System and method for extraction of lithium from active materials

Abstract

The various embodiments of the present invention provide a system and method for extraction of lithium from active materials of lithium iron phosphate battery. The method involves extraction of materials from spent battery and heating a mixture of the battery's black mass with suitable reagents at specific temperature in a predetermined ratio, to initiate a chemical reaction that efficiently produces lithium chloride, which is then extracted through water leaching. This method eliminates the need for harmful acids and solvents, operates at lower temperatures, and directly produces lithium chloride in a form that is both pure and economically valuable. Furthermore, the process is environmentally friendly, reduces operational costs, and enhances lithium recovery rates. By-products such as calcium fluorophosphate and iron oxide are also repurposed, supporting sustainability and reducing waste. This system offers a significant improvement over traditional methods, providing a safer, more sustainable, and cost-effective solution for recycling Lithium ion batteries.

Description

SYSTEM AND METHOD FOR EXTRACTION OF LITHIUM FROM ACTIVE MATERIALSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims the priority of the Indian Provisional Patent Application filed on 2nd September 2024, with the number 202441066235 and titled, “SYSTEM AND METHOD FOR EXTRACTION OF LITHIUM FROM ACTIVE MATERIALS”, 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 for recovery of lithium. The present invention is more particularly related to a system and a method for extraction of lithium from active materials of lithium iron phosphate 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, which is energy-intensive and results in significant greenhouse gas emissions.

[0004] Both existing methods have significant drawbacks in terms of environmental impact, energy consumption, and economic viability. Additionally, they often fail to recover lithium in a form that is immediately useful, requiring further processing and refinement. This not only increases the cost but also the environmental footprint of the recycling process. Furthermore, these methods can be inefficient in selectively extracting lithium, resulting in lower recovery rates and the loss of other valuable materials.

[0005] Hence, there exists a need for a system and method for extraction of lithium from active materials of lithium iron phosphate battery, that simplifies the extraction and purification of lithium, reducing both the environmental impact and the cost of lithium 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 method for lithium extraction from lithium iron phosphate batteries.

[0008] Another object of the present invention is to eliminate the use of acids and organic solvents in the lithium extraction process.

[0009] Yet another object of the present invention is to achieve selective extraction and purification of lithium as lithium chloride directly from the battery material.

[0010] Yet another object of the present invention is to lower the operational and start-up costs compared to 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 efficacy 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 from active materials of lithium iron phosphate battery.

[0018] According to one embodiment of the present invention, the system for extraction of lithium from active materials of lithium iron phosphate battery comprises: a material collection unit that collects and prepares the black mass from the spent Lithium ion batteries, using a plurality of conveyors crushers and sorting modules; a chemical reaction / roasting chamber wherein the extracted mass from the lithium ion batteries is thoroughly combined with suitable chemical agents primarily comprising calcium chloride, in the presence of suitable catalysts at prescribed temperatures to facilitate optimal chemical reaction; a leaching and filtration module that comprises a plurality of leaching tanks followed by filtration systems to extract lithium from the reaction mixture, ensuring the purity of the lithium chloride solution before passing the solution to the crystallization stage; a crystallization and purification module designed to recover lithium chloride from the leached solution by evaporating the lithium chloride solution to crystallize lithium chloride crystals and purifying them using a plurality of purification processes;; a quality control module that ensures that the purified lithium chloride meets the industry standards; and a waste treatment unit wherein the solid and gaseous by-products, produced during the reaction 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 from active materials of lithium iron phosphate battery. The method comprises Preparation of reaction mixture, wherein the black mass is gathered from spent Lithium Iron Phosphate batteries is combined with calcium chloride in a predetermined stoichiometric ratio; Heating the mixture to ensure the complete reaction of the components; Chemical Reaction Process wherein the mixture reacts with the reagents in the presence of suitable catalysts, at optimum temperature to extract primarily Lithium chloride which is water soluble; Cooling and Separation wherein the reaction / roasting chamber is cooled and the solid by products, including Calcium fluorophosphate and iron oxide are separated; Leaching processes wherein water is added to dissolve the Lithium chloride solution and any undissolved solids and particulate matter are filtered out; Crystallization process wherein the lithium chloride solution is heated to induce crystallization of lithium chloride and is separated from the solution using a plurality of techniques including filtration and centrifugation; purification process wherein the lithium chloride is purified using a plurality of methods including recrystallization and ion exchange to achieve the desired purity levels for a plurality of applications including battery manufacturing; quality control process wherein quality assurance tests are conducted on the purified lithium chloride to ensure that it meets the industry standards; and waste treatment process wherein the solid and gaseous 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 from active materials of lithium iron phosphate battery, according to one embodiment of the present invention.

