Resource utilization method of waste lithium iron phosphate battery

Abstract

The invention discloses a waste lithium iron phosphate battery resource utilization method, and relates to the technical field of waste lithium battery resource treatment, and the waste lithium iron phosphate battery resource utilization method comprises the following steps: disassembling and crushing waste lithium iron phosphate batteries, carrying out heat treatment, leaching the heat-treated waste lithium iron phosphate battery particles, and extracting metal elements, specific microorganisms are inoculated to accelerate extraction of metal elements, metal ions in the leachate are extracted through a supercritical carbon dioxide extraction technology, the metal ions are purified into metal resources through precipitation, filtration and electrolysis, and through optimization of all links and application of an innovative technology, the metal resources are obtained. The resource utilization efficiency of the waste lithium iron phosphate batteries is improved to the maximum extent, the environmental pollution is reduced, the waste treatment cost is reduced, efficient recovery and environment-friendly treatment of metal resources are ensured, and the method not only has remarkable environmental benefits, but also has good economic benefits, and meets the requirements of green chemistry and sustainable development.

Description

Technical Field

[0001] The present invention relates to the technical field of resource treatment of waste lithium batteries, and particularly to a method for resource utilization of waste lithium iron phosphate batteries. Background Art

[0002] With the rapid development of the global electric vehicle market and renewable energy, the application of lithium iron phosphate batteries is becoming increasingly widespread. However, the rapid popularization of lithium iron phosphate batteries has also brought a large demand for the recycling and treatment of waste batteries. If not effectively treated, it will not only waste precious metal resources but also cause serious environmental pollution. Traditional methods for recycling lithium iron phosphate batteries generally have the disadvantages of high energy consumption, heavy pollution, and low metal recovery rate. In addition, although some emerging technologies such as the combination of mechanical treatment and solvent leaching have certain economic efficiency, their impact on the environment and resource utilization efficiency still do not reach the ideal level. Therefore, the development of an efficient and environmentally friendly method for resource utilization of lithium iron phosphate batteries has become a research hotspot in this field;

[0003] Traditional heat treatment methods usually produce harmful gases and solid waste, leading to potential environmental pollution. Existing leaching technologies mostly use strong acid and strong base solvents, which not only seriously corrode equipment but also produce a large amount of difficult-to-treat waste liquid. In the separation and purification of metal ions, traditional precipitation and extraction technologies are less efficient and it is difficult to achieve the recovery of high-purity metal resources. The present invention combines heat treatment with environmentally friendly solvent leaching, uses microbial inoculation to accelerate metal extraction, and uses supercritical carbon dioxide extraction and electrochemical technologies for efficient separation and purification of metal ions. Compared with the existing technologies, this method not only improves the metal recovery rate but also significantly reduces environmental pollution, having important economic and ecological value. Summary of the Invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a method for resource utilization of waste lithium iron phosphate batteries to solve the problem that in the separation and purification of metal ions, traditional precipitation and extraction technologies are less efficient and it is difficult to achieve the recovery of high-purity metal resources.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for resource utilization of waste lithium iron phosphate batteries, which includes,

[0008] Disassembling, crushing the waste lithium iron phosphate batteries and removing impurities through heat treatment;

[0009] Using a new type of environmentally friendly solvent to leach the waste lithium iron phosphate battery particles after heat treatment to extract metal elements;

[0010] Inoculate specific microorganisms to accelerate the extraction of metal elements and obtain a leaching solution containing metal ions;

[0011] Extract metal ions from the leaching solution through supercritical carbon dioxide extraction technology;

[0012] Adopt precipitation, filtration and electrolysis methods to purify metal ions into high-purity metal resources;

[0013] Treat waste liquid and waste residues through chemical neutralization and physical separation to achieve maximum resource recovery.

[0014] As a preferred embodiment of the method for recycling waste lithium iron phosphate batteries described in the present invention, wherein: the steps of disassembling, crushing and removing impurities from waste lithium iron phosphate batteries through heat treatment are as follows:

[0015] Conduct a preliminary inspection on waste lithium iron phosphate batteries and classify and manage them according to the battery shape, model and type;

[0016] Use a hydraulic disassembly machine to disassemble the battery casing, separately recycle the disassembled aluminum and steel casings, disassemble the disassembled battery packs one by one, remove the circuit board, connecting wire and protection board, and clean the electrolyte inside the battery;

[0017] Use a hammer crusher to crush the disassembled waste lithium iron phosphate battery materials, and use a laser particle size analyzer to monitor the size distribution of waste lithium iron phosphate battery particles;

[0018] Feed the waste lithium iron phosphate battery particles into a heating furnace for heating to remove plastics, paper materials, harmful gases and residual electrolyte in the waste battery. During the heat treatment process, argon is used as a protective atmosphere.

