A process for crushing and sorting retired lithium-ion batteries

Abstract

This invention discloses a process for crushing and sorting retired lithium-ion batteries, comprising: primary crushing of retired lithium-ion batteries that have not undergone discharge treatment to obtain coarse crushed material and coarse crushed dust-laden exhaust gas; drying the coarse crushed material at a set temperature to obtain dried material and dried exhaust gas; secondary crushing of the dried material, followed by primary screening to obtain primary undersize material, primary oversize material, and primary dust-laden exhaust gas; air classification of the primary oversize material to obtain the casing of the retired lithium-ion battery, primary electrode material, and air-classified dust-laden exhaust gas; tertiary crushing of the primary electrode material to obtain the casing of the retired lithium-ion battery, secondary electrode material, and secondary dust-laden exhaust gas; pulverizing the primary undersize material and secondary electrode material, followed by secondary screening to obtain a copper-aluminum electrode mixture, black powder, and tertiary dust-laden exhaust gas. The technical solution of this invention is simple, requires few equipment, and has a high product recovery rate.

Description

Technical Field

[0001] This invention relates to the field of lithium battery recycling technology, and in particular to a crushing and sorting process for retired lithium-ion batteries. Background Technology

[0002] As lithium-ion batteries become increasingly widely used, the number of retired lithium-ion batteries is also increasing as they reach the end of their service life. Recycling the non-renewable resources from retired lithium-ion batteries is of great significance for resource conservation and reducing battery production costs.

[0003] However, existing processes for crushing and sorting retired lithium-ion batteries typically include steps such as coarse crushing, electrolyte drying, fine crushing, sieving, and air classification of the casing and separator. The positive and negative electrode mixture obtained after air classification is then crushed and sieved to obtain black powder and copper-aluminum particles. This process has the following problems: 1. Lithium-ion batteries are prone to catching fire when crushed, requiring discharge before crushing; 2. Due to the performance limitations of the air classifier, the recovery rate and quality of the casing and separator are low; 3. In the crushing and sieving process, the positive and negative electrode mixture often contains too much casing (aluminum shell) and separator (rigid plastic), resulting in poor processing effect and excessively high Al and Cu impurity content in the black powder. Therefore, a multi-stage crushing-multi-stage sieving process is required, necessitating a large amount of equipment and energy consumption. Summary of the Invention

[0004] This invention provides a process for crushing and sorting retired lithium-ion batteries to overcome the shortcomings of existing technologies, improve product recovery rate, reduce the number of equipment, and simplify the process.

[0005] On one hand, the present invention provides a process for crushing and sorting retired lithium-ion batteries, comprising:

[0006] The retired lithium-ion batteries that have not undergone discharge treatment are crushed once to obtain coarse crushed material and coarse crushed dust-containing exhaust gas.

[0007] The coarsely crushed material is dried at a set temperature to obtain dried material and drying exhaust gas;

[0008] The dried material is subjected to secondary crushing, and the material after secondary crushing is subjected to primary screening to obtain primary undersize material, primary oversize material and primary dust-containing exhaust gas.

[0009] The material on the primary sieve is subjected to air separation to obtain the casing of the retired lithium-ion battery, primary electrode material, and dust-laden exhaust gas from air separation.

[0010] The primary electrode material is crushed three times to obtain the casing of the retired lithium-ion battery, the secondary electrode material, and the secondary dust-containing waste gas.

[0011] The primary undersize material and the secondary electrode material are pulverized and powdered, and the pulverized material is then subjected to secondary sieving to obtain a copper-aluminum electrode mixture, black powder, and tertiary dust-containing waste gas.

[0012] Optionally, the decommissioned lithium-ion battery crushing and sorting process further includes:

[0013] The coarse crushed dust-laden exhaust gas, the primary dust-laden exhaust gas, the air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas are transported to a dust collection device for dust-gas separation.

[0014] Optionally, the dust collection device includes a first dust collector, a second dust collector, and a third dust collector;

[0015] The coarse crushed dust-laden exhaust gas, the primary dust-laden exhaust gas, the air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas are transported to a dust collection device for dust-gas separation, including:

[0016] The coarse crushing dust-laden exhaust gas is transported to the first dust collector, and dust is collected by the first dust collector to separate the black powder and exhaust gas in the coarse crushing dust-laden exhaust gas;

[0017] The primary dust-laden exhaust gas is transported to the second dust collector, where dust is collected to obtain primary dust and exhaust gas.

