Fluorine-containing lithium material recovery processing method

Abstract

The invention discloses a fluorine-containing lithium material recycling method which comprises the following steps: collecting a waste lithium battery, discharging and disassembling the collected waste lithium battery, and separating out a positive electrode material, a negative electrode material, a diaphragm and an electrolyte; respectively crushing the separated positive electrode material, negative electrode material and electrolyte by using a crusher, and screening by using a lithium battery screening machine to obtain a fluorine-containing lithium material mixture; mixing the obtained fluorine-containing lithium material mixture with an organic solvent, performing ultrasonic treatment by using ultrasonic sonochemical equipment to dissolve the fluorine-containing lithium material in the organic solvent, and performing filtration separation to obtain an organic solution of the fluorine-containing lithium material; the organic solvent extraction and reduced pressure distillation technology is adopted, harmful gas and waste water are avoided, the recycled fluorine-containing lithium material is used for preparing a new lithium battery or other purposes, green and environment-friendly recycling is achieved, the problem of separation and recycling of the fluorine-containing lithium material can be effectively solved, the recycling efficiency is greatly improved, and the method is suitable for industrial production. And more precious resources can be recycled.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium battery recycling, and particularly relates to a method for recycling and treating fluorine-containing lithium materials. Background Art

[0002] With the wide application of lithium batteries, the recycling and treatment of waste lithium batteries are particularly important in the current social context. With the popularization of electronic products such as electric vehicles and smart phones, the usage of lithium batteries has increased sharply, which has also led to a rapid growth in the number of waste lithium batteries. These waste lithium batteries not only occupy a large amount of land resources, but also may pose potential threats to the environment and human health. However, waste lithium batteries are also a huge "resource treasure house", and materials such as cobalt, lithium, copper and plastics in them all have high recycling value. The recycling and treatment of waste lithium batteries have become an urgent problem to be solved. Fluorine-containing lithium materials (such as LiPF6, LiF, etc.) are important components of lithium battery electrolytes and electrode materials and have high recycling value. Traditional methods are difficult to effectively separate and recycle fluorine-containing lithium materials, resulting in low recovery rates. As fluorine-containing hazardous wastes, adding lime for neutralization treatment, some recycling processes will produce harmful gases or waste water, causing secondary pollution to the environment. Existing technologies often involve multiple reaction and separation processes, with complex process flows and high costs. They are downgraded to low-grade lithium fluoride and used as ceramic additives, etc. Therefore, we need to provide a method for recycling and treating fluorine-containing lithium materials. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for recycling and treating fluorine-containing lithium materials, which adopts organic solvent extraction and vacuum distillation technologies, avoids the generation of harmful gases and waste water, uses the recycled fluorine-containing lithium materials to prepare new lithium batteries or for other purposes, realizes green and environmental protection recycling, can effectively solve the problem of separating and recycling fluorine-containing lithium materials, will greatly improve the recycling efficiency, and enables more precious resources to be recycled, so as to solve the problems in the prior art that it is difficult to effectively separate and recycle fluorine-containing lithium materials, resulting in low recovery rates, as fluorine-containing hazardous wastes, adding lime for neutralization treatment, some recycling processes will produce harmful gases or waste water, causing secondary pollution to the environment, existing technologies often involve multiple reaction and separation processes, with complex process flows and high costs, and are downgraded to low-grade lithium fluoride and used as ceramic additives, etc.

[0004] To achieve the above object, the present invention adopts the following technical scheme: A method for recycling and treating fluorine-containing lithium materials, comprising the following steps: Collect waste lithium batteries, discharge and disassemble the collected waste lithium batteries, and separate the positive electrode material, negative electrode material, separator and electrolyte; Respectively use a crusher to crush and a lithium battery screening machine to screen the separated positive electrode material, negative electrode material and electrolyte to obtain a mixture of fluorine-containing lithium materials; Mix the obtained fluorine-containing lithium material mixture with an organic solvent, and perform ultrasonic treatment using an ultrasonic sonochemical device to dissolve the fluorine-containing lithium material in the organic solvent, and then perform filtration separation to obtain an organic solution of the fluorine-containing lithium material; Perform vacuum distillation treatment on the obtained organic solution of the fluorine-containing lithium material through a vacuum distillation device to separate the organic solvent and the fluorine-containing lithium material, and obtain a high-purity lithium fluoride product.

[0005] Preferably, the discharging of the waste lithium battery includes a chemical discharging method; Chemical discharging method: Achieve rapid discharging by means of an electrolyte solution. Immerse the battery completely in an electrolyte solution of 5% sodium chloride solution, with the solution conductivity of 10 15mS / cm and the temperature needs to be maintained at 25 - 35°C.

