Lithium recovery from desalination brines using specific ion-exchange resins

Description

This study evaluated the possibility of recovering lithium from brines by ion-exchange procedures. Three commercial ion-exchange resins were studied: K2629, TP207 and TP208. Different tests have been carried out with artificial solutions and real brines. In addition, tests were carried out for Li elution, regeneration of the resins and reuse of the regenerated resins. Sorption kinetics of lithium retention onto the three resins were studied and experimental data fit to the pseudo-second order kinetics model. Equilibrium sorption data were analysed by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevic approaches. Langmuir isotherm model best described the process. The order of retention capacity of the amendments was TP207 > K2629 > TP208. Recovering Li from brines was possible with ion exchange resins. In solutions containing only Li, the three resins studied had high retention yields (>95%). The presence of other ions in solution negatively affects the behavior of the three resins studied. Regarding desorption, yields obtained ranged 73.8% - 89.8%, reaching the highest (>80%) using 4 M HCl as eluting solution. Regenerated resins showed similar yields to those obtained when the resin is used for the first time.

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