Fabrication of Spinel-Type H4Ti5O12 Ion Sieve for Lithium Recovery from Aqueous Resources: Adsorption Performance and Mechanism

Lithium (Li) ion sieve is considered to have great potential in the selective extraction of Li+ from complex Li+-containing brine owing to its cost-effectiveness, excellent adsorption performance, and environmental friendliness. Nevertheless, the defects of complex regulation and control of technological parameters in the preparation process of Li ion sieve and poor recycling efficiency limit its application. In this study, spinel-type H4Ti5O12 ion sieves (HTO) were successfully prepared through a high-temperature solid-state method for recovering Li+ from aqueous resources. Through the experiment of optimizing the key preparation process parameters of HTO, it was found that the optimum preparation conditions were as follows: lithium ion source of CH3COOLi‧H2O, calcination temperature of 800 °C, and acid (HCl) washing concentration of 0.3 mol/L. The uptake of Li+ by HTO aligned with the pseudo-second-order kinetic model, which was a chemical adsorption process controlled by reversible Li–H ion exchange reaction. HTO exhibited extremely high regeneration cycle characteristics, and after five cycles, it retained 96.06% of its initial adsorption capacity. The present work highlighted that spinel-type HTO has high industrial application potential in the field of Li+ recovery from oilfield brine.