Producing high purity lithium solution from a source brine containing at least 1 mg Li/kg brine, preferably 10 mg/kg, more preferably 25 mg Li/kg brine; treating the source brine, if necessary in pretreatment steps; processing the treated brine in a lithium adsorption step; after the adsorption step, desorbing the adsorbed lithium in a desorption step; after the desorption step, treating the desorption effluent in an enrichment step. Specified optional steps and new features can be used to increase lithium concentrations and purity.

Disclosed herein are electro-dialytic crystallizers and methods of use thereof. For example, described herein are electro-dialytic crystallizer systems comprising an electro-dialysis module and a crystallizer module in liquid communication with the electrodialysis module. The electrodialysis module is configured to receive an aqueous feedwater solution and form a diluate stream and a brine stream, the aqueous feedwater solution comprising an ionic component, the diluate stream having a lower concentration of the ionic component relative to the aqueous feedwater solution, and the brine stream having a higher concentration of the ionic component relative to the aqueous feedwater solution. The crystallizer module is configured to receive the brine stream and form crystals comprising the ionic component and a supernatant. Also disclosed herein are methods of use of any of the systems disclosed herein, for example using the system to treat the aqueous feedwater solution.

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