isotherm. The results indicate that H₂TiO₃ has an excellent adsorptive capacity for Li⁺. Two simplified kinetic models including the pseudo-first-order and pseudo-second-order equations were selected to follow the adsorption processes. The rate constants of adsorption for these kinetic models were calculated. The results show that the adsorption process can be described by the pseudo-second-order equation, and the process is proved to be a chemical adsorption. The adsorption process that H₂TiO₃ adsorbs Li⁺ in LiCl solution well fits the Langmuir equation with monolayer adsorption.

Key words: Li⁺ adsorbent; Li₂TiO₃; adsorption property; kinetic models; monolayer adsorption; TiO₂; Li₂CO₃