System and method for extraction of lithium, cobalt and aluminium from active material of lithium-ion battery

Abstract

The various embodiments of the present invention provide a system and method for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery. The method involves extraction of materials from spent battery and black mass at specified temperatures to prevent melting of aluminium, followed by carbothermal reduction to convert lithium compounds into lithium carbonate. Water leaching is then used to extract lithium carbonate. The remaining material is subjected to hydrogen roasting to selectively reduce cobalt and nickel oxides to base metal, which are subsequently separated using magnetic and density separation techniques. This method offers a cost-effective, energy-efficient, and environmentally friendly solution for recycling lithium-ion batteries, optimizing metal recovery while handling high levels of contamination.

Description

SYSTEM AND METHOD FOR EXTRACTION OF LITHIUM, COBALT AND ALUMINIUM FROM ACTIVE MATERIAL OF LITHIUM-ION BATTERYCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims the priority of the Indian Provisional Patent Application filed on 2ndof September 2024, with the number 202441066210 and titled, “SYSTEM AND METHOD FOR EXTRACTION OF LITHIUM, COBALT AND ALUMINIUM FROM ACTIVE MATERIAL OF LITHIUM-ION BATTERY”, the contents of which are incorporated herein by the way of reference.

[0002] The present invention is generally related to recycling of lithium ion batteries. The present invention is particularly related to extraction technology of valuable metals from lithium ion battery. The present invention is more particularly related to a system and a method for extraction of Lithium, Cobalt and Aluminium from active materials of lithium-ion battery.

[0003] The Lithium-ion batteries are pivotal to modern technology, utilized in a vast array of electronic devices and electric vehicles. The recycling of these batteries, particularly the extraction of valuable metals like lithium, is crucial for sustainability and resource conservation. Current methods for extracting lithium primarily fall into two categories: hydrometallurgy and pyrometallurgy. Hydrometallurgy typically involves acid leaching and solvent extraction, which can be environmentally damaging and costly due to the use of harsh chemicals and the need for extensive safety measures. Pyrometallurgy, on the other hand, involves high-temperature processes such as smelting in an Electric Arc Furnace, allowing heavy metals to settle and light metals to form slag.

[0004] Both existing methods face significant challenges, especially when dealing with high levels of contamination by Aluminium and Copper. Hydrometallurgy processes are often costly and environmentally unfriendly due to the use of strong acids and solvents. Pyrometallurgy methods require high temperatures, which not only increases energy consumption but also leads to the formation of undesirable compounds, such as lithium aluminium oxide, and agglomeration of aluminium with other particles, complicating the separation process.

[0005] Hence, there exists a need for a system and a method for extraction of Lithium, Cobalt and Aluminium from active materials of lithium-ion battery, that simplifies the extraction of valuable metals, reducing both the environmental impact and the cost of recovery.

[0006] The abovementioned shortcomings, disadvantages and problems are addressed herein, which will be understood by reading and studying the following specification.OBJECT OF THE INVENTION

[0007] The primary object of the present invention is to provide a method for extracting Lithium, Cobalt, and Nickel from lithium-ion battery materials.

[0008] Another object of the present invention is to efficiently handle and process active material of Lithium ion battery contaminated with Aluminium Copper and other contaminations.

[0009] Yet another object of the present invention is to use a combination of carbothermal reduction and hydrogen roasting for metal extraction.

[0010] Yet another object of the present invention is to lower the operational and start-up costs compared to the existing lithium extraction methods.

[0011] Yet another object of the present invention is to reduce the environmental impact of lithium extraction by avoiding toxic emissions and utilizing lower temperatures.

[0012] Yet another object of the present invention is to simplify the recycling process by enabling the direct extraction and purification of lithium.

[0013] Yet another object of the present invention is to enhance the overall efficiency and yield of lithium recovery from recycled batteries.

[0014] Yet another object of the present invention is to utilize by-products of the extraction process in other industrial applications, thereby minimizing waste.

[0015] Yet another object of the present invention is to develop a scalable and industrially viable process for lithium extraction.

[0016] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0017] The various embodiments of the present invention provide a system and method for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery.