[0018] The air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas are transported to a third dust collector, where dust is collected to obtain the black powder and exhaust gas in the air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas.

[0019] Optionally, the decommissioned lithium-ion battery crushing and sorting process further includes:

[0020] The primary dust is conveyed to the first screening device so that the first screening device can screen the primary dust to obtain a diaphragm and black powder.

[0021] Optionally, the decommissioned lithium-ion battery crushing and sorting process further includes:

[0022] The copper-aluminum electrode mixture is subjected to gravity separation to obtain copper particles, aluminum particles, and separated dust-containing waste gas.

[0023] Optionally, the retired lithium-ion batteries that have not been discharged are subjected to charged crushing to obtain coarsely crushed material, including:

[0024] The retired lithium-ion batteries that have not been discharged are fed to a primary crusher, where they are shredded under preset conditions to obtain coarse crushed material. The particle size of the coarse crushed material is less than 40 mm. The preset conditions include: the oxygen content inside the crusher is less than a preset oxygen content, and the organic gas content inside the crusher is less than a preset organic gas content.

[0025] Optionally, the coarsely crushed material is dried at a set temperature to obtain dried material, including:

[0026] The coarsely crushed material is conveyed to a rotary kiln, so that the rotary kiln dries the coarsely crushed material at a set temperature; the set temperature ranges from 100℃ to 200℃.

[0027] Optionally, the dried material is subjected to secondary crushing, and the material after secondary crushing is subjected to primary screening to obtain primary undersize material, primary oversize material, and primary dust-containing exhaust gas, including:

[0028] The dried material is conveyed to a secondary crusher, whereby the secondary crusher shears and finely crushes the dried material to obtain finely crushed material; the particle size of the finely crushed material is less than 20 mm.

[0029] The finely crushed material is conveyed to a second screening device, which performs primary screening on the finely crushed material to obtain primary undersize material, primary oversize material, and primary dust-laden exhaust gas; the particle size of the primary undersize material is less than 4 mm; the particle size of the primary oversize material is greater than or equal to 4 mm.

[0030] Optionally, the primary electrode material is crushed three times to obtain the casing of the retired lithium-ion battery, secondary electrode material, and secondary dust-laden waste gas, including:

[0031] The primary electrode material is conveyed to a flexible crushing device, which then performs flexible crushing of the primary electrode material to obtain the casing of the retired lithium-ion battery, the secondary electrode material, and the secondary dust-laden exhaust gas. The flexible crushing device includes a rod mill system and a drum screen, with the rod mill system disposed in the drum of the drum screen. The particle size of the secondary electrode material is less than or equal to 4 mm.

[0032] Optionally, the retired lithium-ion battery crushing and sorting process further includes: transporting the waste gas to a tail gas treatment device for tail gas treatment.

[0033] The technical solution of this invention involves first crushing retired lithium-ion batteries that have not undergone discharge treatment to obtain coarsely crushed material and coarsely crushed dust-laden exhaust gas. The coarsely crushed material is then dried at a set temperature to obtain dried material and dried exhaust gas. The dried material is then subjected to a second crushing, followed by primary screening to obtain primary undersize material, primary oversize material, and primary dust-laden exhaust gas. The primary oversize material is then air-classified to obtain the retired lithium-ion battery casing, primary electrode material, and air-classified dust-laden exhaust gas. The primary electrode material is then crushed a third time to obtain the retired lithium-ion battery casing, secondary electrode material, and secondary dust-laden exhaust gas. Finally, the primary undersize material and secondary electrode material are pulverized into powder. The pulverized material undergoes secondary screening to obtain a mixture of copper and aluminum electrodes, black powder, and tertiary dust-laden exhaust gas. This allows retired lithium-ion batteries to be crushed in one stage without prior discharge, requiring only four stages of crushing and two stages of screening. Compared to existing methods involving charged crushing, five stages of crushing, and three stages of screening, this reduces the process flow and the number of equipment. Furthermore, the material under the primary screen does not require air classification and tertiary crushing, reducing the equipment's throughput. Since the material under the primary screen does not contain the outer shell or separator, it can be directly pulverized, thereby limiting the recovery index of black powder and reducing impurities such as copper and aluminum. At the same time, the material over the primary screen has a uniform particle size, which can reduce the throughput of air classification equipment and improve the quality of the outer shell product.