[0019] As a preferred embodiment of the method for recycling waste lithium iron phosphate batteries described in the present invention, wherein: the steps of leaching the heat-treated waste lithium iron phosphate battery particles with a new type of environmentally friendly solvent to extract metal elements are as follows:

[0020] Select a citric acid-based complexing agent as the new type of environmentally friendly solvent, and set a formula for determining the best leaching efficiency, and the expression is:

[0021]

[0022] Among them, E represents the leaching efficiency of metal elements, M represents the total mass of metals in the battery material, L represents the concentration of the citric acid-based complexing agent, V1 represents the volume of the citric acid-based complexing agent, k represents the temperature-dependent rate constant, T represents the leaching temperature, e represents the natural logarithm base, and t0 represents the starting time of leaching;

[0023] Determine the concentration of the optimal citric acid-based complexing agent according to maximizing the leaching efficiency E of metal elements, prepare the citric acid-based complexing agent with the corresponding concentration, and place the heat-treated waste lithium iron phosphate battery particles in the citric acid-based complexing agent for leaching to extract metal elements.

[0024] As a preferred embodiment of the method for resource utilization of the waste lithium iron phosphate battery described in the present invention, wherein: inoculating specific microorganisms to accelerate the extraction of metal elements to obtain a leaching solution containing metal ions, the specific steps are as follows:

[0025] Select Acidithiobacillus ferrooxidans as the inoculated microorganism and pre-culture it in a nutrient solution containing appropriate amounts of ferric sulfate and copper sulfate;

[0026] Inoculate the pre-cultured Acidithiobacillus ferrooxidans into the solution mixed with the heat-treated waste lithium iron phosphate battery material and the citric acid-based complexing agent, and set the biological enhancement factor B, the expression is:

[0027]

[0028] wherein, C represents the density of inoculated Acidithiobacillus ferrooxidans, D represents the metal ion concentration in the solution, α represents the temperature sensitivity coefficient, Q represents the actual temperature during inoculation, and Q0 represents the starting temperature of inoculation;

[0029] Maximize the solution of the biological enhancement factor B to obtain the optimal inoculation conditions when the biological enhancement factor B is maximized, and inoculate Acidithiobacillus ferrooxidans under the optimal inoculation conditions to obtain a leaching solution containing metal ions.

[0030] As a preferred embodiment of the method for resource utilization of the waste lithium iron phosphate battery described in the present invention, wherein: extracting metal ions from the leaching solution by supercritical carbon dioxide extraction technology, the specific steps are as follows:

[0031] Use diluted sulfuric acid and sodium hydroxide solution to titrate the leaching solution containing metal ions, adjust the pH value of the leaching solution to the optimal range suitable for supercritical carbon dioxide extraction, and filter the titrated leaching solution containing metal ions;

[0032] Transfer the pretreated leaching solution to a high-pressure reactor for extraction, and calculate the extraction efficiency, the expression is:

[0033]

[0034] wherein, Z represents the extraction efficiency of metal ions, P represents the pressure of supercritical carbon dioxide, R represents the ideal gas constant, β represents the temperature sensitivity coefficient, Y represents the actual temperature during extraction, Y0 represents the starting temperature of extraction, and V2 represents the volume of the metal leaching solution;

[0035] Set a threshold θ. When Z ≤ θ, it indicates that the extraction efficiency is low and does not meet the requirements. Continue to optimize and adjust the optimal extraction conditions until Z > θ;

[0036] When Z > θ, it indicates that the extraction efficiency is high and meets the requirements. According to the pressure P of the supercritical carbon dioxide and the actual temperature Y during the extraction process, perform extraction to obtain an extraction solution rich in metal ions.