[0023] illustrates a method for extraction of lithium from active materials of lithium iron phosphate battery, according to one embodiment of the present invention, 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] The various embodiments of the present invention provide a system and method for extraction of lithium from active materials of lithium iron phosphate battery.

[0027] According to one embodiment of the present invention, the system for extraction of lithium from active materials of lithium iron phosphate battery comprises: a material collection unit that collects and prepares the black mass from the spent Lithium ion batteries, using a plurality of conveyors crushers and sorting modules; a chemical reaction chamber wherein the extracted mass from the lithium ion batteries is thoroughly combined with suitable agents primarily comprising calcium chloride, in the presence of suitable catalysts at prescribed temperatures to facilitate optimal chemical reaction; a leaching and filtration module that comprises a plurality of leaching tanks followed by filtration systems to extract lithium from the reaction mixture, ensuring the purity of the lithium chloride solution before passing the solution to the crystallization stage; a crystallization and purification module designed to recover lithium chloride from the leached solution by cooling the lithium chloride solution to precipitate or crystallize lithium chloride crystals and purifying them using a plurality of purification processes including recrystallization, ensuring optimum purity levels suitable for various applications; a quality control module that ensures that the purified lithium chloride 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.

[0028] According to one embodiment of the present invention, a method is provided for extraction of lithium from active materials of lithium iron phosphate battery. The method comprises Preparation of reaction mixture, wherein the black mass is gathered from spent Lithium Iron Phosphate batteries, that contain mostly cathode and anode active material of the batteries i.e. Lithium Iron Phosphate and graphite along with contamination like Aluminium, Copper, Lithium Fluoride, and is combined with calcium chloride in a predetermined stoichiometric ratio; Heating the mixture by placing the mixture in a reaction / roasting chamber capable of withstanding high temperatures and gradually increasing the temperature of the chamber to reach and maintain a temperature above the reaction point of calcium chloride with lithium iron phosphate, to ensure the complete reaction of the components; Chemical Reaction Process wherein the mixture reacts with the reagents in the presence of suitable catalysts, at optimum temperature to obtain primarily Lithium chloride which is water soluble; Cooling and Separation wherein the reaction chamber is cooled and the solid by products, including Calcium fluorophosphate and iron oxide are separated; Leaching processes wherein water is added to dissolve the Lithium chloride solution and any undissolved solids and particulate matter are filtered out; Crystallization process wherein the lithium chloride solution is heated to induce crystallization of lithium chloride and is separated from the solution using a plurality of techniques including filtration and centrifugation; purification process wherein the lithium chloride is purified using a plurality of methods including recrystallization to achieve the desired purity levels for a plurality of applications including battery manufacturing; quality control process wherein quality assurance tests are conducted on the purified lithium chloride to ensure that it meets the industry standards; and waste treatment process wherein the gaseous by-products, including chlorine gas, 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.

[0029] According to one embodiment of the present invention, the Chemical Reaction Process primarily comprises the following reaction:

[0030] or

[0031]

[0032] According to one embodiment herein, a system for extraction of lithium from active material of a lithium iron phosphate battery comprises a material collection unit (101) configured to receive black mass derived from spent lithium iron phosphate batteries, the black mass comprising lithium iron phosphate, graphite, and contaminant materials, and to prepare the black mass in powdered form for further processing; a chemical reaction chamber (102) configured to receive the black mass and to react the black mass with calcium chloride in a predetermined stoichiometric ratio under controlled heating conditions, wherein the reaction / roasting chamber is adapted to sustain elevated temperatures to enable conversion of lithium compounds into lithium chloride, while producing solid and gaseous by-products; a leaching and filtration module (103) fluidly connected to the chemical reaction chamber and configured to dissolve lithium chloride formed during the reaction into water, to separate undissolved solids, and to filter impurities from the lithium chloride solution; a crystallization and purification module (104) configured to recover lithium chloride crystals from the leached solution by crystallization, evaporation, or recrystallization processes, and to further purify the lithium chloride crystals using purification techniques; a quality control module (105) configured to analyze the crystallized lithium chloride and ensure compliance with industrial standards of purity; and a waste treatment unit (106) configured to collect and treat gaseous and solid by-products, wherein the waste treatment unit is adapted to scrub, neutralize, and optionally repurpose the by-products for industrial use.

[0033] According to one embodiment herein, the material collection unit (101) is configured to prepare the black mass in powdered form.

[0034] According to one embodiment herein, the chemical reaction / roasting chamber (102) is a sealed retort fabricated from corrosion-resistant material, and is equipped with an exhaust outlet connected to a chlorine scrubbing assembly.