[0006] Preferably, the disassembling of the waste lithium battery includes crushing the lithium battery through a crusher.

[0007] Preferably, use a gravity separator, a magnetic separator, and an eddy current separator to separate the positive electrode material, negative electrode material, separator, and electrolyte; The sorting speed of the gravity separator is 1.0 s / chip at 2x2 mm; The cylinder rotation speed of the magnetic separator is 25 r / min; The eddy current separator is 900 pieces / minute.

[0008] Preferably, the organic solvent is one or more of carbonate solvents, ether solvents, or ketone solvents.

[0009] Preferably, the time of the ultrasonic sonochemical device is 10 - 60 minutes.

[0010] Preferably, the temperature of the vacuum distillation device is 50 - 100°C, and the vacuum degree is 0.01 - 0.1 MPa.

[0011] Preferably, select an organic solvent that is stable for dissolving the fluorine-containing lithium material, and perform stirring treatment through a stirrer during the mixing process.

[0012] Preferably, after the ultrasonic treatment, the fluorine-containing lithium material will dissolve in the organic solvent, destroying the agglomerated structure on the surface of the fluorine-containing lithium material and forming a uniform solution.

[0013] Preferably, after the dissolution process is completed, use filter paper for filtration separation to remove undissolved impurities and solid particles.

[0014] The technical effects and advantages of the present invention: A method for recycling and treating fluorine-containing lithium materials proposed by the present invention has the following advantages compared with the prior art: By adopting the organic solvent extraction and vacuum distillation technologies, the present invention avoids the generation of harmful gases and waste water, and uses the recovered fluorine-containing lithium materials for preparing new lithium batteries or other purposes, realizing green and environmental protection recycling, effectively solving the problems of separating and recycling fluorine-containing lithium materials, greatly improving the recycling efficiency, and enabling more precious resources to be recycled.

[0015] Other features and advantages of the present invention will be described in the following specification, and part of them will be obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structure pointed out in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of the structural steps of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] The present invention provides a method for recycling and processing fluorine-containing lithium materials as shown in Figure 1 the following, which includes the following steps: Collect used lithium batteries, discharge and disassemble the collected used lithium batteries, and separate the positive electrode material, negative electrode material, separator and electrolyte; Crush the separated positive electrode material, negative electrode material and electrolyte respectively using a crusher and screen them using a lithium battery screening machine to obtain a mixture of fluorine-containing lithium materials; Mix the obtained mixture of fluorine-containing lithium materials with an organic solvent, and perform ultrasonic treatment using an ultrasonic sonochemical device to dissolve the fluorine-containing lithium materials in the organic solvent, and then perform filtration separation to obtain an organic solution of fluorine-containing lithium materials; Perform vacuum distillation treatment on the obtained organic solution of fluorine-containing lithium materials through a vacuum distillation device to separate the organic solvent and fluorine-containing lithium materials, and obtain a high-purity lithium fluoride product.

[0019] The discharge of the used lithium battery includes a chemical discharge method; Chemical discharge method: Achieve rapid discharge with the help of an electrolyte solution. Immerse the battery completely in an electrolyte solution of 5% sodium chloride solution, and the conductivity of the solution is 10 15mS / cm , and the temperature needs to be maintained at 25 - 35 °C; Specifically, it also includes the physical discharge method: by connecting an external load to consume the residual electric energy, placing the waste lithium battery in a discharge cabinet, constructing a closed circuit with parallel resistors, and using metal probes to contact the positive and negative electrodes of the battery to achieve discharge; Among them, the chemical discharge method mainly uses chemical reactions to reduce the voltage of the battery, thereby consuming the electric energy inside the battery. This method usually involves immersing the battery in a certain conductive solution and discharging it through the way of electrolytic energy release.

[0020] Prepare the solution: First of all, a conductive solution needs to be prepared. Commonly used ones include sodium chloride solution, sodium sulfate solution, etc. These solutions should have good conductivity to ensure the smooth progress of the discharge process.

[0021] Immerse the battery: Immerse the waste lithium battery to be discharged in the prepared conductive solution. Ensure that the battery is completely immersed so that the solution can fully contact the electrolyte inside the battery.

[0022] Connect the circuit: Connect the positive and negative electrodes of the battery to the external circuit to form a closed loop. This loop allows current to pass through, thereby consuming the electric energy inside the battery.