[0037] As a preferred embodiment of the method for resource utilization of waste lithium iron phosphate batteries described in the present invention, wherein: the method of using precipitation, filtration, and electrolysis to purify metal ions into high-purity metal resources specifically includes the following steps:

[0038] After supercritical carbon dioxide extraction, add sodium hydroxide to the obtained extraction solution rich in metal ions to form metal precipitates;

[0039] Optimize the precipitation efficiency through maximization solving. The expression is:

[0040]

[0041] Wherein, S represents the precipitation efficiency, A represents the initial concentration of metal ions, V3 represents the volume of the extraction solution rich in metal ions, γ represents the reaction rate constant, λ represents the pH sensitivity coefficient, δ represents the actual pH of the precipitation reaction, and δ0 represents the ideal pH;

[0042] Separate the precipitate from the mother liquor through a high-efficiency vacuum filtration device and wash the precipitate;

[0043] Electrolyze the washed precipitate.

[0044] As a preferred embodiment of the method for resource utilization of waste lithium iron phosphate batteries described in the present invention, wherein: the electrolysis of the washed precipitate specifically includes the following steps:

[0045] Select dilute sulfuric acid as the electrolyte, dissolve the precipitate in dilute sulfuric acid to prepare an electrolyte containing metal ions, place the electrolyte containing metal ions in an electrolytic cell, set an anode and a cathode in the electrolytic cell, and electrolyze the electrolyte containing metal ions;

[0046] Optimize the metal recovery efficiency during the electrolysis process. The expression is:

[0047]

[0048] Wherein, τ represents the metal recovery efficiency, η represents the electrolysis efficiency, I represents the magnitude of the electrolysis current, J represents the electrolysis time, F represents the Faraday constant, and X represents the electrochemical equivalent of the metal;

[0049] Optimize the metal recovery efficiency τ by maximizing the solution;

[0050] Recycle the high-purity metal deposited on the cathode.

[0051] As a preferred embodiment of the method for resource utilization of waste lithium iron phosphate batteries described in the present invention, wherein: the waste liquid and waste residue are treated by chemical neutralization and physical separation to achieve maximum resource recovery. The specific steps are as follows:

[0052] Collect the waste liquid generated during the recovery process in a corrosion-resistant reaction kettle, neutralize the waste liquid by dropwise adding dilute ammonia water until the value of the waste liquid reaches neutral, and use a high-efficiency horizontal sedimentation centrifuge to separate the solid and liquid of the waste liquid;

[0053] For the waste liquid after solid-liquid separation, use modified biochar as a heavy metal adsorbent, and further reduce the concentration of heavy metal ions in the waste liquid through a continuous adsorption column experiment;

[0054] Detect the waste liquid after adsorption treatment by inductively coupled plasma mass spectrometry ICP-MS, compare the detected value with the user's required value. When the detected value exceeds the user's required value, continue the adsorption treatment until the heavy metal concentration does not exceed the user's required value;

[0055] When the detected value does not exceed the user's required value, discharge it into the sewage treatment plant for further treatment;

[0056] Dry the waste residue generated during the recovery process and the waste residue generated during the solid-liquid separation of the waste liquid, and send the dried waste residue into a pyrolysis reaction furnace for pyrolysis to generate inorganic powder for secondary utilization and recycle it.

[0057] In a second aspect, the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and: when the computer program is executed by the processor, any step of the method for resource utilization of waste lithium iron phosphate batteries described in the first aspect of the present invention is implemented.

[0058] In a third aspect, the present invention provides a computer-readable storage medium, on which a computer program is stored, and: when the computer program is executed by the processor, any step of the method for resource utilization of waste lithium iron phosphate batteries described in the first aspect of the present invention is implemented.

[0059] The beneficial effects of the present invention are as follows: By utilizing the ability of the citrate-based complexing agent to form stable complexes with metal ions, metals are effectively separated from battery materials. It not only has biodegradability, reducing the risk of chemical pollution, but also lowers the treatment cost. Biological means are introduced to enhance chemical reactions, accelerating the extraction rate of metal ions and the concentration of metal ions. Compared with relying on chemical methods, this method is more environmentally friendly because no additional harmful reagents need to be added. The use of supercritical carbon dioxide extraction technology significantly improves the resource utilization rate and also lays a foundation for subsequent purification work, ensuring the high quality of the final product. The by-products generated during the process are also reasonably disposed of, embodying the concept of circular economy. The final product meets industrial standards and provides reliable support for downstream industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0061] Figure 1 It is a flowchart of the resource utilization method for waste lithium iron phosphate batteries in Example 1.

[0062] Figure 2 It is a schematic diagram of the high-purity metal recovery process in Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0063] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will provide a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings of the specification.

