Multi-modal gradient parallel physical separation device and integrated system application

Abstract

The invention belongs to the technical field of lithium ion battery recovery, and particularly relates to a multi-mode gradient parallel physical separation device and an application method of an integrated system.The application method comprises the following steps that 1, waste lithium batteries are cut and sorted to obtain battery shells, diaphragms, electrolyte, positive plates and negative plates; (2) crushing the positive plate and the negative plate, roasting, crushing by adopting an airflow mill, and screening to obtain materials with different particle sizes; (3) carrying out color sorting on the oversize material, separating to obtain large-particle copper foil and aluminum foil, and winnowing the screened materials with different particle sizes in batches to obtain a copper foil, aluminum foil and positive electrode material mixture and a negative electrode material; and (4) sorting the positive electrode material mixture on conveyor belts with different inclinations to obtain the positive electrode material and a copper-aluminum foil material.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lithium ion battery recycling, and particularly relates to a physical separation device with multi-modal gradient parallel lines and application of an integrated system. BACKGROUND

[0002] With the wide application of lithium ion batteries in electric vehicles and energy storage fields, the number of waste lithium batteries has increased dramatically, and it is expected to show an explosive trend in the next 3-5 years. Improper disposal will lead to environmental risks such as heavy metal leakage and electrolyte evaporation, and cause resource waste. Current recycling processes mainly rely on pyrometallurgy or hydrometallurgy, but the products obtained by the current process have low purity, which increases the difficulty of subsequent processing, especially the separation and purification of copper and aluminum metals and positive electrode materials, and the separation efficiency is low. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the related art. To this end, the present application proposes a method for applying a physical separation device with multi-modal gradient parallel lines and an integrated system, which can realize efficient separation of all components of waste lithium batteries, and the positive electrode material obtained by separation has high purity.

[0004] The above technical purpose of the present application is realized by the following technical scheme: A method for applying a physical separation device with multi-modal gradient parallel lines and an integrated system, comprising the following steps: (1) cutting and sorting waste lithium batteries to obtain battery shells, separators, electrolytes, positive electrode sheets and negative electrode sheets; (2) crushing the positive electrode sheets and negative electrode sheets, then roasting, and then crushing with an air mill and sieving to obtain materials of different particle sizes; (3) color selecting the sieved materials to separate copper foils and aluminum foils in the form of large particles, and batch-wise air selecting the sieved materials of different particle sizes to obtain copper foils, aluminum foils, positive electrode material mixtures and negative electrode materials; (4) placing the positive electrode material mixtures on different inclined conveyors to separate positive electrode materials and copper and aluminum foils.

[0005] In an embodiment, in step (1), the sorting is performed by using an automatic sorting device.

[0006] In an embodiment, in step (2), the crushed positive electrode sheets and negative electrode sheets are obtained in the form of millimeter-sized particle materials. "Millimeter-sized" refers to particle materials with a particle size greater than 1 millimeter and less than 1000 millimeters.

[0007] In an embodiment, in step (2), the roasting temperature is 200-500 DEG C, and the roasting time is 3-6 h.

[0008] In an embodiment, in step (2), the particle size of the material obtained after the breaking by the jet mill is 100 μm-30 mm.

[0009] In an embodiment, in step (2), the screening is carried out by passing through 30-50 mesh, 100-200 mesh and 300-500 mesh screens in sequence.

[0010] In an embodiment, in step (2), the waste gas generated by the roasting is treated by a waste gas treatment module before being discharged.

[0011] In an embodiment, in step (1), the electrolyte is recovered by negative pressure suction filtration during the cutting and sorting process.

[0012] In an embodiment, in step (4), the inclined conveying belt moves towards the high side, and the inclination angle of the conveying belt is 40-60°.

[0013] In an embodiment, in step (4), the inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size less than 300 mesh is 50-60°, the inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size between 100 mesh and 300 mesh is 45-50°, and the inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size between 30 mesh and 100 mesh is 40-45°. A physical separation device and integrated system for multi-modal gradient laying, comprising: A breaking module comprising a conveyor, a cutting machine, an automatic sorting device, a first shredder and a second jet mill connected in sequence, wherein the waste lithium battery is conveyed to the cutting machine by the conveyor, cut by the cutting machine, sorted by the automatic sorting device, and then the obtained positive electrode sheet and negative electrode sheet are broken by the first shredder and the second jet mill. A pyrolysis module comprising a pyrolysis furnace, wherein the pyrolysis furnace is located between the first shredder and the second jet mill, and the material treated by the first shredder is pyrolyzed by the pyrolysis furnace before being treated by the second jet mill. A sorting module comprising a vibrating sieve, a color sorting device, a cyclone sorting machine and a conveying belt sorting device, wherein the vibrating sieve is used to screen the material broken by the second jet mill, the color sorting device is used to color sort the material on the vibrating sieve to obtain large-grained copper foil and aluminum foil, the cyclone sorting machine is used to air sort the material of different particle sizes in batches, and the conveying belt sorting device is used to sort the positive electrode material mixture obtained by air sorting the material of different particle sizes to obtain positive electrode material and copper-aluminum foil material.