[0023] Control the discharge: During the discharge process, it is necessary to control the discharge speed and time to ensure that the battery can be discharged safely and effectively. Too fast discharge speed may cause the battery to overheat or cause other safety problems, while too long discharge time may waste time and resources.

[0024] Monitor and record: During the discharge process, the voltage and current changes of the battery should be monitored regularly and the relevant data should be recorded. These data can be used to evaluate the discharge effect and provide reference for subsequent battery treatment.

[0025] The disassembly of the waste lithium battery includes crushing the lithium battery by a crusher; Specifically, commonly used crushing equipment includes a primary shredder, a secondary multi-knife crusher, a tertiary grinder, etc. The waste lithium battery is first fed into the primary shredder by a conveyor for preliminary shredding, and the shredded material is fed into the secondary multi-knife crusher by a conveyor for further crushing to break the battery into smaller pieces. The crushed material may still need to be finely crushed by a tertiary grinder to meet the required particle size requirements. During the crushing process, ferromagnetic materials (such as iron nails, screws, etc.) in the material can be separated by setting magnetic separation equipment. The crushed material may also contain different components such as positive and negative electrode plates, separator paper, copper foil, and aluminum foil. These components can be separated by methods such as air flow separation and vibration screening.

[0026] Using a gravity screening machine, a magnetic screening machine and an eddy current screening machine to separate the positive electrode material, negative electrode material, separator and electrolyte; The sorting speed of the gravity separator is 1.0 s / chip at 2x2 mm; The cylinder rotation speed of the magnetic separator is 25 r / min; The eddy current separator is 900 pieces / minute; Specifically, the gravity separator uses a vibrating or inclined conveyor belt to stratify and separate materials under the action of gravity according to density and particle size. The gravity separator has limited separation effect on diaphragms and electrolytes, but can be used to preliminarily separate metal particles with larger density (such as metal oxides in the cathode material); The magnetic separator separates ferromagnetic substances from the materials by attracting them with a strong magnetic field. Some metal oxides in the cathode material (such as oxides containing elements such as iron and nickel) may be separated by the magnetic separator. The anode material (such as graphite, silicon, etc.) is usually not a ferromagnetic substance and thus will not be separated by the magnetic separator. The diaphragm and electrolyte do not contain ferromagnetic substances and thus will not be affected by the magnetic separator; The eddy current separator generates a high-frequency alternating strong magnetic field on the surface of the sorting magnetic roller. When a conductive non-ferrous metal passes through the magnetic field, eddy currents will be induced in the non-ferrous metal. The eddy currents themselves will generate a magnetic field opposite to the direction of the original magnetic field, so that the non-ferrous metal is subjected to the repulsive force of the magnetic field and leaps forward along its conveying direction to achieve separation from other non-metallic substances.

[0027] The organic solvent is one or more of carbonate solvents, ether solvents or ketone solvents; Specifically, carbonate solvents are one of the common organic solvents in electrolytes. They usually have good solubility and stability and can meet the requirements of electrolytes for solvents. Common carbonate solvents include dimethyl carbonate (DMC), diethyl carbonate (DEC), ethylene carbonate (EC), etc. These solvents play a role in transferring lithium ions in lithium batteries and are an important part of electrolytes; Ether solvents are also one of the commonly used organic solvents in electrolytes. They usually have low viscosity and high dielectric constant, which is beneficial to improving the charge and discharge performance and cycle stability of lithium batteries. Common ether solvents include ethylene glycol dimethyl ether (DME), tetraethylene glycol dimethyl ether (TEGDME), etc. These solvents also play a role in transferring lithium ions in lithium batteries and can be mixed with carbonate solvents to optimize the performance of electrolytes; Ketone solvents are also used in certain specific electrolyte formulations. They generally have high solubility and chemical stability, and can meet the requirements of some special application scenarios. However, compared with carbonate and ether solvents, the application of ketone solvents in lithium battery electrolytes is relatively less. Common ketone solvents include acetone, methyl ethyl ketone, etc. It should be noted that some ketone solvents such as acetone may be volatile, so corresponding safety measures need to be taken during the handling process.

[0028] The time of the ultrasonic sonochemical equipment is 10 - 60 minutes.