[0034] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a process flow diagram of a decommissioned lithium-ion battery crushing and sorting process provided in Embodiment 1 of the present invention;

[0037] Figure 2 This is a process flow diagram of a decommissioned lithium-ion battery crushing and sorting process provided in Embodiment 2 of the present invention;

[0038] Figure 3 This is a process flow diagram of a decommissioned lithium-ion battery crushing and sorting process provided in Embodiment 3 of the present invention;

[0039] Figure 4 A flowchart of the decommissioned lithium-ion battery crushing and sorting process provided in an embodiment of the present invention. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0042] Example 1

[0043] This invention provides a process for crushing and sorting retired lithium-ion batteries. Figure 1 This invention provides a process flow diagram for the crushing and sorting of retired lithium-ion batteries, as part of an embodiment of the present invention. (Reference) Figure 1 As shown, the decommissioned lithium-ion battery crushing and sorting process provided in this embodiment of the invention includes:

[0044] S1. The retired lithium-ion batteries that have not undergone discharge treatment are crushed once to obtain coarse crushed material and coarse crushed dust-containing waste gas.

[0045] The retired lithium-ion batteries may include retired lithium-ion battery cells smaller than 500mm. Primary crushing can be carried out in a primary crushing device; the primary crushing device can be a crusher, and in an exemplary embodiment, the primary crushing device includes a bi-shaft shredder.

[0046] In one exemplary embodiment, retired lithium-ion batteries do not require discharge and are directly conveyed to a crusher via a belt for primary crushing. During this primary crushing process, the retired lithium-ion batteries are shredded by the crusher's blades, completing the individual cell separation and yielding coarsely crushed material and coarsely crushed dust-laden exhaust gas. To ensure the safe crushing of retired lithium-ion batteries that have not undergone discharge treatment and prevent fire, a protective gas must be introduced throughout the primary crushing process; for example, nitrogen is introduced, and an external fan is used to promptly draw the electrolyte volatilized during the primary crushing process to the exhaust gas treatment device for combustion.

[0047] In one optional embodiment, retired lithium-ion batteries that have not been discharged are subjected to charged crushing to obtain coarsely crushed material, including:

[0048] Undischarged retired lithium-ion batteries are fed to a primary crusher, where they are shredded under preset conditions to obtain coarse crushed material.

[0049] The primary crusher includes a dual-shaft shredder, which shreds retired lithium-ion batteries that have not undergone discharge treatment to obtain coarsely crushed material. In an exemplary embodiment, the particle size of the coarsely crushed material is less than 40mm, thus ensuring uniform heating and drying during subsequent drying processes. Preset conditions include that the oxygen content inside the crusher is less than a preset oxygen content, and the organic gas content inside the crusher is less than a preset organic gas content. The preset oxygen content can be set to be less than the minimum oxygen content required for combustion; in an exemplary embodiment, this preset oxygen content can be 5%. The preset organic gas content can be set to be lower than the minimum organic gas content required for organic gas combustion; in an exemplary embodiment, this preset organic gas content can be 120mg / m³. In an optional embodiment, the crushing chamber of the primary crusher is equipped with an oxygen detector and an organic gas detector. This allows the oxygen content inside the crusher to be detected by the oxygen detector, thereby controlling the oxygen content to be less than the preset oxygen content. Simultaneously, the organic gas detector detects the organic gas content inside the crusher, thereby controlling the organic gas content to be less than the preset organic gas content.

[0050] S2. Dry the coarsely crushed material at a set temperature to obtain dried material and drying exhaust gas.

[0051] The set temperature can be determined based on the thermal properties of residual electrolyte and separator materials in the coarsely crushed material. The set temperature should not be too high to prevent thermal decomposition of the separator and binder, which would reduce the recycling rate of retired lithium-ion batteries. Simultaneously, the set temperature should not be too low to prevent incomplete electrolyte evaporation. During the drying process of the coarsely crushed material, the residual electrolyte after the initial crushing evaporates as fluorides and organic gases, forming drying exhaust gas. In an exemplary embodiment, the drying exhaust gas is drawn into a tail gas treatment device for combustion. The remaining material after drying the coarsely crushed material is the dried material.