[0018] According to one embodiment of the present invention, a system is provided for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery. The system comprises: a material collection unit that collects and prepares the black mass from the spent Lithium ion batteries which contains cathode and anode active material of the batteries along with contaminants including aluminium, copper, into a uniform size particles suitable for further processing; a controlled heating chamber that heats the black mass into a specific temperature range to facilitate the carbothermal reduction reaction preventing the formation of aluminium agglomerates and copper from sintering with other particles inside the mix; a carbothermal reduction module that carries out carbothermal reduction reaction to convert lithium compounds in the black mass into lithium carbonate; a leaching and filtration module that extracts lithium carbonate from the reaction mixture, ensuring the purity of the lithium carbonate solution; a hydrogen roasting chamber that selectively reduces Cobalt and Nickel oxides into their metallic form under hydrogen atmosphere; a magnetic separation unit that separates magnetic metal particles including cobalt, nickel metal from non-magnetic materials using magnetic separators; a density separation and grinding unit that further refines the separation of metal powders including nickel particles based on their density and grinds them into desired particle size; a purification and collection unit that purifies the lithium carbonate by removing any remaining impurities, and also collects the final metal powders of cobalt and nickel; a quality control module that ensures that the purified lithium carbonate and other metals meets the industry standards; and a waste treatment unit wherein the gaseous by-products, produced during the reaction are scrubbed using appropriate methods to convert them into non-hazardous materials or the solid by-products are disposed according to environmental regulations and potential applications in other industries.

[0019] According to one embodiment of the present invention, a method is provided for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery. The method comprises: Preparation of reaction mixture, wherein the black mass is gathered from spent Lithium-ion batteries, that contain mostly cathode and anode active material along with contaminants including Aluminium and Copper, and the mixture is crushed and ground to a uniform particle size for further processing; Controlled heating and carbo-thermal reduction wherein the mixture is heated to a temperature between 600°C and 660°C, maintaining below the melting point of aluminium, to facilitate the carbothermal reduction reaction where lithium compounds are converted into lithium carbonate; Leaching and filtration processes wherein water is added to form lithium carbonate solution from the mixture and any undissolved solids and particulate matter are filtered out; Hydrogen roasting process wherein the residual material is roasted in a hydrogen atmosphere below and above reduction temperature and partial pressure of hydrogen that selectively reduces the cobalt and nickel oxides into cobalt and nickel metal powder while Manganese is left as Manganese oxide; Magnetic separation process isolates magnetic materials from non-magnetic materials; Density separation process further isolates nickel cobalt oxide or metal powder from graphite or manganese oxide; a purification and collection process that purifies the lithium carbonate by removing any remaining impurities, and also collects the final metal powders of cobalt and nickel; a quality control process that ensures that the purified lithium carbonate and other metals meets the industry standards; and a waste treatment process wherein the gaseous by-products, produced during the reaction are scrubbed using appropriate methods and converted into non-hazardous materials, or the solid by-products are disposed according to environmental regulations and potential applications in other industries.

[0020] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating the preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

[0021] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:

[0022] illustrates a system for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery, according to one embodiment of the present invention.

[0023] illustrates a method for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery, according to one embodiment of the present invention.

[0024] Although the specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.

[0025] In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.

[0026] According to one embodiment of the present invention, a system is provided for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery. The system comprises: a material collection unit that collects and prepares the black mass from the spent Lithium ion batteries which contains cathode and anode active material of the batteries including Nickel Manganese Cobalt oxide (NMC), Lithium Cobalt Oxide (LCO) and Lithium Manganese Oxide (LMO) and graphite along with contaminants including aluminium, copper, into a uniform size particles suitable for further processing, using a plurality of conveyors, crushers and sorting modules; a controlled heating chamber that comprises a plurality of furnaces, along with a plurality of sensors and controllers, that heats the black mass into a specific temperature range to facilitate the carbothermal reduction reaction preventing the melting of aluminium and formation of agglomerates, and also prevents copper from sintering with other particles inside the mix; a carbothermal reduction module that carries out carbothermal reduction reaction to convert lithium compounds in the black mass into lithium carbonate; a leaching and filtration module that comprises a plurality of leaching tanks followed by filtration systems to extract lithium carbonate from the reaction mixture, ensuring the purity of the lithium carbonate solution before passing the solution to the hydrogen roasting chamber; a hydrogen roasting chamber that selectively reduces Cobalt and Nickel oxides into their metallic form under hydrogen atmosphere; a magnetic separation unit that separates magnetic metal particles from non-magnetic materials using magnetic separators; a density separation and grinding unit that further refines the separation of metal powders including nickel cobalt particles based on density and grinds them into desired particle size; a purification and collection unit that purifies the lithium carbonate by removing any remaining impurities, and also collects the final metal powders of cobalt and nickel; a quality control module that ensures that the purified lithium carbonate and other metals meets the industry standards; and a waste treatment unit wherein the gaseous by-products, produced during the reaction are scrubbed using appropriate methods to convert them into non-hazardous materials and the solid by-products are disposed according to environmental regulations and potential applications in other industries.