[0035] According to one embodiment herein, the chemical reaction chamber (102) is configured to maintain a temperature of at least 400 °C to ensure completion of the reaction.

[0036] According to one embodiment herein, the chemical reaction chamber (102) is configured to maintain the reaction conditions for a preset duration to facilitate conversion of lithium compounds.

[0037] According to one embodiment herein, the leaching and filtration module (103) is configured to mix the reacted mass with water in a solid-to-liquid ratio of at least 1:0.5 to employ agitation to dissolve lithium chloride selectively.

[0038] According to one embodiment herein, the crystallization and purification module (104) is configured to heat the lithium chloride solution to a temperature of at least 150 °C to convert ferric chloride impurities into insoluble ferric oxide before crystallization of lithium chloride.

[0039] According to one embodiment herein, the waste treatment unit (106) is configured to scrub chlorine gas using wet chemical scrubbers and to dispose or repurpose solid by-products including calcium fluorophosphate as fertilizer and iron oxide as an industrial additive.

[0040] According to one embodiment herein, a method for extraction of lithium from active material of a lithium iron phosphate battery comprises the steps of preparing a reaction mixture by combining black mass obtained from spent lithium iron phosphate batteries with calcium chloride in a predetermined stoichiometric ratio; heating the reaction mixture in a chemical reaction chamber under controlled temperature conditions to initiate and complete a reaction that converts lithium compounds in the black mass into lithium chloride, while generating by-products; cooling the reaction mixture and separating the solid by-products from the reacted mass; leaching the reacted mass by dissolving the lithium chloride into water and filtering undissolved solids to obtain a lithium chloride solution; crystallizing and purifying lithium chloride from the solution by evaporation, recrystallization, roasting, techniques to achieve the desired purity level; performing quality control testing on the purified lithium chloride to ensure conformity to industrial standards; and treating waste by-products, including scrubbing gaseous emissions and separating solid by-products for disposal or reuse in industrial applications.

[0041] According to one embodiment herein, the step of preparing the reaction mixture comprises reducing the black mass into powdered form and thoroughly mixing the powder with calcium chloride.

[0042] According to one embodiment herein, the step of heating comprises maintaining the reaction chamber at a temperature of at least 400 °C to ensure complete reaction.

[0043] According to one embodiment herein, the step of heating further comprises maintaining the reaction mixture under elevated temperature for a preset duration.

[0044] According to one embodiment herein, the step of cooling and separating comprises collecting calcium fluorophosphate and iron oxide residues for potential use as fertilizers or industrial additives.

[0045] According to one embodiment herein, the leaching step comprises mixing the reacted mass with water at a solid-to-liquid ratio of at least 1:0.5 under agitation and filtering out insoluble particles.

[0046] According to one embodiment herein, the crystallization using evaporation and purification step further comprises heating the lithium chloride crystals to at least a temperature of 150 °C to convert ferric chloride impurities into ferric oxide prior to recrystallization of lithium chloride.

[0047] According to one embodiment herein, the purification step comprises recrystallization techniques.

[0048] According to one embodiment herein, the step of waste treatment comprises scrubbing chlorine gas released during the reaction using wet chemical scrubbers and collecting iron oxide residues for reuse.

[0049] illustrates a system for extraction of lithium from active materials of lithium iron phosphate battery, according to one embodiment of the present invention. The system comprises: material collection unit 101; chemical reaction chamber 102; leaching and filtration module 103; crystallization and purification module 104; quality control module 105; and waste treatment unit 106.

[0050] illustrates a method for extraction of lithium from active materials of lithium iron phosphate battery, according to one embodiment of the present invention. The method comprises Preparation of reaction mixture (201); Heating reaction mixture (202); Chemical Reaction Process (203); Cooling and Separation (204); Leaching processes (205); Crystallization process (206); purification process (207); quality control process (208); and waste treatment (209).

[0051] 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 EFFECTS OF INVENTION

[0052] The various embodiments of the present invention provide a system and method for extraction of lithium from active materials of lithium iron phosphate 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 use of calcium chloride and 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.

[0053] The present invention selectively extracts lithium as lithium chloride, which can be easily purified and crystallized thereby improving the overall recovery rates compared to existing methods that may lose lithium in complex slags or mixed metal outputs. The method allows for the direct application of by-products, such as calcium fluorophosphate and iron oxide, in various industrial fields, thereby reducing waste and adding value to the process. The system is scalable and flexible to adapt to various operational sizes and also integrate with existing facilities.