[0052] In one optional embodiment, drying the coarsely crushed material at a set temperature to obtain dried material includes: conveying the coarsely crushed material to a rotary kiln so that the rotary kiln lowers the temperature to dry the coarsely crushed material at the set temperature.

[0053] The set temperature range is 100℃-200℃. When the set temperature is below 100℃, some electrolyte may not evaporate, resulting in incomplete electrolyte evaporation. When the set temperature is above 200℃, materials such as separators and binders in the coarsely crushed materials are easily thermally decomposed, affecting the recycling rate of retired lithium-ion batteries.

[0054] S3. The dried material is subjected to secondary crushing, and the material after secondary crushing is subjected to primary screening to obtain primary undersize material, primary oversize material and primary dust-containing exhaust gas.

[0055] The secondary crushing of dried materials involves conveying them to a crushing device for further crushing, reducing the particle size to meet the requirements of subsequent air classification. It's important to note that this crushing device differs from the primary crushing device; the particle size of the material after secondary crushing is smaller than that of the coarsely crushed material. Primary screening can be performed in a screening device, for example, a 4mm single-layer vibrating screen. In this case, the particle size of the material passing through the primary screen is less than 4mm, while the particle size of the material passing through the primary screen is greater than or equal to 4mm. It is understood that when the screen aperture of the screening device is other sizes, the sizes of the material passing through and passing through the primary screen will also change accordingly.

[0056] Specifically, the coarsely crushed material is conveyed to the drying device and dried at a set temperature to obtain dried material. Then, the dried material is conveyed to the crushing device for secondary crushing to reduce the particle size of the dried material. The material after secondary crushing is conveyed to the screening equipment to screen the material to obtain primary undersize material, primary oversize material and primary dust-containing waste gas. The primary undersize material is directly crushed and pulverized.

[0057] In one optional embodiment, the dried material is subjected to secondary crushing, and the material after secondary crushing is subjected to primary screening to obtain primary undersize material, primary oversize material, and primary dust-containing exhaust gas. This includes: conveying the dried material to a secondary crusher so that the secondary crusher shears and finely crushes the dried material to obtain finely crushed material; and conveying the finely crushed material to a second screening device so that the second screening device performs primary screening to obtain primary undersize material, primary oversize material, and primary dust-containing exhaust gas.

[0058] The secondary crusher can further crush the dried material to obtain finely crushed material. The particle size of the finely crushed material is smaller than that of the coarsely crushed material, thus meeting the particle size requirements of the subsequent air classification process. For example, the particle size of the finely crushed material is less than 20 mm. The second screening equipment may include a vibrating screen. After primary screening by the vibrating screen, the finely crushed material is divided into primary undersize material and primary oversize material. The particle size of the primary undersize material is less than 4 mm, accounting for approximately 50% of the finely crushed material, and the particle size of the primary oversize material is greater than or equal to 4 mm, accounting for approximately 40% of the finely crushed material. For example, the second screening equipment includes a 4 mm single-layer vibrating screen.

[0059] S4. The material on the primary screen is air-separated to obtain the casing of the retired lithium-ion battery, the primary electrode material, and the dust-laden exhaust gas from the air separation.

[0060] The process of air-separating the material over the primary screen can be achieved by conveying the material over the primary screen to an air separator, which then separates the material over the primary screen to obtain the casing of retired lithium-ion batteries, primary electrode material, and dust-laden exhaust gas. The casing of retired lithium-ion batteries is the casing blown out by the air separator, the primary electrode material is the remaining material after the air separator, and the dust-laden exhaust gas is the extracted exhaust gas containing black powder and waste gas.

[0061] S5. The primary electrode material is crushed three times to obtain the casing of the retired lithium-ion battery, the secondary electrode material, and the secondary dust-containing waste gas.

[0062] The primary electrode material undergoes a three-stage crushing process. This involves feeding the primary electrode material to a crushing device, where it is further crushed to reduce its particle size, resulting in secondary electrode material that meets the particle size requirements of subsequent pulverization processes. It should be noted that this crushing device differs from the aforementioned primary and secondary crushing devices. The secondary electrode material after the three-stage crushing process has a smaller particle size than the material after the two-stage crushing. After the primary electrode material undergoes three screenings, the resulting waste lithium-ion battery casing and secondary dust-laden exhaust gas are also obtained. In an optional embodiment, the primary electrode material can be screened simultaneously during the three-stage crushing process to further separate the waste lithium-ion battery casing and secondary electrode material.

