The invention relates to a process for the preparation of high-purity lithium carbonate from brines.

The invention relates to a process for the preparation of high-purity lithium carbonate from brines.

A process for the recovery of lithium from lithium bearing mica rich minerals, the process comprising passing an ore containing one or more lithium bearing mica rich minerals to at least one pre-treatment step, passing the pre-treated ore to an acid leach step thereby producing a pregnant leach solution, subjecting the pregnant leach solution to a series of process steps in which one or more impurity metals are removed, and recovering lithium as a lithium containing salt product.

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 invention relates to a process for producing a lithium-containing solution from a lithium-containing raw-material solution, by: a) precipitating a first part of magnesium and calcium from the lithium-containing raw-material solution, b) extracting a second part of calcium and magnesium from the lithium-containing solution by liquid-liquid extraction, a resultant product being a lithium-containing solution. The invention also relates to equipment for producing a lithium-containing solution from a lithium-containing raw-material solution, including a precipitation unit to remove a first part of magnesium and calcium and an extraction unit to receive the lithium-containing raw-material solution and to remove therefrom a second part of calcium and magnesium by liquid-liquid extraction, and control unit to control the operation of the precipitation unit.

The invention relates to a process for producing a lithium-containing solution from a lithium-containing raw-material solution, by: a) precipitating a first part of magnesium and calcium from the lithium-containing raw-material solution, b) extracting a second part of calcium and magnesium from the lithium-containing solution by liquid-liquid extraction, a resultant product being a lithium-containing solution. The invention also relates to equipment for producing a lithium-containing solution from a lithium-containing raw-material solution, including a precipitation unit to remove a first part of magnesium and calcium and an extraction unit to receive the lithium-containing raw-material solution and to remove therefrom a second part of calcium and magnesium by liquid-liquid extraction, and control unit to control the operation of the precipitation unit.

A method for processing positive electrode active material waste of lithium ion secondary batteries, the waste containing cobalt, nickel, manganese and lithium, the method including: a carbon mixing step of mixing the positive electrode active material waste in the form of powder with carbon to obtain a mixture having a ratio of a mass of carbon to a total mass of the positive electrode active material waste and the carbon of from 10% to 30%; a roasting step of roasting the mixture at a temperature of from 600° C. to 800° C. to obtain roasted powder; a dissolution step including a first dissolution process of dissolving lithium in the roasted powder in water or a lithium-containing solution, and a second dissolution process of dissolving the lithium in a residue obtained in the first dissolution process in water; and an acid leaching step of leaching a residue obtained in the lithium dissolution step with an acid.

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.

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.

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.