The invention provides a pH response
hydrogel composite lithium adsorbent as well as a preparation method and application thereof. The method aims at solving the problems that an existing
powder lithium adsorbent is poor in fluidity and difficult to recycle and reuse in practical application. The pH response
hydrogel composite lithium adsorbent can expand under the alkaline adsorption condition required by a lithium
ion sieve and shrink under the required acidic
desorption environment, and the defect that the adsorption performance is reduced due to the fact that part of adsorption sites are covered when a traditional organic binder is formed is overcome. The preparation method of the pH response
hydrogel composite lithium adsorbent comprises the following steps: dissolving
acrylamide and
acrylic acid in water, uniformly stirring, then adding a cross-linking agent and an initiator, dissolving and uniformly stirring, then adding lithium adsorbent
powder, and ultrasonically dispersing uniformly to obtain a precursor solution; and adding a
tetramethylethylenediamine accelerant into the precursor solution, quickly and uniformly stirring, sealing, standing and curing, washing with deionized water for multiple times, and
drying to obtain the pH response hydrogel composite lithium adsorbent. The obtained adsorbent has the advantages of high
mechanical strength, simple separation and
recovery operation, good pH response cycle reversibility and the like. The hydrophilic three-dimensional
network structure expands in an alkaline lithium-containing solution, so that lithium adsorbent particles are fully exposed, and the inherent high adsorption capacity of the
powder lithium
ion sieve is exerted.