[0054] 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 from active material of a lithium iron phosphate battery, the system comprising:a material collection unit (101) configured to receive black mass derived from spent lithium iron phosphate batteries, the black mass comprising lithium iron phosphate, graphite, and contaminant materials, and to prepare the black mass in powdered form for further processing;a chemical reaction / roasting chamber (102) configured to receive the black mass and to react the black mass with calcium chloride in a predetermined stoichiometric ratio under controlled heating conditions, wherein the reaction chamber is adapted to sustain elevated temperatures to enable conversion of lithium compounds into lithium chloride, while producing solid and gaseous by-products;a leaching and filtration module (103) fluidly connected to the chemical reaction / roasting chamber and configured to dissolve lithium chloride formed during the reaction into water, to separate undissolved solids, and to filter impurities from the lithium chloride solution;a crystallization and purification module (104) configured to recover lithium chloride crystals from the leached solution by crystallization, evaporation, or recrystallization processes, and to further purify the lithium chloride crystals using purification techniques;a quality control module (105) configured to analyze the crystallized lithium chloride and ensure compliance with industrial standards of purity; and,a waste treatment unit (106) configured to collect and treat gaseous and solid by-products, wherein the waste treatment unit is adapted to scrub, neutralize, and optionally repurpose the by-products for industrial use, and wherein, wherein the waste treatment unit (106) is configured to scrub chlorine gas using wet chemical scrubbers and to dispose or repurpose solid by-products including calcium fluorophosphate as fertilizer and iron oxide as an industrial additive.The system as claimed in claim 1, wherein the material collection unit (101) is configured to prepare the black mass in powdered form.The system as claimed in claim 1, wherein the chemical reaction chamber (102) is a sealed retort fabricated from corrosion-resistant steel alloys, and is equipped with an exhaust outlet connected to a chlorine scrubbing assembly, and wherein, the chemical reaction chamber (102) is configured to maintain a temperature of at least 400 °C to ensure completion of the reaction, and wherein, the chemical reaction / roasting chamber (102) is configured to maintain the reaction conditions for a preset duration to facilitate conversion of lithium compounds.The system as claimed in claim 1, wherein the leaching and filtration module (103) is configured to mix the reacted mass with water in a solid-to-liquid ratio of at least 1:0.5 to employ agitation to dissolve lithium chloride selectively.The system as claimed in claim 1, wherein the crystallization and purification module (104) is configured to produce lithium chloride crystals using evaporation and heat the lithium chloride crystals to a temperature of at least 150 °C to convert ferric chloride impurities into insoluble iron oxide before recrystallization of lithium chloride.A method for extraction of lithium from active material of a lithium iron phosphate battery, the method comprising:preparing a reaction mixture by combining black mass obtained from spent lithium iron phosphate batteries with calcium chloride in a predetermined stoichiometric ratio;heating the reaction mixture in a chemical reaction chamber under controlled temperature conditions to initiate and complete a reaction that converts lithium compounds in the black mass into lithium chloride, while generating by-products;cooling the reaction mixture and separating the solid by-products from the reacted mass;leaching the reacted mass by dissolving the lithium chloride into water and filtering undissolved solids to obtain a lithium chloride solution;crystallizing and purifying lithium chloride from the solution by evaporation, recrystallization, or roasting techniques to achieve the desired purity level;performing quality control testing on the purified lithium chloride to ensure conformity to industrial standards; and,treating waste by-products, including scrubbing gaseous emissions and separating solid by-products for disposal or reuse in industrial applications.The method as claimed in claim 6, wherein the step of preparing the reaction mixture comprises reducing the black mass into powdered form and thoroughly mixing the powder with calcium chloride, and wherein, the step of heating comprises maintaining the reaction chamber at a temperature of at least 400 °C to ensure complete reaction, and wherein, the step of heating further comprises maintaining the reaction mixture under elevated temperature for a preset duration, and wherein, the step of cooling and separating comprises collecting calcium fluorophosphate and iron oxide residues for potential use as fertilizers or industrial additives.The method as claimed in claim 6, wherein the leaching step comprises mixing the reacted mass with water at a solid-to-liquid ratio of at least 1:0.5 under agitation and filtering out insoluble particles, and generating crystals from solution using evaporation wherein, the purification step further comprises heating the lithium chloride crystals to at least a temperature of 150 °C to convert ferric chloride impurities into ferric oxide prior to recrystallization of lithium chloride.The method as claimed in claim 6, wherein the purification step comprises recrystallization achieve pure lithium chloride, and wherein, the step of waste treatment comprises scrubbing chlorine gas released during the reaction using wet chemical scrubbers and collecting iron oxide residues for reuse.

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