[0027] According to one embodiment of the present invention, a method is provided for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery. The method comprises: Preparation of reaction mixture, wherein the black mass is gathered from spent Lithium-ion batteries, that contain mostly cathode and anode active material of the batteries along with contaminants including Aluminium and Copper, and the mixture is crushed and ground to a uniform particle size for further processing; Controlled heating and carbo-thermal reduction wherein the mixture is heated to a temperature between 600°C and 660°C, maintaining below the melting point of aluminium, to facilitate the carbothermal reduction reaction where lithium compounds are converted into lithium carbonate; Leaching and filtration processes wherein water is added to form lithium carbonate solution from the mixture and any undissolved solids and particulate matter are filtered out; Hydrogen roasting wherein the residual material is roasted in a hydrogen atmosphere below the melting point of aluminium and above reduction temperature and partial pressure of hydrogen while selectively reduces the cobalt and nickel oxides into cobalt and nickel metal powder while Manganese is left as Manganese oxide; Magnetic separation process that isolates magnetic materials from non-magnetic materials; Density separation process that further isolates nickel, cobalt powder; a purification and collection process that purifies the lithium carbonate by removing any remaining impurities, and also collects the final metal powders of cobalt and nickel; a quality control process that ensures that the purified lithium carbonate and other metals meets the industry standards; and a waste treatment process wherein the gaseous by-products, produced during the reaction are scrubbed using appropriate methods to convert them into non-hazardous materials and / or the solid by-products are disposed according to environmental regulations and potential applications in other industries.

[0028] According to one embodiment of the present invention, the carbothermal reduction process primarily comprises the following reaction:

[0029]

[0030] M= Ni, Co, Mn

[0031] According to one embodiment of the present invention, the Hydrogen roasting process primarily comprises the following reaction:

[0032] According to one embodiment herein, a system is provided for extraction of lithium carbonate, cobalt and nickel from active material of lithium-ion batteries with high contamination. The system comprises a material collection unit configured to process black mass derived from spent lithium-ion batteries, a controlled heating chamber configured to heat the black mass at a temperature sufficient for carbothermal reduction while preventing aluminium melting and copper sintering, a carbothermal reduction module configured to convert lithium compounds into lithium carbonate, a leaching and filtration module configured to mix the reduced mass with water and carbon dioxide under controlled conditions to extract lithium carbonate solution, a selective nitric acid leaching unit configured to dissolve residual lithium, aluminium and copper, a hydrogen roasting chamber configured to reduce cobalt and nickel oxides to metallic powders, a magnetic separation unit configured to separate cobalt nickel metal from other residues, a density separation and grinding unit configured to isolate nickel cobalt metal / oxide powders and grind them to uniform sizes, a purification and collection unit configured to purify and collect lithium carbonate, cobalt and nickel, a quality control module configured to validate product specifications, and a waste treatment unit configured to scrub gaseous by-products and process solid residues for safe disposal or reuse.

[0033] According to one embodiment herein, the material collection unit is further configured to wash the black mass with water and subsequently add nitric acid in an amount up to five percent by weight to neutralize the pH, thereby dissolving lithium fluoride, lithium carbonate and lithium hexaphosphate salts before drying and crystallizing the separated salts from solution.

[0034] According to one embodiment herein, the controlled heating chamber is configured to maintain the black mass at temperatures in the range of six hundred to six hundred and sixty degrees Celsius, thereby facilitating carbothermal reduction without crossing the melting point of aluminium.

