Processes for recovering lithium values from lithium-containing brines

A process for producing an aqueous lithium-containing solution from a source of dissolved lithium that also contains at least Na+, Ca2+, and Mg2+ in solution, which process comprises:

• (A) passing said source of dissolved lithium into and out of a bed of sorbent comprised of hydrated alumina intercalated with LiX, where X is an anion of a lithium salt, to thereby extract at least a portion of lithium from the source of dissolved lithium into the sorbent;
• (B) washing the bed of sorbent with a dilute solution of lithium chloride to obtain a lithium eluent solution;
• (C) subjecting the lithium eluent solution to nanofiltration to produce a lithium-containing permeate solution and a retentate solution comprising a total amount of Ca2+ and Mg2+ of at least 75% as compared to the total amount Ca2+ and Mg2+ in said source of dissolved lithium and wherein the permeate solution comprises a total content of dissolved Ca2+ and Mg2+ that is 25% or less as compared to said lithium eluent solution;
• and
• (D) subjecting said permeate solution to forward osmosis through a plurality of successive or parallel semi-permeable forward osmosis membranes in units that further reduce the water content of said permeate solution and thereby further increase the lithium concentration of the permeate solution so that it is in the range of about 13,000 to about 25,000 ppm of dissolved lithium.