[0014] In an embodiment, a negative pressure suction filtration module is further included, which can recover the electrolyte in the breaking module by negative pressure suction filtration.

[0015] In an embodiment, a waste gas treatment module is further included to treat the waste gas generated by the pyrolysis module.

[0016] The present application has the following advantages: (1) In the present application, the lithium ion battery is cut to separate the upper cover, and the shell, diaphragm, electrolyte, positive and negative electrodes in the five components of the lithium battery are separated to separate the materials of each component of the battery. The positive and negative electrode sheets are pyrolyzed, and the binder is carbonized at a temperature of >200℃, which is conducive to the separation of the battery materials from the electrode sheet.

[0017] (2) In the present application, the pyrolyzed materials are crushed, and the use of airflow mill can separate more than 98% of the battery materials (positive electrode material, negative electrode material) on the electrode sheet.

[0018] (3) In the present application, different particle sizes are separated during screening, and the largest particles in the uppermost layer are large copper-aluminum foils. Further color selection is used to separate the materials of the next step of air separation, and the materials of the same particle size are separated by air separation. By controlling the wind speed during air separation, different density materials can be separated, and the separation effect reaches 98%.

[0019] (4) In the present application, according to the wind strength control of the cyclone, acetylene black, graphite, aluminum foil, positive electrode material mixture and copper foil can be separated in turn.

[0020] (5) In the present application, the positive electrode material mixture obtained by cyclone separation is separated again by using a conveyor belt to improve the purity of the positive electrode material. The copper-aluminum particles in the positive electrode material mixture are sheet-shaped, and the positive electrode material is granular. Therefore, the positive electrode particles can flow downward on the conveyor belt with a certain inclination, but the sheet-shaped copper foil and aluminum foil will not flow and will be collected from the upper port with the running of the conveyor belt, achieving the separation of the positive electrode material and the copper-aluminum foil and further purifying the positive electrode material.

[0021] (6) In the present application, multi-modal physical separation is used: integrating mechanical crushing, vibrating screening, cyclone separation, conveyor belt separation, color selection and other physical modes, covering different material characteristics (such as density, magnetism, particle size), improving the comprehensiveness of separation, and the recovery rate of multi-physical separation combined separation is increased by more than 20% than that of single method.

[0022] (7) In the present application, a gradient and line design is used: the separation process is divided into four levels of gradient: 1. primary separation and solid-liquid separation; 2. intermediate screening and cyclone separation; 3. conveyor belt separation to improve the purity of the positive electrode material and the copper foil. Each stage is connected by material flow to optimize the efficiency, and the conveyor belt separation step can increase the yield of electrode material to more than 85%, solving the problem of low separation efficiency of positive electrode material and copper-aluminum foil, and solving the problem of low efficiency of traditional separation. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A flowchart of the application method of the physical separation device and integrated system of the multi-modal gradient parallel line of embodiment 1 of the present application; Figure 2 A schematic diagram of the physical separation device and integrated system of the multi-modal gradient parallel line of embodiment 1 of the present application. DETAILED DESCRIPTION

[0024] The present application will be further described below in conjunction with specific embodiments.

