Abstract: Producing high purity lithium solution from a lithium source containing dissolved Na+, Ca2+, and Mg2+, by: passing the source into and out of a bed of sorbent composed of hydrated alumina intercalated with LiX, preferably LiCl, to extract lithium from the lithium source into the sorbent; washing the bed of sorbent with dilute aqueous LiCl to remove lithium from the sorbent to obtain a lithium eluent of increased Li+ concentration; subjecting this eluent to nanofiltration to produce a lithium permeate from which Ca2+, Mg2+, and other nanofilterable components are concurrently removed, yielding a permeate solution with 25% or less, and a retentate solution with 75% or more Ca2+ and Mg2+, as compared to the eluent from washing; and subjecting the permeate solution to a particular forward osmosis yielding a solution having 13,000-25,000 ppm dissolved lithium. Specified optional steps and new features can be used to increase lithium concentrations and purity.

Abstract: A process for removing at least Ca2+ and Mg2+ from a lithium-containing brine. The process comprises (i) providing an aqueous lithium-containing brine feed comprising dissolved Ca2+ and Mg2+ impurities in a weight ratio of Li+:Ca2+ of about 4:1 to 50:1 wt/wt and in a weight ratio of Li+:Mg2+ of about 4:1 to 50:1; (ii) subjecting said brine feed to nanofiltration to produce a lithium-containing permeate from which Ca2+ and Mg2+ components are being removed concurrently; and (iii) conducting the nanofiltration so that a separation occurs and a retentate solution is formed with a total amount of Ca2+ and Mg2+ of at least 75% of the total amount of Ca2+ and Mg2+ in the original aqueous lithium-containing brine feed and forming an aqueous lithium-containing permeate solution in which the total content of dissolved Ca2+ and Mg2+ is decreased to 25% or less as compared to the original aqueous lithium-containing brine feed.

Abstract: Producing high purity lithium solution from a lithium source containing dissolved Na+, Ca2+, and Mg2+, by: passing the source into and out of a bed of sorbent composed of hydrated alumina intercalated with LiX, preferably LiCl, to extract lithium from the lithium source into the sorbent; washing the bed of sorbent with dilute aqueous LiCl to remove lithium from the sorbent to obtain a lithium eluent of increased Li+ concentration; subjecting this eluent to nanofiltration to produce a lithium permeate from which Ca2+, Mg2+, and other nanofilterable components are concurrently removed, yielding a permeate solution with 25% or less, and a retentate solution with 75% or more Ca2+ and Mg2+, as compared to the eluent from washing; and subjecting the permeate solution to a particular forward osmosis yielding a solution having 13,000-25,000 ppm dissolved lithium. Specified optional steps and new features can be used to increase lithium concentrations and purity.