[0035] According to one embodiment herein, the leaching and filtration module is configured to inject carbon dioxide gas at pressures ranging from 0.1 bar to 15 bar and at temperatures between four and forty degrees Celsius, thereby achieving lithium concentration of up to ten grams per litre while ensuring that slurry pH remains above seven to prevent leaching of transition metals.

[0036] According to one embodiment herein, the selective nitric acid leaching unit is configured to dissolve residual lithium, aluminium and copper by controlled dosing of nitric acid in decreasing order of pH, and is further configured to conduct staged leaching with intermediate water changes for improved selectivity.

[0037] According to one embodiment herein, the hydrogen roasting chamber is configured to selectively reduce nickel and cobalt oxides to metallic powders under a reducing hydrogen atmosphere while manganese remains as manganese oxide.

[0038] According to one embodiment herein, the magnetic separation unit is a wet magnetic separator configured to repeatedly isolate cobalt nickel powders from non-magnetic residues.

[0039] According to one embodiment herein, the density separation and grinding unit is configured to perform repeated cycles of density-based separation and grinding to isolate nickel metal powders and reduce them to industrially acceptable particle sizes.

[0040] According to one embodiment herein, the waste treatment unit is configured to scrub gaseous effluents using chemical absorbents and to crystallize solid by-products for safe disposal or reuse in industrial applications.

[0041] According to one embodiment herein, a method is provided for extraction of lithium carbonate, cobalt and nickel from active material of lithium-ion batteries with high contamination. The method comprises preparing a reaction mixture by collecting black mass and contaminants, washing the black mass, neutralizing dissolved salts with acid, dewatering and drying the material, and crystallizing the separated salts. The method further comprises heating the material in a controlled chamber at a temperature sufficient to enable carbothermal reduction while preventing aluminium from melting and copper from sintering, and carrying out carbothermal reduction of lithium compounds into lithium carbonate under these controlled conditions. The method also comprises leaching and filtering the reduced material by mixing with water, injecting carbon dioxide under controlled temperature and pressure while maintaining slurry pH above seven, and filtering to extract lithium solution. The method further comprises subjecting the residue to selective nitric acid leaching to dissolve residual lithium, aluminium and copper, roasting the residue in a hydrogen atmosphere to selectively reduce nickel and cobalt oxides to metallic powders, separating the metallic powders using magnetic separation and density separation with grinding, purifying and collecting lithium carbonate, cobalt and nickel to industrial standards, validating the quality of the extracted products, and treating gaseous and solid by-products to render them non-hazardous or suitable for reuse.

[0042] According to one embodiment herein, preparing the reaction mixture further comprises adding nitric acid in an amount up to five percent by weight to dissolve lithium fluoride, lithium carbonate and lithium hexaphosphate salts prior to drying the material.

[0043] According to one embodiment herein, the heating and carbothermal reduction step is performed at a temperature between six hundred and six hundred and sixty degrees Celsius.

[0044] According to one embodiment herein, the carbothermal reduction step is conducted for durations between six and ten hours on industrial batches weighing up to seven hundred and twenty kilograms.

[0045] According to one embodiment herein, the leaching and filtering step includes injecting carbon dioxide at pressures between 0.1 bar and 15 bar and at temperatures between four and forty degrees Celsius, thereby achieving lithium concentration of up to ten grams per litre.

[0046] According to one embodiment herein, the selective nitric acid leaching step is performed in staged dosing with intermediate water changes to selectively dissolve residual lithium, aluminium and copper.

[0047] According to one embodiment herein, the hydrogen roasting step reduces nickel and cobalt oxides to metals while manganese remains as manganese oxide.

[0048] According to one embodiment herein, separating the metallic powders comprises repeated magnetic and density separation cycles until a desired purity and manganese content is achieved.

[0049] According to one embodiment herein, the purifying and collecting step yields lithium carbonate directly in purified form, and cobalt and nickel in metallic powder form.

[0050] According to one embodiment herein, the treating of by-products further comprises scrubbing gaseous effluents using chemical absorbents and crystallizing solid residues for safe disposal or reuse.