[0063] In one optional embodiment, the primary electrode material is crushed three times to obtain the casing of the retired lithium-ion battery, the secondary electrode material, and the secondary dust-laden exhaust gas. This includes: conveying the primary electrode material to a flexible crushing device so that the flexible crushing device can flexibly crush the primary electrode material to obtain the casing of the retired lithium-ion battery, the secondary electrode material, and the secondary dust-laden exhaust gas.

[0064] The flexible crushing device includes a rod mill system and a drum screen. The rod mill system is installed in the drum of the drum screen, so that the primary electrode material can be selectively crushed after being ground and impacted by the rod mill system. That is, the electrode material in the primary electrode material is crushed into smaller particles, while the outer shell of the primary electrode material retains its intact shape. Thus, after being screened by the drum screen, the shell of the retired lithium-ion battery, the secondary electrode material, and the secondary dust-containing waste gas are obtained. The particle size of the secondary electrode material is smaller than that of the fine crushed material. For example, the particle size of the secondary electrode material is less than or equal to 4 mm.

[0065] S6. The material undersized from the first-stage sieve and the material undersized from the second-stage electrode are pulverized and then subjected to a second-stage sieve to obtain a mixture of copper and aluminum electrodes, black powder, and tertiary dust-laden exhaust gas.

[0066] The process of pulverizing the primary undersize material and the secondary electrode material involves mixing the primary undersize material and the secondary electrode material and then feeding them into a pulverizer. The pulverizer's blades strike the electrode material, causing the copper and aluminum electrodes to separate from the black powder adhering to them. The separated material is then fed into a secondary screening device for secondary screening, thereby recovering the copper and aluminum electrode mixture and the black powder separately. The tertiary dust-containing waste gas is the dust-containing waste gas generated during the pulverizing and secondary screening processes, which contains black powder and waste gas.

[0067] Specifically, the material oversize from the primary screening is conveyed to an air classifier for air separation, yielding the casings of retired lithium-ion batteries, primary electrode material, and dust-laden exhaust gas. The casings of retired lithium-ion batteries are recycled as the final casing product. The primary electrode material is conveyed to a crushing device for tertiary crushing, yielding the casings of retired lithium-ion batteries, secondary electrode material, and secondary dust-laden exhaust gas. The casings of retired lithium-ion batteries are recycled as the final casing product. The secondary electrode material is mixed with the material undersize from the primary screening and then conveyed to a pulverizer for grinding and powdering to separate the copper-aluminum electrodes from the black powder adhering to them. The separated material is conveyed to a screening device for secondary screening, yielding a mixture of copper-aluminum electrodes, black powder, and tertiary dust-laden exhaust gas. The resulting black powder is recycled as the final black powder product.

[0068] In this embodiment, retired lithium-ion batteries that have not undergone discharge treatment are first crushed to obtain coarse crushed material and coarse crushed dust-laden exhaust gas. The coarse crushed material is then dried at a set temperature to obtain dried material and drying exhaust gas. The dried material is then crushed a second time, and the crushed material is subjected to primary screening to obtain primary undersize material, primary oversize material, and primary dust-laden exhaust gas. The primary oversize material is then air-classified to obtain the casing of the retired lithium-ion battery, primary electrode material, and air-classified dust-laden exhaust gas. The primary electrode material is then crushed a third time to obtain the casing of the retired lithium-ion battery, secondary electrode material, and secondary dust-laden exhaust gas. The primary undersize material and secondary electrode material are then pulverized and powdered, and the pulverized and powdered material is subjected to secondary screening. This process yields a mixture of copper and aluminum electrodes, black powder, and three stages of dust-laden exhaust gas. This allows retired lithium-ion batteries to be crushed in one stage without prior discharge, requiring only four stages of crushing and two stages of screening. Compared to existing methods involving charged crushing, five stages of crushing, and three stages of screening, this reduces the number of processes and equipment. Furthermore, the material under the first stage screen does not require air classification or three stages of crushing, reducing the equipment's throughput. Since the material under the first stage screen does not contain the outer shell or separator, it can be directly crushed and powdered, thereby improving the recovery index of black powder and reducing impurities such as copper and aluminum. At the same time, the material over the first stage screen has uniform particle size, which can reduce the throughput of air classification equipment, improve the quality of the outer shell product, and achieve a recovery rate of over 98% and a grade of over 99% for the outer shell product.