[0025] Embodiment 1: An application method of a physical separation device and integrated system of a multi-modal gradient parallel line, as shown in Figure 1 , comprising the following steps: (1) The waste lithium ion battery monomer is conveyed to the cutting process through the conveyor, the battery is cut, the automatic sorting equipment is used to separate the battery shell, the diaphragm, the positive plate and the negative plate, and the electrolyte is recovered under negative pressure filtration at 120°C baking; (2) The positive plate and the negative plate are sent into the crushing equipment for crushing to millimeter level particles, the crushed materials are calcined at 350°C for 5h, the binder is carbonized, the calcined materials are crushed by air flow mill, the particle size of the crushed materials is 100μm-30mm, and then the materials are conveyed to the screening machine by the belt, and are screened by 30 mesh, 100 mesh and 300 mesh; (3) The 30 mesh screening material is color selected to separate the copper foil and the aluminum foil in the form of large particles, and the screened materials of different particle sizes are put into the cyclone separator in batches to obtain the copper foil, the aluminum foil, the positive material mixture and the negative material; (4) The positive material mixture is separated by the inclined conveying belt to obtain the positive material and the copper aluminum foil material, the inclination angle of the conveying belt corresponding to the positive material mixture with particle size less than 300 mesh is 55°, the inclination angle of the conveying belt corresponding to the positive material mixture with particle size between 100-300 mesh is 48°, and the inclination angle of the conveying belt corresponding to the positive material mixture with particle size between 30-100 mesh is 42°, the conveying belt is conveyed along the inclination angle, the positive particles can roll down, but the copper foil and the aluminum foil in the form of sheet will not roll, and are collected from the upper port along with the running of the conveying belt, so as to separate the positive material from the copper aluminum foil.

[0026] A physical separation device and integrated system of a multi-modal gradient parallel line, as shown in Figure 2 , comprising: a crushing module, a pyrolysis module, a sorting module, a negative pressure filtration module and a waste gas treatment module; The crushing module comprises conveyors, cutting machines, automatic sorting equipment, a first shredder, and a second jet mill connected in sequence. The waste lithium battery is conveyed to the cutting machine for cutting by the conveyor, and then sorted by the automatic sorting equipment. The obtained positive plate and negative plate are crushed by the first shredder and the second jet mill. The pyrolysis module comprises a pyrolysis furnace between the first shredder and the second jet mill. The material treated by the first shredder is pyrolyzed by the pyrolysis furnace and then enters the second jet mill for treatment. The sorting module comprises a vibrating sieve, a color selection device, a cyclone separator, and a conveyor belt sorting device. The vibrating sieve can screen the material crushed by the second jet mill. The color selection device can color select the material screened by the vibrating sieve to obtain large-granular copper foil and aluminum foil. The cyclone separator can air select the material of different particle sizes in batches. The conveyor belt sorting device can sort the positive material mixture obtained by air selecting the material of different particle sizes to obtain positive material and copper-aluminum foil material. The negative pressure filtration module can recover the electrolyte in the crushing module by negative pressure filtration. The waste gas treatment module can treat the waste gas generated by the pyrolysis module.

[0027] Embodiment 2 A method for applying a multi-modal gradient parallel physical separation device and integrated system, comprising the following steps: (1) conveying the waste lithium ion battery monomer to the cutting process by the conveyor, cutting the battery, separating the battery shell, diaphragm, positive plate, and negative plate by the automatic sorting equipment, and recovering the electrolyte by negative pressure filtration at 150°C baking; (2) sending the positive plate and negative plate to the crushing equipment for crushing to millimeter-level particles, baking the crushed material at 400°C for 5h to carbonize the binder, crushing the baked material by the jet mill, and screening the crushed material with particle sizes of 100μm-30mm by the belt conveyor to the sieve, and screening by 50 mesh, 200 mesh, and 500 mesh; (3) color selecting the 50 mesh sieve material to separate large-granular copper foil and aluminum foil, and feeding the screened material of different particle sizes into the cyclone separator in batches to obtain copper foil, aluminum foil, positive material mixture, and negative material. (4) The positive electrode material mixture is separated by an inclined conveying belt to obtain positive electrode material and copper-aluminum foil material. The inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size less than 500 mesh is 55°, the inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size between 200 mesh and 500 mesh is 48°, and the inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size between 50 mesh and 200 mesh is 42°. The conveying belt is inclined upward along the inclination angle, so that the positive electrode particles roll downward, but the sheet-shaped copper foil and aluminum foil do not roll and are collected from the upper port along with the running of the conveying belt, achieving the effect of separating the positive electrode material from the copper-aluminum foil.