[0051] illustrates a system for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery, according to one embodiment of the present invention. The system comprises: material collection unit 101; controlled heating chamber 102; carbothermal reaction module 103; leaching and filtration unit 104; Hydrogen roasting chamber 105; Magnetic separation unit 106; Density separation unit 107; Purification and collection unit 108; Quality control module 109; and waste treatment unit 110.

[0052] illustrates a method for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery, according to one embodiment of the present invention. The method comprises Preparation of reaction mixture (201); Controlled heating and carbothermal reduction (202); Leaching and filtration (203); Hydrogen roasting (204); Magnetic separation of metal powders (205); Density separation of metal powders (206); purification and collection process (207); quality control process (208); and waste treatment (209).

[0053] Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the embodiments herein with modifications.ADVANTAGEOUS EFFECT OF INVENTION

[0054] The various embodiments of the present invention provide a system and method for extraction of lithium, cobalt and nickel from active materials of lithium-ion battery. The present invention provides several advantages over conventional methods. Unlike traditional hydrometallurgical and pyrometallurgical methods, this invention does not rely on harmful acids or solvents, nor does it require high-energy-consuming smelting processes. The carbothermal process at controlled temperatures reduces the environmental footprint by minimizing toxic emissions and energy consumption, promoting a more sustainable approach to lithium recycling. By eliminating the need for expensive chemicals and reducing energy requirements, the operational and startup costs are considerably lower compared to traditional methods.

[0055] The system operates at lower temperatures, specifically below the melting point of aluminium, which significantly reduces energy consumption and prevents undesirable side reactions such as the formation of lithium aluminium oxide and the agglomeration of aluminium with other particles. This temperature control ensures a more efficient and cleaner extraction process.

[0056] The combination of carbothermal reduction and hydrogen roasting approach enhances the selective reduction of cobalt and nickel oxides to their metallic forms, while manganese remains as manganese oxide, improving the purity of the extracted metals, making them more suitable for reuse in industrial applications. The use of water leaching to extract lithium carbonate directly from the mixture simplifies the process and eliminates the need for complex and costly chemical treatments. The magnetic and density separation techniques employed in this invention further ensure that the extracted metal powders are of high purity and meet desired specifications.

[0057] This extraction method is more efficient and less labor-intensive compared to traditional mechanical and chemical processes. The system design minimizes operational costs and start-up capital, making it a more economical solution for recycling lithium-ion batteries.

[0058] By avoiding the use of strong acids and high-temperature furnaces, the process reduces the environmental impact typically associated with hydrometallurgy and pyrometallurgy methods. The invention provides a sustainable and eco-friendly alternative for extracting valuable metals from battery waste.

[0059] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such as specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications. However, all such modifications are deemed to be within the scope of the claims.