[0064] Many specific details are set forth in the following description to facilitate a thorough understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0065] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or alternative embodiments that exclude other embodiments.

[0066] Example 1, refer to Figure 1 and Figure 2, which is the first embodiment of the present invention. This embodiment provides a method for the resource utilization of waste lithium iron phosphate batteries, including the following steps:

[0067] S1. Disassemble, crush the waste lithium iron phosphate batteries and remove impurities through heat treatment;

[0068] Conduct a preliminary inspection on the waste lithium iron phosphate batteries to ensure that there are no safety hazards such as leakage or deformation. Classify and manage them according to the battery shape, model and type.

[0069] Use a hydraulic disassembly machine to disassemble the battery casing, separately recycle the disassembled aluminum and steel casings, disassemble the battery packs one by one, remove the circuit boards, connecting wires and protection boards, and clean the electrolyte inside the batteries.

[0070] Use a hammer crusher to crush the disassembled waste lithium iron phosphate battery materials, and use a laser particle size analyzer to monitor the size distribution of the waste lithium iron phosphate battery particles to ensure that the sizes of the waste lithium iron phosphate battery particles are uniform.

[0071] Send the waste lithium iron phosphate battery particles into a heating furnace for heating to remove plastics, paper materials, harmful gases and residual electrolyte in the waste batteries. During the heat treatment process, use argon as a protective atmosphere to prevent the generation of harmful gases and reduce oxidation reactions.

[0072] By disassembling and crushing the waste lithium iron phosphate batteries and using heat treatment to remove impurities, the effective separation of metal elements in the waste batteries is achieved, and the interfering substances in the subsequent treatment process are reduced. In this step, plastics, paper materials and harmful gases in the batteries are removed through heat treatment to ensure the purity and safety of subsequent operations. In addition, using argon as a protective atmosphere prevents the occurrence of oxidation reactions and maintains the stability of the metal resources in the waste batteries, laying a foundation for subsequent metal extraction.

[0073] S2. Use a new type of environmentally friendly solvent to leach the heat-treated waste lithium iron phosphate battery particles to extract metal elements;

[0074] Select a citric acid-based complexing agent as the new type of environmentally friendly solvent. To maximize the extraction efficiency of metal elements and adjust the concentration of the citric acid-based complexing agent, set a formula for determining the optimal leaching efficiency, and the expression is:

[0075]

[0076] Among them, E represents the leaching efficiency of metal elements, M represents the total mass of metals in the battery material, L represents the concentration of the citric acid-based complexing agent, V1 represents the volume of the citric acid-based complexing agent, k represents the temperature-dependent rate constant, T represents the leaching temperature, e represents the base of the natural logarithm, and t0 represents the starting time of leaching;

[0077] By using a citric acid-based complexing agent to leach waste lithium iron phosphate battery particles, metal elements can be efficiently extracted, and the use of environmentally friendly solvents reduces the use of harmful chemicals, meeting the requirements of environmental protection;

[0078] The value range of E is [0, 1]. The optimal concentration of the citric acid-based complexing agent is determined according to the maximum solution of the leaching efficiency E of metal elements, and the corresponding concentration of the citric acid-based complexing agent is prepared. The heat-treated waste lithium iron phosphate battery particles are placed in the citric acid-based complexing agent for leaching to extract metal elements;

[0079] This step precisely adjusts the concentration of the citric acid-based complexing agent by setting an optimization formula to maximize the extraction efficiency of metal elements, reduce resource waste, and improve the accuracy and efficiency of metal recovery at the same time.

[0080] S3. Inoculate specific microorganisms to accelerate the extraction of metal elements to obtain a leaching solution containing metal ions;

[0081] Select Acidithiobacillus ferrooxidans as the inoculated microorganism, select a strain of Acidithiobacillus ferrooxidans with high activity and strong adaptability from the strains preserved in the laboratory, and pre-culture it in a nutrient solution containing appropriate amounts of ferric sulfate and copper sulfate;

[0082] Inoculate the pre-cultured Acidithiobacillus ferrooxidans into the solution mixed with the heat-treated waste lithium iron phosphate battery material and the citric acid-based complexing agent, and set the biological enhancement factor B to determine the optimal inoculation conditions. The expression is:

[0083]

[0084] Among them, C represents the density of inoculated Acidithiobacillus ferrooxidans, D represents the concentration of metal ions in the solution, α represents the temperature sensitivity coefficient, Q represents the actual temperature during inoculation, and Q0 represents the starting temperature of inoculation;

