Preparation of PVC-LMZO membrane and its lithium adsorption performance from brine

Abstract

The forming technology of lithium ion sieves is of great significance for their industrial production and application in brine. A PVC-LMZO lithium ion sieve precursor membrane was prepared by blending the zirconium-coated lithium ion sieve precursor LMZO with PVC, PMMA and PVPk30. The adsorption and cyclic performance of the PVC-LMZO membrane obtained after treatment with HCl were studied. The results showed that the optimal condition for membrane preparation is to add 10 wt% PVC, 20 wt% LMZO, 6 wt% PMMA and 2 wt% PVPk30. After treatment with 0.1 mol·L−1 HCl for 2 h, the lithium desorption reached equilibrium, and the manganese loss rate was approximately 0.332 %. After 15 cycles of adsorption and desorption in brine, the Li+ adsorption capacity was lost by only 5.8 % (from 18.33 mg/g to 17.27 mg/g). The PVC-LMZO membrane had high selectivity for Li+ in brine containing a variety of complex ions such as K+, Ca2+, Na+ and Mg2+. The PVC-LMZO membrane has a stable structure and excellent recycling performance, which is conducive to its industrial application. The PVC-LMZO membrane accords with the Langmuir adsorption isotherm model and pseudo-second-order kinetics model, indicating a monolayer chemisorption. The PVC-LMZO membrane has great development potential for extracting lithium from liquid lithium resources such as salt lake brine.