[0028] Example 3 A method for applying a multi-modal gradient parallel physical separation device and integrated system, comprising the following steps: (1) The waste lithium ion battery monomer is conveyed to the cutting process by the conveyor, the battery is cut, the automatic sorting equipment is used to separate the battery shell, the diaphragm, the positive electrode sheet and the negative electrode sheet, and the electrolyte is recovered by negative pressure filtration under 100°C baking; (2) The positive electrode sheet and the negative electrode sheet are sent into the crushing equipment for crushing to millimeter-level particles. The crushed material is calcined at 450°C for 5h to carbonize the binder. The calcined material is crushed by an air flow mill, and the particle size of the crushed material is 100μm-30mm. The material is then conveyed to a screening machine by a belt, and is screened by 50 mesh, 200 mesh and 500 mesh; (3) The 50 mesh screened material is color sorted to separate copper foil and aluminum foil in the form of large particles. The screened materials of different particle sizes are fed into a cyclone separator in batches to obtain copper foil, aluminum foil, positive electrode material mixture and negative electrode material; (4) The positive electrode material mixture is separated by an inclined conveying belt to obtain positive electrode material and copper-aluminum foil material. The inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size less than 500 mesh is 55°, the inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size between 200 mesh and 500 mesh is 48°, and the inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size between 50 mesh and 200 mesh is 42°. The conveying belt is inclined upward along the inclination angle, so that the positive electrode particles roll downward, but the sheet-shaped copper foil and aluminum foil do not roll and are collected from the upper port along with the running of the conveying belt, achieving the effect of separating the positive electrode material from the copper-aluminum foil.

[0029] Example 4 A method for applying a multi-modal gradient parallel physical separation device and integrated system, comprising the following steps: (1) The waste lithium ion battery monomer is conveyed to the cutting process by the conveyor, the battery is cut, the automatic sorting equipment is used to separate the battery shell, the diaphragm, the positive electrode sheet and the negative electrode sheet, and the electrolyte is recovered by negative pressure filtration under 120°C baking; (2) The positive electrode sheet and the negative electrode sheet are sent into a crushing device for crushing, and are crushed to millimeter-level particles. The crushed materials are calcined at 400 DEG C for 5h, the binder is carbonized, and the calcined materials are crushed by using an air flow mill. The particle size of the crushed materials is between 100pm and 30mm. Then, the materials are transmitted to a screening machine by using a belt, and are screened by using 30 mesh, 100 mesh and 300 mesh; (3) The materials on the 30 mesh screen are color-selected, and large-granular copper foil and aluminum foil are separated. The materials of different particle sizes after screening are fed into a cyclone separator in batches, and copper foil, aluminum foil, positive electrode material mixture and negative electrode material are obtained. (4) The positive electrode material mixture is separated by an inclined conveying belt to obtain positive electrode material and copper-aluminum foil material. The inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size less than 300 mesh is 55 DEG. The inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size between 100 mesh and 300 mesh is 48 DEG. The inclination angle of the conveying belt corresponding to the positive electrode material mixture with a particle size between 30 mesh and 100 mesh is 42 DEG. The conveying belt is conveyed along the inclination angle, so that the positive electrode particles roll downward, but the copper foil and the aluminum foil in sheet form do not roll and are collected from the upper port along with the running of the conveying belt, thereby achieving the separation of the positive electrode material and the copper-aluminum foil.

[0030] Comparative Example 1 A waste lithium battery crushing and sorting method comprises the following steps: The waste lithium ion battery monomer is sent into a crusher, and is coarsely broken under a nitrogen protection atmosphere. The particle size after coarse breaking is between 10mm and 30mm. After separating the electrolyte at 140 DEG C, the shell and the diaphragm are separated manually. Then, the remaining materials are calcined at 400 DEG C for 5h. The calcined materials are separated in a 120 mesh vibrating screen to separate the copper-aluminum foil and the black powder.

[0031] Comparative Example 2 A waste lithium battery crushing and sorting method comprises the following steps: The waste lithium ion battery monomer is sent into a crusher, and is coarsely broken under a nitrogen protection atmosphere. The particle size after coarse breaking is between 10mm and 30mm. After separating the electrolyte at 140 DEG C, the shell and the diaphragm are separated manually. Then, the remaining materials are calcined at 350 DEG C for 5h. The calcined materials are separated by a cyclone separator to separate the copper-aluminum foil and the black powder.

[0032] Comparative Example 3 A waste lithium battery crushing and sorting method comprises the following steps: The waste lithium ion battery monomer is sent into a crusher, and is coarsely broken under a nitrogen protection atmosphere, the particle size after coarse breaking is 10-30mm, the electrolyte is separated at 140 DEG C, then the shell and the diaphragm are manually separated, the remaining material is calcined at 350 DEG C for 5h, and the material is finely ground to be less than 5mm through combination of cyclone separation and fine grinding, and the copper foil and the black powder are separated through combination of cyclone separation and fine grinding.