[0085] The extraction of metal elements is accelerated by inoculating specific Acidithiobacillus ferrooxidans. This step significantly improves the extraction efficiency of metal elements through biological enhancement. The density C of inoculated Acidithiobacillus ferrooxidans is the optimal;

[0086] Maximize the solution of the biological enhancement factor B to obtain the optimal inoculation conditions when the biological enhancement factor B is maximized. Inoculate Acidithiobacillus ferrooxidans under the optimal inoculation conditions to obtain a leaching solution containing metal ions;

[0087] By optimizing the inoculation conditions of microorganisms, including inoculation density and temperature, the dissolution rate of metal ions can be increased to ensure that the concentration of metal ions in the leaching solution meets the requirements. This method reduces the use of chemical agents through biological action, improves the environmental friendliness of the extraction process, and can efficiently complete the extraction of metals in a relatively short time.

[0088] S4. Extract metal ions from the leaching solution through supercritical carbon dioxide extraction technology;

[0089] Pretreat the metal-containing leaching solution, titrate it with diluted sulfuric acid and sodium hydroxide solutions, adjust the pH value of the metal-containing leaching solution to the optimal range of 3.0 - 4.5 suitable for supercritical carbon dioxide extraction, filter the metal-containing leaching solution to ensure that there are no impurities and suspended particles affecting the extraction effect in the metal-containing leaching solution, and add an appropriate amount of sodium dodecyl sulfate to the leaching solution according to relevant industry specifications to enhance the interaction between metal ions and carbon dioxide and improve the extraction efficiency;

[0090] Transfer the pretreated metal-containing leaching solution to a high-pressure reactor for extraction, and set the formula for determining the optimal extraction conditions, with the expression:

[0091]

[0092] Among them, Z represents the extraction efficiency of metal ions, with a value range of [0, 1], P represents the pressure of supercritical carbon dioxide, R represents the ideal gas constant, β represents the temperature sensitivity coefficient, Y represents the actual temperature during the extraction process, Y0 represents the starting temperature of the extraction, and V2 represents the volume of the metal-containing leaching solution;

[0093] By using supercritical carbon dioxide extraction technology and combining precise temperature and pressure control, metal ions can be efficiently extracted from the leaching solution;

[0094] Set a threshold θ. When Z ≤ θ, it indicates that the extraction efficiency is low and does not meet the requirements, and continue to optimize and adjust the optimal extraction conditions until Z > θ;

[0095] When Z > θ, it indicates that the extraction efficiency is high and meets the requirements. Extract according to the pressure P of supercritical carbon dioxide and the actual temperature Y during the extraction process to obtain an extraction solution rich in metal ions;

[0096] Compared with traditional solvent extraction methods, this technology has higher extraction efficiency and selectivity, and can reduce solvent use and environmental pollution;

[0097] In addition, this technology avoids the use of toxic solvents in traditional chemical extraction, improving the safety and environmental protection of the extraction process.

[0098] S5. Purify metal ions into high-purity metal resources by means of precipitation, filtration and electrolysis;

[0099] After supercritical carbon dioxide extraction, add sodium hydroxide to the obtained extraction solution rich in metal ions to form metal ion precipitates;

[0100] Optimize the precipitation efficiency through maximizing solution, and the expression is:

[0101]

[0102] Among them, S represents the precipitation efficiency, and the value range is [0,1], A represents the initial concentration of metal ions, V3 represents the volume of the extraction solution rich in metal ions, γ represents the reaction rate constant, λ represents the pH sensitivity coefficient, δ represents the actual pH of the precipitation reaction, and δ0 represents the ideal pH;

[0103] Separate the precipitates from the mother liquor through a high-efficiency vacuum filtration device, and wash the precipitates to remove adsorbed impurities and excess precipitating agents;

[0104] Electrolyze the washed precipitates. Select dilute sulfuric acid as the electrolyte, dissolve the precipitates in dilute sulfuric acid to prepare an electrolyte containing metal ions, place the electrolyte containing metal ions in an electrolytic cell, set an anode and a cathode in the electrolytic cell, and electrolyze the electrolyte containing metal ions;

[0105] Optimize the metal recovery efficiency during the electrolysis process, and the expression is:

[0106]

