Novel lithium ion-sieve spinning fiber composite of PVDF-HMO for lithium recovery from geothermal water

With the increasing application of the industrialization of lithium and its derivatives, there has been a surge of interest in recovering this resource from liquid sources. However, synthesizing adsorbents with industrial significance is still a significant challenge. Herein, the precursor Li1.6Mn1.6O4 of H1.6Mn1.6O4 powder absorbent with the highest theoretical adsorption capacity and the lowest Mn dissolution loss rate was first synthesized by hydrothermal or high-temperature solid phase method. The commercialized wet spinning apparatus, which has convenient operation and a simple process, was used to prepare PVDF/HMO spinning fiber to recover lithium resources from geothermal water. It has a large specific surface area of 31.45 m2 g-1 and a pore size of 9.04 nm, and the adsorption capacity was 14.95 mg g-1, with the distribution coefficient of Li+ being 1404.96 mL g-1. Furthermore, the equilibrium was reached within just 2 h at pH 12, and the elution time was just 1 h. Even after the fifth cycle, the adsorption capacity remained high at 14.21 mg g-1. These characteristics indicate that the new material has excellent application potential for lithium recovery from geothermal water.