Preparation Of Hybrid Membrane For Uptaking Lithium And Its Adsorption Properties

With the continuous development of people and rapidly progress of science andtechnology, the demand for resources is rising, especially for lithium. Theexploration of lithium resources for liquid lithium resources shows great significateto contend with the raising demand for lithium. The Spinel-type Manganese OxideH1.6Mn1.6O4is considered to be the most promising material for adsorbing lithiumfrom lithium containing waters. The ion-sieve adsorbent as the adsorption materialshows high lithium adsorption capacity and good selectivity. Its also hasdisadvantages, such as difficult to control and small particle size. Study onpreparation of H1.6Mn1.6O4and its introduction application has a bright future.A new spinel-type lithium manganese oxide ion-sieve---H1.6Mn1.6O4wassynthesized via the hydrothermal synthesis, high-temperature calcination andpickling delithiation reactions. The intermediates and final products werecharacterized by scanning electron microscopy （SEM） and x-ray powderdiffraction (XRD). The adsorption, desorption and selective activities of theadsorbents H1.6Mn1.6O4were researched. The results showed that the adsorbents hadthe maximum adsorption capacity of46mg·g-1, and when the desorption liquid is0.5M, the desorption-rate was95%, and dissolved loss rate was low. After fiveadsorption and desorption operations, the adsorbents adsorption capacity was higherthan35mg·g-1. In selective experiments with other ions on Li+adsorption, theadsorbents showed good selectivity for Li+.Based on Li1.6Mn1.6O4, poly(vinyl chloride)(PVC) and poly(vinylidenefluoride)(PVDF) separately were used separately to prepare H1.6Mn1.6O4-PVC andH1.6Mn1.6O4-PVDF flat hybrid membranes for recovering lithium fromlithium-containing waters by a solvent exchange method, the membrane structureand properties were characterized. As for H1.6Mn1.6O4-PVC hybrid membrane, whentreated with lithium solutions for6h the maximum adsorption capacity reached29mg·g-1, and with an HCl solution for1h can reach the balance of desorption. While for H1.6Mn1.6O4-PVDF hybrid membrane, the adsorption capacity was41mg·g-1after the adsorption process conducted for12h, and desorption process can reachthe balance for2h.95%lithium was extracted for all the membrane, and they alsohad the same selectively on Li+with H1.6Mn1.6O4in competitive adsorption withNa+、K+、Mg2+. Also when used for the fifth time the membrane showed goodproperty in adsorption capacity.