[0107] Among them, τ represents the metal recovery efficiency, and the value range is [0,1], η represents the electrolysis efficiency, I represents the electrolysis current magnitude, J represents the electrolysis time, F represents the Faraday constant, and X represents the electrochemical equivalent of the metal;

[0108] The electrolysis process optimizes the parameters of the metal recovery efficiency, including adjusting the electrolysis current and electrolysis time to maximize the metal recovery efficiency τ, achieving efficient metal recovery. This step can further purify the metal, reduce energy consumption, and ensure the recovery of high-purity metal by controlling the electrolysis efficiency;

[0109] In addition, the optimized electrolysis process ensures the efficient operation of the electrolytic cell and improves the economic benefits of the overall metal recovery;

[0110] Optimize the metal recovery efficiency τ through maximizing solution;

[0111] Recycle the high-purity metal deposited on the cathode;

[0112] The purification of metal ions by precipitation, filtration and electrolysis methods can efficiently obtain high-purity metal resources;

[0113] By optimizing the precipitation process and electrolysis process, including adjusting the acidity and alkalinity and electrolysis efficiency, the recovery rate of metals can be maximized, the residue of impurities can be reduced, the purity of the recovered metals can be improved, and the high quality and high utilization rate of metal resources can be ensured.

[0114] S6. Through chemical neutralization and physical separation to treat waste liquid and waste residues, the maximum recovery of resources is achieved;

[0115] Collect the waste liquid generated during the recovery process in a corrosion-resistant reaction kettle, neutralize the waste liquid by dropwise addition of dilute ammonia water until the value of the waste liquid reaches neutral, and use a high-efficiency horizontal sedimentation centrifuge to separate the solid and liquid of the waste liquid;

[0116] Through neutralizing the waste liquid and physically separating the waste residues, the maximum recovery of resources is achieved and environmental pollution is reduced;

[0117] For the waste liquid after solid-liquid separation, use modified biochar as a heavy metal adsorbent, and further reduce the concentration of heavy metal ions in the waste liquid through continuous adsorption column experiments;

[0118] Detect the waste liquid after adsorption treatment by inductively coupled plasma mass spectrometry ICP-MS, compare the detected value with the user's required value. When the detected value exceeds the user's required value, continue the adsorption treatment until the heavy metal concentration does not exceed the user's required value;

[0119] When the detected value does not exceed the user's required value, it is discharged into the sewage treatment plant for further treatment;

[0120] Through continuous adsorption treatment and ICP-MS detection, after ensuring that the heavy metal concentration in the waste liquid meets the specified standards, then discharge it. This treatment step effectively avoids secondary pollution to the environment. At the same time, through precise detection and treatment, it ensures that the waste liquid meets the standards when finally discharged into the sewage treatment plant, conforms to environmental protection regulations. Through this process, the harmless treatment of waste liquid and waste residues is achieved, which helps to promote the sustainable development of the resource utilization of waste batteries;

[0121] Dry the waste residues generated during the recovery process and the waste residues generated from the solid-liquid separation of the waste liquid, send the dried waste residues into a pyrolysis reaction furnace for pyrolysis, and generate inorganic powder for secondary utilization for recycling;

[0122] This step further reduces the heavy metal concentration in the waste liquid by using a modified biochar adsorbent, ensures that the waste liquid discharge meets environmental protection standards, and avoids pollution to water bodies. At the same time, the pyrolysis treatment of the waste residues generates recyclable inorganic powder, further reducing resource waste and environmental burden.

[0123] This embodiment also provides a computer device applicable to the resource utilization method of waste lithium iron phosphate batteries, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the resource utilization method of waste lithium iron phosphate batteries proposed in the above embodiment.

[0124] The computer device can be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a carrier network, NFC (Near Field Communication), or other technologies. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a button, a trackball, or a touchpad provided on the housing of the computer device, or an external keyboard, a touchpad, or a mouse, etc.

[0125] This embodiment also provides a storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the resource utilization method of waste lithium iron phosphate batteries proposed in the above embodiment; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM for short), Electrically Erasable Programmable Read-Only Memory (EEPROM for short), Erasable Programmable Read Only Memory (EPROM for short), Programmable Red-Only Memory (PROM for short), Read-Only Memory (ROM for short), magnetic memory, flash memory, a magnetic disk, or an optical disc.