[0029] The temperature of the vacuum distillation device is 50 - 100 °C, and the vacuum degree is 0.01 - 0.1 MPa; Specifically, within this temperature range, the requirements for the heat source are relatively low, and general heating equipment can meet the needs. The temperature of the vacuum distillation device is 70 °C, which is conducive to the condensation of vapor, making the distillation process more efficient. Many organic substances are relatively stable within this temperature range and are not prone to adverse reactions such as decomposition, polymerization, or oxidation; The vacuum degree is 0.05 MPa. By reducing the pressure in the system (i.e., increasing the vacuum degree), the boiling point of the substance can be reduced, enabling distillation to be carried out at a lower temperature. At a higher vacuum degree, the number of gas molecules in the system decreases, reducing the risk of explosion and fire.

[0030] The selection is based on an organic solvent that is stable in dissolving fluorine-containing lithium materials, and the mixture is treated by stirring with a stirrer during the mixing process; Specifically, an organic solvent that can stably dissolve fluorine-containing lithium materials is selected. Fluorine-containing lithium materials such as lithium hexafluorophosphate are easily decomposed in air, so the selected solvent should have low reactivity to avoid chemical reactions with fluorine-containing lithium materials.

[0031] Fluorinated organic solvents, such as fluoroethylene carbonate (FEC) and difluoroethylene carbonate (DFEC), etc., have been widely concerned due to their good performance in the electrolyte solution of fluorine-containing lithium material batteries. These solvents can form thin and flexible lithium-ion conductive surface films with excellent protective properties, which helps to stabilize fluorine-containing lithium materials.

[0032] After the ultrasonic treatment, the fluorine-containing lithium materials will dissolve in the organic solvent, destroying the agglomerated structure on the surface of the fluorine-containing lithium materials and forming a uniform solution; Specifically, ultrasonic waves are sound waves with a frequency higher than 20000 Hz, which have the characteristics of good directivity, high energy, and strong penetration. In the treatment of lithium-ion battery materials, ultrasonic waves are often used to improve the dispersibility and uniformity of materials. When ultrasonic waves act on the mixture of fluorine-containing lithium materials and organic solvents, strong cavitation effects, mechanical effects, and thermal effects will be generated.

[0033] After the dissolution process is completed, filter separation is carried out using filter paper to remove undissolved impurities and solid particles; Specifically, select a suitable filter paper, usually according to the particle size and the properties of the solution to select the pore size of the filter paper.

[0034] Prepare a filtering device, such as a funnel, a bracket, and a receiving container (such as a beaker).

[0035] Assemble the filtering device: Fold the filter paper into a suitable shape and place it in the funnel, ensuring that the edges of the filter paper are tightly attached to the inner wall of the funnel to prevent the solution from flowing out through the gap between the filter paper and the funnel.

[0036] Place the funnel on the bracket and place the receiving container below.

[0037] Conduct filtration: Slowly pour the dissolved solution into the funnel, avoiding splashing of the liquid or impact on the filter paper resulting in rupture.

[0038] Observe the filtration rate of the filter paper. If necessary, gently stir the solution in the funnel to facilitate filtration.

[0039] After the solution has completely passed through the filter paper, check whether the solution in the receiving container is clear.

[0040] Working principle: Collect waste lithium batteries, discharge and disassemble the collected waste lithium batteries to separate the positive electrode material, negative electrode material, separator, and electrolyte; Crush the separated positive electrode material, negative electrode material, and electrolyte respectively using a crusher, and screen them using a lithium battery screening machine to obtain a mixture containing fluorine-containing lithium materials; Mix the obtained mixture containing fluorine-containing lithium materials with an organic solvent, and perform ultrasonic treatment using an ultrasonic sonochemical device to dissolve the fluorine-containing lithium materials in the organic solvent, and then perform filtration separation to obtain an organic solution of fluorine-containing lithium materials; Perform vacuum distillation treatment on the obtained organic solution of fluorine-containing lithium materials through a vacuum distillation device to separate the organic solvent and the fluorine-containing lithium materials to obtain a high-purity lithium fluoride product.

[0041] In addition, when the above-mentioned text creation unit, image generation unit, high-quality image training unit, and model optimization processing unit are executed, they are also used to implement other functions of the above-mentioned method for recycling and processing fluorine-containing lithium materials, which will not be elaborated one by one here.

[0042] In addition, the present invention also provides a terminal device. The method for recycling and processing fluorine-containing lithium materials involved in this embodiment is mainly applied to the terminal device, and the terminal device can be a device with display and processing functions such as a PC, a portable computer, a mobile terminal, etc.

[0043] Specifically, the terminal device may include a processor (such as a CPU), a communication bus, a user interface, a network interface, and a memory. Among them, the communication bus is used to implement connection communication between these components; the user interface may include a display screen (Display) and an input unit such as a keyboard (Keyboard); the network interface may optionally include a standard wired interface and a wireless interface (such as a WI-FI interface); the memory may be a high-speed RAM memory or a stable memory (non-volatile memory), such as a disk memory, and the memory may optionally also be a storage device independent of the aforementioned processor.