[0033] Test example: The particle size, impurity content in the copper foil, copper and aluminum content in the positive electrode material and positive electrode material recovery rate of all the positive electrode materials obtained by the method of testing examples 1-4 and comparative examples 1-3 are tested respectively, and the results are shown in the following table 1.

[0034] Table 1.

[0035] As shown in table 1, the positive electrode material obtained by the application method of the multi-modal gradient parallel line physical separation device and integrated system has a smaller particle size, the impurity content in the copper foil is less than 1.6%, the copper and aluminum content in the positive electrode material is less than 0.48%, and the positive electrode material recovery rate is more than 98.6%.

Claims

1. A physical separation device and integrated system for multimodal gradient parallel lines, characterized in that: Includes the following steps: (1) Cut and sort the waste lithium batteries to obtain the battery casing, separator, electrolyte, positive electrode and negative electrode; (2) The positive electrode and negative electrode are crushed and then roasted, and then crushed by air jet mill and screened to obtain materials of different particle sizes; (3) Color sorting is performed on the material on the sieve to separate large-particle copper foil and aluminum foil. The materials of different particle sizes after screening are air sorted in batches to obtain copper foil, aluminum foil, positive electrode material mixture and negative electrode material. (4) The positive electrode material mixture is placed on conveyor belts with different inclinations for sorting to obtain positive electrode material and copper-aluminum foil.

2. The application method of the physical separation device and integrated system for multimodal gradient parallel lines according to claim 1, characterized in that: In step (1), the sorting is carried out using an automated sorting device.

3. The application method of the physical separation device and integrated system for multimodal gradient parallel lines according to claim 1, characterized in that: In step (2), the positive electrode and the negative electrode are crushed to obtain millimeter-sized granular materials.

4. The application method of the physical separation device and integrated system for multimodal gradient parallel lines according to claim 1, characterized in that: In step (2), the roasting temperature is 200-500℃ and the roasting time is 3-6h.

5. The application method of the physical separation device and integrated system for multimodal gradient parallel lines according to claim 1, characterized in that: In step (2), the particle size of the material obtained after crushing by air jet mill is between 100μm and 30mm.

6. The application method of the physical separation device and integrated system for multimodal gradient parallel lines according to claim 1, characterized in that: In step (2), the sieving is performed by sequentially passing the material through a 30-50 mesh sieve, a 100-200 mesh sieve, and a 300-500 mesh sieve.

7. The application method of the physical separation device and integrated system for multimodal gradient parallel lines according to claim 1, characterized in that: In step (2), the exhaust gas generated during roasting is treated by the exhaust gas treatment module before being discharged.

8. The application method of the physical separation device and integrated system for multimodal gradient parallel lines according to claim 1, characterized in that: In step (4), the inclined conveyor belt moves toward the higher side, and the inclination angle of the conveyor belt is 40-60°.

9. The application method of the physical separation device and integrated system for multimodal gradient parallel lines according to claim 8, characterized in that: In step (4), the conveyor belt tilt angle for the positive electrode material mixture with a particle size of less than 300 mesh is 50-60°, the conveyor belt tilt angle for the positive electrode material mixture with a particle size between 100-300 mesh is 45-50°, and the conveyor belt tilt angle for the positive electrode material mixture with a particle size between 30-100 mesh is 40-45°.

10. A physical separation device and integrated system for multimodal gradient parallel lines, characterized in that: include: The crushing module includes a conveyor, a cutter, an automatic sorting device, a primary shredder, and a secondary air jet mill connected in sequence. Waste lithium batteries are conveyed by the conveyor to the cutter for cutting, then sorted by the automatic sorting device, and the resulting positive and negative electrode sheets are crushed by the primary shredder and the secondary air jet mill. The pyrolysis module includes a pyrolysis furnace, which is located between the primary shredder and the secondary air jet mill. The material processed by the primary shredder is pyrolyzed in the pyrolysis furnace and then enters the secondary air jet mill for further processing. The sorting module includes a vibrating screen, a color sorter, a cyclone separator, and a conveyor belt sorting device. The vibrating screen screens the material crushed by the secondary air jet mill. The color sorter sorts the material on the screen of the vibrating screen to obtain large-particle copper foil and aluminum foil. The cyclone separator sorts the material of different particle sizes in batches after screening. The conveyor belt sorting device sorts the positive electrode material mixture obtained by sorting the material of different particle sizes in batches to obtain positive electrode material and copper-aluminum foil.

Images