[0126] In summary, the present invention: Utilizes the ability of a citric acid-based complexing agent to form stable complexes with metal ions, effectively separating metals from battery materials. It not only has biodegradability, reducing the risk of chemical pollution, but also lowers the treatment cost. It introduces biological means to enhance chemical reactions, accelerating the extraction rate of metal ions and the concentration of metal ions. Compared with relying on chemical methods, this approach is more environmentally friendly because no additional harmful reagents are required. Using supercritical carbon dioxide extraction technology significantly improves resource utilization rate and also lays a foundation for subsequent purification work, ensuring the high quality of the final product. The by-products generated during the process are also reasonably disposed of, reflecting the concept of circular economy. The final product meets industrial standards and provides reliable support for downstream industries.

[0127] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for resource utilization of waste lithium iron phosphate batteries, characterized in that: including disassembling, crushing the waste lithium iron phosphate battery and removing impurities through heat treatment leaching the waste lithium iron phosphate battery particles after heat treatment with a new type of environmentally friendly solvent to extract metal elements inoculating specific microorganisms to accelerate the extraction of metal elements to obtain a leaching solution containing metal ions extracting metal ions in the leaching solution by supercritical carbon dioxide extraction technology purifying metal ions into high-purity metal resources by precipitation, filtration and electrolysis treating waste liquid and waste residue through chemical neutralization and physical separation to achieve maximum resource recovery 2. The resource utilization method of waste lithium iron phosphate batteries according to claim 1, characterized in that: The steps of disassembling, crushing the waste lithium iron phosphate battery and removing impurities through heat treatment are as follows conducting a preliminary inspection on the waste lithium iron phosphate battery and classifying and managing it according to the battery shape, model and type using a hydraulic disassembler to disassemble the battery shell, separately recycling the disassembled aluminum and steel shells, disassembling the disassembled battery packs one by one, removing the circuit board, connecting wire and protection board, and cleaning the electrolyte inside the battery using a hammer crusher to crush the disassembled waste lithium iron phosphate battery materials, and monitoring the size distribution of the waste lithium iron phosphate battery particles with a laser particle size analyzer feeding the waste lithium iron phosphate battery particles into a heating furnace for heating to remove plastics, paper materials, harmful gases and residual electrolyte in the waste battery. During the heat treatment process, argon is used as a protective atmosphere 3. The resource utilization method of waste lithium iron phosphate batteries according to claim 2, characterized in that: The steps of leaching the waste lithium iron phosphate battery particles after heat treatment with a new type of environmentally friendly solvent to extract metal elements are as follows selecting a citric acid-based complexing agent as the new type of environmentally friendly solvent and setting a formula for determining the optimal leaching efficiency, and the expression is where E represents the leaching efficiency of metal elements, M represents the total mass of metals in the battery material, L represents the concentration of the citric acid-based complexing agent, V1 represents the volume of the citric acid-based complexing agent, k represents the temperature-dependent rate constant, T represents the leaching temperature, e represents the natural number base, and t0 represents the starting time of leaching determining the optimal concentration of the citric acid-based complexing agent according to maximizing the leaching efficiency E of metal elements, preparing the citric acid-based complexing agent with the corresponding concentration, and placing the waste lithium iron phosphate battery particles after heat treatment in the citric acid-based complexing agent for leaching to extract metal elements 4. The resource utilization method of waste lithium iron phosphate batteries according to claim 3, characterized in that: The steps of inoculating specific microorganisms to accelerate the extraction of metal elements to obtain a leaching solution containing metal ions are as follows selecting Acidithiobacillus ferrooxidans as the inoculated microorganism and pre-culturing it in a nutrient solution containing appropriate amounts of ferric sulfate and copper sulfate inoculating the pre-cultured Acidithiobacillus ferrooxidans into a solution mixed with the waste lithium iron phosphate battery materials after heat treatment and the citric acid-based complexing agent, and setting the bioaugmentation factor B, and the expression is where C represents the density of inoculated Acidithiobacillus ferrooxidans, D represents the metal ion concentration in the solution, α represents the temperature sensitivity coefficient, Q represents the actual temperature during inoculation, and Q0 represents the starting temperature of inoculation Maximize the biological enhancement factor B to obtain the optimal inoculation conditions when the biological enhancement factor B is maximized. Under the optimal inoculation conditions, inoculate Acidithiobacillus ferrooxidans to obtain a leaching solution containing metal ions.

