SORBENT REGENERATION METHOD FOR DIRECT LITHIUM EXTRACTION

Claims

This disclosure relates generally to the direct lithium extraction (DLE) of lithium from brines. More specifically, it relates to methods for regenerating layered double hydroxide (LDH) sorbents and methods for their use in DLE. This disclosure indicates that escalating anionic displacement (EAD), divalent-supported anionic displacement (DSAD), and / or modified brine DSAD (MB-DSAD) can be used to override empirically derived anion incorporation hierarchies and thereby reduce, avoid, or eliminate contamination in LDH sorbents. This disclosure also explains that lithium elution can be suppressed by solutions comprising high concentrations of anions and cations.As stated in this disclosure, this finding can be leveraged in combination with EAD, DSAD, and / or MB-DSAD to regenerate LDH sorbents in situ. In selected methods described herein, DLE adsorption-elution cycles are supplemented with regenerative washes to restore and / or maintain the lithium uptake capacity and / or lithium elution capacity of an LDH sorbent.