A method for preparing lithium concentrate from natural lithium-bearing brines was developed. The brine is first subjected to purification from the suspended solids, then filtered through a static layer of a granulated sorbent based on LiCl.2Al(OH).sub.3.mH.sub.2O, where m=3-5, to obtain a primary lithium concentrate. The process is carried out in sorption-desorption units consisting of 4 columns, two of which are in the process of sorption of lithium chloride from the brine, one column is in the process of washing the sorbent saturated with lithium chloride from the brine, and one column is in the process of lithium chloride desorption. The primary lithium concentrate is converted to a secondary lithium concentrate by concentration in evaporative pools or reverse osmotic concentration-desalination. The secondary lithium concentrate is used for further production of lithium chloride or lithium carbonate.

This invention provides a membrane electrode material and its preparation method, as well as the application of the material into lithium extraction by adsorption-electrochemical coupling method. The membrane electrode material is described as MnO@C. The preparation steps are as follows: LiMn.sub.2O.sub.4 is firstly obtained by calcining lithium carbonate and manganese carbonate, which is then dispersed in hydrochloric acid solution. After stirring and separating, the solid products are dried to obtain λ-MnO.sub.2. The λMnO.sub.2 is added to the raw material of Mn-MOF-74, and then the Mn-MOF-74 coated λ-MnO.sub.2 can be obtained by hydrothermal reaction. By further calcining Mn-MOF-74 coated λ-MnO.sub.2 in nitrogen atmosphere, the membrane capacitor/electrode material can be obtained as MnO@C. The material is fabricated into an adsorption film electrode plate and assembled into an adsorption-electrochemical coupling lithium extraction device. The pure lithium solution can be obtained in the recovery pool through the combined lithium extraction and lithium recovery process. In this invention, the thickness of the carbon coating layer in the electrode material is adjustable. Adsorption-electrochemical coupling technology takes the advantages of both adsorption and electrochemical lithium intercalation, which can extract and recover lithium resources with high capacity. Thus, this invention not only achieves high-efficiency separation of lithium resources, but also opens up a new way for the extraction of lithium resources.

This invention provides a membrane electrode material and its preparation method, as well as the application of the material into lithium extraction by adsorption-electrochemical coupling method. The membrane electrode material is described as MnO@C. The preparation steps are as follows: LiMn.sub.2O.sub.4 is firstly obtained by calcining lithium carbonate and manganese carbonate, which is then dispersed in hydrochloric acid solution. After stirring and separating, the solid products are dried to obtain λ-MnO.sub.2. The λMnO.sub.2 is added to the raw material of Mn-MOF-74, and then the Mn-MOF-74 coated λ-MnO.sub.2 can be obtained by hydrothermal reaction. By further calcining Mn-MOF-74 coated λ-MnO.sub.2 in nitrogen atmosphere, the membrane capacitor/electrode material can be obtained as MnO@C. The material is fabricated into an adsorption film electrode plate and assembled into an adsorption-electrochemical coupling lithium extraction device. The pure lithium solution can be obtained in the recovery pool through the combined lithium extraction and lithium recovery process. In this invention, the thickness of the carbon coating layer in the electrode material is adjustable. Adsorption-electrochemical coupling technology takes the advantages of both adsorption and electrochemical lithium intercalation, which can extract and recover lithium resources with high capacity. Thus, this invention not only achieves high-efficiency separation of lithium resources, but also opens up a new way for the extraction of lithium resources.

Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of desirable materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. Depending on a desired proportion, or ratio, of the desired materials, raw materials are added to the solution to achieve the desired ratio of the commingled compounds for the recycled cathode material for new cells. The desired materials precipitate out of solution without extensive heating or separation of the desired materials into individual compounds or elements. The resulting active cathode material has the predetermined ratio for use in new cells, and avoids high heat typically required to separate the useful elements because the desired materials remain commingled in solution.

The installation for separating a multivalent cationic species from a solution comprising this multivalent cationic species and lithium comprises a capture device (3) having an entry (2) and an exit (4). The capture device (3) comprises, between the entry (2) and the exit (4), a microfibre product (12) with a higher affinity for multivalent cations than for monovalent cations. The installation comprises a circulation system (5) adapted to circulate the solution from the entry (2) to the exit (4) in contact with the microfiber product (21), the microfibre product (21) capturing said multivalent cationic species.

The installation for separating a multivalent cationic species from a solution comprising this multivalent cationic species and lithium comprises a capture device (3) having an entry (2) and an exit (4). The capture device (3) comprises, between the entry (2) and the exit (4), a microfibre product (12) with a higher affinity for multivalent cations than for monovalent cations. The installation comprises a circulation system (5) adapted to circulate the solution from the entry (2) to the exit (4) in contact with the microfiber product (21), the microfibre product (21) capturing said multivalent cationic species.

A method for producing a lithium iron phosphate precursor by using a retired lithium iron phosphate battery as a raw material is provided, which includes steps of: soaking a battery cell in acid, performing electrolysis to reclaim copper, oxidizing ferrous iron, precipitating iron phosphate, and precipitating lithium carbonate. After precipitation is completed, performing one-step reclaim to obtain the lithium iron phosphate precursor.

A method for producing a lithium iron phosphate precursor by using a retired lithium iron phosphate battery as a raw material is provided, which includes steps of: soaking a battery cell in acid, performing electrolysis to reclaim copper, oxidizing ferrous iron, precipitating iron phosphate, and precipitating lithium carbonate. After precipitation is completed, performing one-step reclaim to obtain the lithium iron phosphate precursor.

According to the present invention there is provided a method for the extraction of lithium from one or more lithium-containing ores such as spodumene, the inventive method comprising the steps of: milling said ore/s to a predetermined average particle size; optionally calcining the milled ore; further optionally performing a secondary milling step; providing an aqueous suspension of the one or more lithium-containing ores at a predetermined solids concentration; subjecting the one or more lithium-containing ores to an aqueous extraction medium defined by a predetermined partial pressure of CO.sub.2, a predetermined extraction temperature, over a predetermined time; and obtaining technical grade lithium carbonate/lithium bicarbonate therefrom. Optional concentration and/or precipitation/purification steps may follow.

The disclosure provides seven integrated methods for the chemical sequestration of carbon dioxide (CO.sub.2), nitric oxide (NO), nitrogen dioxide (NO.sub.2) (collectively NO.sub.x, where x=1, 2) and sulfur dioxide (SO.sub.2) using closed loop technology. The methods recycle process reagents and mass balance consumable reagents that can be made using electrochemical separation of sodium chloride (NaCl) or potassium chloride (KCl). The technology applies to marine and terrestrial exhaust gas sources for CO.sub.2, NOx and SO.sub.2. The integrated technology combines compatible and green processes that capture and/or convert CO.sub.2, NOx and SO.sub.2 into compounds that enhance the environment, many with commercial value.