Claims

A system for extraction of lithium carbonate, cobalt and nickel from active material of lithium-ion batteries, the system comprising:a material collection unit (101) configured to receive and process black mass derived from spent lithium-ion batteries, the black mass comprising cathode and anode active materials and contaminants including aluminium, copper, lithium fluoride and phosphate salts, wherein the material collection unit washes, neutralizes, dewaters and dries the black mass to a controlled moisture level, and crystallizes dissolved salts from separated liquid effluents;a controlled heating chamber (102) configured to heat the processed black mass to a temperature sufficient to facilitate carbothermal reduction while remaining below the melting point of aluminium and below the sintering point of copper, thereby preventing agglomeration and formation of undesirable compounds;a carbothermal reduction module (103) configured to convert lithium compounds in the black mass into lithium carbonate by subjecting the black mass to sustained controlled heating conditions;a leaching and filtration module (104) configured to mix the carbothermal reduced material with water under controlled slurry conditions, inject carbon dioxide gas under regulated conditions of pressure and temperature to enhance solubility of lithium while maintaining slurry pH above 7, and subsequently filter the slurry to extract lithium carbonate solution while leaving undissolved residue;a selective nitric acid leaching unit integrated with the leaching and filtration module and configured to dissolve residual lithium, aluminium and copper from the undissolved residue by controlled dosing of nitric acid in decreasing order of pH;a hydrogen roasting chamber (105) configured to treat the residue under a hydrogen atmosphere at a temperature above the reduction temperature of nickel and cobalt oxides and under a hydrogen partial pressure sufficient to selectively reduce the oxides into metallic nickel and cobalt powders;a magnetic separation unit (106) configured to isolate cobalt and other magnetic materials from non-magnetic residues using magnetic separation techniques;a density separation and grinding unit (107) configured to further separate nickel cobalt powders based on density differences and grind them to uniform industrial particle sizes;a purification and collection unit (108) configured to purify the lithium carbonate solution and collect purified lithium carbonate, cobalt metal and nickel metal powders;a quality control module (109) configured to validate the chemical composition, particle size distribution, and industry compliance of the recovered lithium carbonate, cobalt and nickel; and,a waste treatment unit (110) configured to scrub gaseous by-products to convert them into non-hazardous materials and to treat solid residues for safe disposal or industrial reuse.The system as claimed in claim 1, wherein the material collection unit (101) is configured to wash the black mass with water, add nitric acid in an amount up to 5% w / w to neutralize pH, and dissolve lithium fluoride, lithium carbonate and lithium hexaphosphate salts.The system as claimed in claim 1, wherein the controlled heating chamber (102) is configured to maintain temperatures in a range between 600°C and 660°C.The system as claimed in claim 1, wherein the leaching and filtration module (104) is configured to inject carbon dioxide at a pressure between 0.1 bar and 15 bar and at a temperature between 4°C and 40°C, thereby achieving lithium concentration of up to 10 g / L, and wherein, the selective nitric acid leaching unit is configured to perform staged acid dosing with intermediate water changes to selectively dissolve residual lithium, aluminium and copper contaminants subsequently.A method for extraction of lithium carbonate, cobalt and nickel from active material of lithium-ion batteries, the method comprising:preparing a reaction mixture by collecting black mass containing active material and contaminants, washing the black mass, neutralizing dissolved salts with acid, dewatering and drying the material, and crystallizing dissolved salts from liquid effluents;heating the material in a controlled heating chamber at a temperature sufficient to enable carbothermal reduction while preventing aluminium from melting and copper from sintering;carrying out carbothermal reduction of lithium compounds into lithium carbonate under controlled heating conditions;leaching and filtering the carbothermal reduced material by mixing with water, injecting carbon dioxide under controlled temperature and pressure, maintaining slurry pH above 7, and filtering to extract lithium carbonate solution while leaving undissolved residue;subjecting the residue to selective nitric acid leaching to dissolve residual lithium, aluminium and copper under decreasing pH conditions;roasting the residue in a hydrogen atmosphere under conditions sufficient to selectively reduce nickel and cobalt oxides into metallic powders;separating metallic powders by magnetic separation to isolate cobalt nickel metal, followed by density separation and grinding to isolate cobalt nickel metal powders;purifying and collecting lithium carbonate, cobalt metal and nickel metal to industrial standards;validating the quality of the recovered materials using a quality control process; and,treating by-products to convert gaseous emissions into non-hazardous materials and to dispose or reuse solid residues.The method as claimed in claim 5, wherein preparing the reaction mixture further comprises adding nitric acid in an amount up to 5% w / w to dissolve lithium fluoride, lithium carbonate and lithium hexaphosphate salts, and wherein, the heating and carbothermal reduction step is performed at a temperature between 600°C and 660°C.The method according to claim 5, wherein the leaching and filtering step includes injecting carbon dioxide at a pressure between 0.1 bar and 15 bar and at a temperature between 4°C and 40°C to achieve lithium concentration of up to 10 g / L, and wherein, the selective nitric acid leaching step is performed in staged dosing with intermediate water changes to selectively dissolve residual lithium, aluminium and copper.The method as claimed in claim 5, wherein the hydrogen roasting step reduces nickel and cobalt oxides to metals while manganese remains as manganese oxide, and wherein, separating the metallic powders comprises repeated magnetic and density separation cycles until a desired purity level is achieved.The method as claimed in claim 5, wherein the purifying and collecting step yields lithium carbonate directly in purified form and cobalt and nickel as metallic powders, and wherein, the treating of by-products further comprises scrubbing gaseous effluents using chemical absorbents and crystallizing solid residues for safe disposal or reuse.

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