The present invention relates to a method for recovering a rare metal salt, the method including: an acid treatment step of obtaining a rare metal-containing acidic aqueous solution by bringing a material including a monovalent rare metal and a polyvalent rare metal into contact with an acidic aqueous solution; a separation step of obtaining permeated water including the monovalent rare metal and non-permeated water including the polyvalent rare metal from the rare metal-containing acidic aqueous solution by using a nanofiltration membrane satisfying the condition (1); and a concentration step of obtaining non-permeated water having a higher concentration of the monovalent rare metal and permeated water having a lower concentration of the monovalent rare metal than that of the permeated water in the separation step, by using a reverse osmosis membrane.

A lithium adsorbent includes an aluminum-based adsorbing material, a binder, and a wetting and dispersing agent. The binder includes at least one of a vinylidene fluoride-chlorotrifluoroethylene (VDF-CTFE) copolymer and a fluoroolefin-vinyl ether copolymer. The wetting and dispersing agent includes one or more of polyethylene glycol, sodium polyacrylate, polyvinyl alcohol, and formaldehyde condensate.

A lithium adsorbent includes an aluminum-based adsorbing material, a binder, and a wetting and dispersing agent. The binder includes at least one of a vinylidene fluoride-chlorotrifluoroethylene (VDF-CTFE) copolymer and a fluoroolefin-vinyl ether copolymer. The wetting and dispersing agent includes one or more of polyethylene glycol, sodium polyacrylate, polyvinyl alcohol, and formaldehyde condensate.

Systems and methods using solar evaporation to preconcentrate lithium containing brines to at or near lithium saturation, followed by a separation processes to separate lithium from impurities. A separated impurity stream is recycled to a point in the evaporation sequence where conditions are favorable for their precipitation and removal or disposed in a separate evaporation pond or reinjected underground, while a lower impurity stream is transferred to one or more of the removal location, to a subsequent pond in the sequence, or to a lithium plant or concentration facility. Further concentration of lithium by evaporation can then take place because impurities are removed thus eliminating lithium losses due to co-precipitation and achieving significantly higher concentrations of lithium.

Systems and methods using solar evaporation to preconcentrate lithium containing brines to at or near lithium saturation, followed by a separation processes to separate lithium from impurities. A separated impurity stream is recycled to a point in the evaporation sequence where conditions are favorable for their precipitation and removal or disposed in a separate evaporation pond or reinjected underground, while a lower impurity stream is transferred to one or more of the removal location, to a subsequent pond in the sequence, or to a lithium plant or concentration facility. Further concentration of lithium by evaporation can then take place because impurities are removed thus eliminating lithium losses due to co-precipitation and achieving significantly higher concentrations of lithium.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

This invention relates to a method for the preparation of lithium carbonate from lithium chloride containing brines. The method can include a silica removal step, capturing lithium chloride, recovering lithium chloride, supplying lithium chloride to an electrochemical cell and producing lithium hydroxide, contacting the lithium hydroxide with carbon dioxide to produce lithium carbonate.

Pyrometallurgic process for obtaining lithium compounds and intermediates, the process being characterized by comprising the steps of a) contacting lithium aluminosilicate particles with at least a fluorine solid compound, b) heating until a temperature of 25 to 900° C. obtaining a solid mixture and c) carrying out at least a leaching process of the mixture in step b).

Pyrometallurgic process for obtaining lithium compounds and intermediates, the process being characterized by comprising the steps of a) contacting lithium aluminosilicate particles with at least a fluorine solid compound, b) heating until a temperature of 25 to 900° C. obtaining a solid mixture and c) carrying out at least a leaching process of the mixture in step b).

Processes are disclosed for the preparation of granular sorbent, useful to recover lithium values from brine. The process comprises reacting a granular aluminum hydroxide with an aqueous solution containing lithium salt and alkali hydroxide, optionally in the presence of alkali chloride. The granular aluminum hydroxide can be a compressed aluminum hydroxide having an average particle size of at least 300 microns. The granular sorbent obtained by the method and its use to recover lithium values from brine are disclosed.