5. The resource utilization method of waste lithium iron phosphate batteries according to claim 4, characterized in that: The extraction of metal ions from the leaching solution by the supercritical carbon dioxide extraction technology is specifically carried out as follows: Use diluted sulfuric acid and sodium hydroxide solution to titrate the leaching solution containing metal ions, adjust the pH value of the leaching solution to the optimal range suitable for supercritical carbon dioxide extraction, and filter the titrated leaching solution containing metal ions; Transfer the pretreated leaching solution to a high-pressure reactor for extraction, and calculate the extraction efficiency. The expression is: Among them, Z represents the extraction efficiency of metal ions, P represents the pressure of supercritical carbon dioxide, R represents the ideal gas constant, β represents the temperature sensitivity coefficient, Y represents the actual temperature during the extraction process, Y0 represents the starting temperature of the extraction, and V2 represents the volume of the leaching solution of the metal; Set a threshold θ. When Z ≤ θ, it means that the extraction efficiency is low and does not meet the requirements. Continue to optimize and adjust the optimal extraction conditions until Z > θ; When Z > θ, it means that the extraction efficiency is high and meets the requirements. Extract according to the pressure P of supercritical carbon dioxide and the actual temperature Y during the extraction process to obtain an extraction solution rich in metal ions.

6. The resource utilization method of waste lithium iron phosphate batteries according to claim 5, characterized in that: The method of using precipitation, filtration and electrolysis to purify metal ions into high-purity metal resources is specifically carried out as follows: After supercritical carbon dioxide extraction, add sodium hydroxide to the obtained extraction solution rich in metal ions to form metal precipitates; Optimize the precipitation efficiency by maximizing the solution. The expression is: Among them, S represents the precipitation efficiency, A represents the initial concentration of metal ions, V3 represents the volume of the extraction solution rich in metal ions, γ represents the reaction rate constant, λ represents the pH sensitivity coefficient, δ represents the actual pH value of the precipitation reaction, and δ0 represents the ideal pH value; Separate the precipitate from the mother liquor through a high-efficiency vacuum filtration device and wash the precipitate; Electrolyze the washed precipitate.

7. The resource utilization method of waste lithium iron phosphate batteries according to claim 6, characterized in that: The electrolysis of the washed precipitate is specifically carried out as follows: Select dilute sulfuric acid as the electrolyte, dissolve the precipitate in dilute sulfuric acid to prepare an electrolyte containing metal ions, place the electrolyte containing metal ions in an electrolytic cell, set an anode and a cathode in the electrolytic cell, and electrolyze the electrolyte containing metal ions; Optimize the metal recovery efficiency during the electrolysis process. The expression is: Among them, τ represents the metal recovery efficiency, η represents the electrolysis efficiency, I represents the magnitude of the electrolysis current, J represents the electrolysis time, F represents the Faraday constant, and X represents the electrochemical equivalent of the metal; Optimize the metal recovery efficiency τ by maximizing the solution; Recycle and utilize the high-purity metal deposited on the cathode.

8. The resource utilization method of waste lithium iron phosphate batteries according to claim 7, characterized in that: The waste liquid and waste residue are treated by chemical neutralization and physical separation to achieve the maximum recovery of resources. The specific steps are as follows: Collect the waste liquid generated during the recovery process in a corrosion-resistant reaction kettle, neutralize the waste liquid by adding dilute ammonia drop by drop until the value of the waste liquid reaches neutral, and use a high-efficiency horizontal sedimentation centrifuge to separate the solid and liquid of the waste liquid; For the waste liquid after solid-liquid separation, modified biochar is used as a heavy metal adsorbent, and the concentration of heavy metal ions in the waste liquid is further reduced through a continuous adsorption column experiment; The waste liquid after adsorption treatment is detected by inductively coupled plasma mass spectrometry (ICP-MS), and the detected value is compared with the user's required value. When the detected value exceeds the user's required value, the adsorption treatment is continued until the heavy metal concentration does not exceed the user's required value; When the detected value does not exceed the user's required value, it is discharged into the sewage treatment plant for further treatment; The waste residue generated during the recovery process and the waste residue generated during the solid-liquid separation of the waste liquid are dried, and the dried waste residue is sent to a pyrolysis reaction furnace for pyrolysis to generate inorganic powder for secondary utilization and recovery.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the resource utilization method of the waste lithium iron phosphate battery according to any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the resource utilization method of the waste lithium iron phosphate battery according to any one of claims 1 to 8.

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