[0044] Among them, a readable storage medium is stored in the memory, and a fluorine-containing lithium material recovery processing program is stored in the readable storage medium. The processor can call the fluorine-containing lithium material recovery processing program stored in the memory and execute the fluorine-containing lithium material recovery processing method provided by the embodiments of the present invention.

[0045] It can be understood that a computer-readable storage medium can be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disk read-only memory (CD-ROM), digital versatile disk (DVD), memory stick, floppy disk, mechanically encoded device, such as a punched card or raised structure in a groove storing instructions thereon, and any suitable combination of the above. The computer-readable storage medium used herein is not construed as an instantaneous signal itself, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagated through a waveguide or other transmission medium (e.g., optical pulses through an optical fiber cable), or electrical signals transmitted through wires.

[0046] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to various computing / processing devices, or downloaded to an external computer or external storage device through a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include copper transmission cables, fiber optic transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0047] Computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state-setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages such as Smalltalk, C++, etc., and conventional procedural programming languages such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider). In some embodiments, by using the state information of the computer-readable program instructions to customize an electronic circuit, such as a programmable logic circuit, a field-programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit can execute the computer-readable program instructions to implement various aspects of the present disclosure.

[0048] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art may still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for recycling and treating fluorine-containing lithium materials, characterized in that, It includes the following steps: Collect waste lithium batteries, discharge and disassemble the collected waste lithium batteries, and separate the positive electrode material, negative electrode material, separator and electrolyte; Crush the separated positive electrode material, negative electrode material and electrolyte respectively using a crusher and screen them using a lithium battery screening machine to obtain a mixture containing fluorine-lithium materials; Mix the obtained mixture containing fluorine-lithium materials with an organic solvent, and perform ultrasonic treatment using an ultrasonic sonochemical device to dissolve the fluorine-lithium materials in the organic solvent, and then perform filtration separation to obtain an organic solution of fluorine-lithium materials; Perform vacuum distillation treatment on the obtained organic solution of fluorine-lithium materials through a vacuum distillation device to separate the organic solvent and fluorine-lithium materials, and obtain a high-purity lithium fluoride product.

2. The method for recycling and treating fluorine-containing lithium materials according to claim 1, wherein: The discharge of the waste lithium battery includes a chemical discharge method; Chemical discharge method: Achieve rapid discharge by means of an electrolyte solution. Immerse the battery completely in the electrolyte solution of 5% sodium chloride solution, and the conductivity of the solution is 10 15mS / cm 、The temperature needs to be maintained at 25 - 35 °C.

3. A method for recycling and treating fluorine-containing lithium materials according to claim 1, characterized in that: The disassembly of the waste lithium battery includes crushing the lithium battery through a crusher.

4. The method for recycling and treating fluorine-containing lithium materials according to claim 3, characterized in that: Use a gravity separator, magnetic separator and eddy current separator to separate the positive electrode material, negative electrode material, separator and electrolyte; The sorting speed of the gravity separator is 1.0 s / chip at 2x2 mm; The cylinder rotation speed of the magnetic separator is 25 r / min; The eddy current separator is 900 pieces / minute.

5. A method for recycling and treating fluorine-containing lithium materials according to claim 1, characterized in that: The organic solvent is one or more of carbonate solvents, ether solvents or ketone solvents.

6. The method for recycling and treating fluorine-containing lithium materials according to claim 1, wherein: The time of the ultrasonic sonochemical device is 10 - 60 minutes.

7. A method for recycling and treating fluorine-containing lithium materials according to claim 1, characterized in that: The temperature of the vacuum distillation device is 50 - 100 °C, and the vacuum degree is 0.01 - 0.1 MPa.

8. A method for recycling and treating fluorine-containing lithium materials according to claim 1, characterized in that: Select an organic solvent that is stable for dissolving fluorine-lithium materials, and perform stirring treatment through a stirrer during the mixing process.

9. A method for recycling and treating fluorine-containing lithium materials according to claim 6, characterized in that: After the ultrasonic treatment, the fluorine-lithium materials will dissolve in the organic solvent, destroying the agglomeration structure on the surface of the fluorine-lithium materials and forming a uniform solution.

10. A method for recycling and treating fluorine-containing lithium materials according to claim 9, characterized in that: After the dissolution process is completed, use filter paper for filtration separation to remove undissolved impurities and solid particles.

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