Processes for recovering lithium values from lithium-containing brines

A process for producing a high purity aqueous lithium-containing solution from a source of dissolved lithium, which process comprises:

• a. a source brine containing at least 1 mg Li/kg brine;
• b. treating the source brine in one or more pretreatment steps comprising;
• i. concentration of Li in the source brine or evaporation of water in the source brine comprising one or more of fractional freezing, membrane techniques, thermal evaporation, vacuum evaporation, cooling tower evaporation including forced or induced draft, solar evaporation, forced air evaporation or passive evaporation;
• and
• ii. adjustment of a temperature of the source brine to less than 110 degrees C.;
• c. processing the treated brine in a lithium adsorption step;
• d. after the adsorption step, desorbing the adsorbed lithium in a desorption step;
• e. after the desorption step and prior to an enrichment step, treating the desorption effluent to remove impurities, wherein the treatment step creates a brine of less than about 100 ppm of residual H2S or other sulfides;
• and
• f. after the treatment step, treating the desorption effluent in the enrichment step comprising membrane filtration and ion exchange resin;
• and
• g. regenerating the ion exchange resin, wherein solutions used to regenerate the ion exchange resin are recycled to adjust pH or osmotic strength elsewhere in the enrichment step or the adsorption step or the desorption step or in lithium depleted brine.