[0069] Example 2

[0070] Figure 2 This is a process flow diagram of a decommissioned lithium-ion battery crushing and sorting process provided in Embodiment 2 of the present invention. Based on the above embodiments, this embodiment further adds steps for copper-aluminum electrode separation and dust-gas separation. (Refer to...) Figure 2 As shown, the specific processes for crushing and sorting retired lithium-ion batteries include:

[0071] S1. The retired lithium-ion batteries that have not undergone discharge treatment are crushed once to obtain coarse crushed material and coarse crushed dust-containing waste gas.

[0072] S2. Dry the coarsely crushed material at a set temperature to obtain dried material and drying exhaust gas.

[0073] S3. The dried material is subjected to secondary crushing, and the material after secondary crushing is subjected to primary screening to obtain primary undersize material, primary oversize material and primary dust-containing exhaust gas.

[0074] S4. The material on the primary screen is air-separated to obtain the casing of the retired lithium-ion battery, the primary electrode material, and the dust-laden exhaust gas from the air separation.

[0075] S5. The primary electrode material is crushed three times to obtain the casing of the retired lithium-ion battery, the secondary electrode material, and the secondary dust-containing waste gas.

[0076] S6. The material undersized from the first-stage sieve and the material undersized from the second-stage electrode are pulverized and then subjected to a second-stage sieve to obtain a mixture of copper and aluminum electrodes, black powder, and tertiary dust-laden exhaust gas.

[0077] S7. The copper-aluminum electrode mixture is subjected to gravity separation to obtain copper particles, aluminum particles and separated dust-containing waste gas.

[0078] Specifically, by gravity separation, copper particles and aluminum particles in a copper-aluminum mixture are separated. The copper particles are recovered as the final copper particles, and the aluminum particles are recovered as the final aluminum particles, thereby improving the recovery rate of both copper and aluminum particles. In an exemplary embodiment, reference is made to... Figure 2 As shown, the black powder and waste gas in the sorted dusty waste gas can be obtained by conveying the sorted dusty waste gas to the third dust collector and collecting the dust through the third dust collector, thereby improving the recovery rate of black powder.

[0079] S8. The coarse crushed dust-laden waste gas, primary dust-laden waste gas, air-separated dust-laden waste gas, secondary dust-laden waste gas, and tertiary dust-laden waste gas are transported to the dust collection device for dust-gas separation.

[0080] The dust collection device may include, but is not limited to, baghouse dust collectors and cyclone dust collectors. Since the coarse crushing dust-laden exhaust gas, primary dust-laden exhaust gas, air-classified dust-laden exhaust gas, secondary dust-laden exhaust gas, and tertiary dust-laden exhaust gas all contain black powder and exhaust gas, by conveying the coarse crushing dust-laden exhaust gas, primary dust-laden exhaust gas, air-classified dust-laden exhaust gas, secondary dust-laden exhaust gas, and tertiary dust-laden exhaust gas to the dust collection device, the black powder and exhaust gas can be separated to further recover the black powder and improve the black powder recovery rate. In this way, the black powder recovery rate is greater than 98%, and the aluminum impurity content and copper impurity content in the recovered black powder are less than 0.5% and less than 0.5%, respectively.

[0081] In this embodiment, by gravity separation of copper and aluminum electrode sheets, copper particles, aluminum particles, and separated dust-laden exhaust gas are obtained, thereby separating the copper particles from the aluminum mixture. The copper particles are then recycled as the final copper particles, and the aluminum particles are recycled as the final aluminum particles, thus improving the recovery rate of copper and aluminum particles. By transporting the coarse crushed dust-laden exhaust gas, primary dust-laden exhaust gas, air-classified dust-laden exhaust gas, secondary dust-laden exhaust gas, and tertiary dust-laden exhaust gas to the dust collection device for dust-gas separation, the black powder in the dust-laden exhaust gas can be separated from the exhaust gas, thereby further recovering the black powder and improving the black powder recovery rate.

[0082] Example 3

[0083] Figure 3 This is a process flow diagram of a decommissioned lithium-ion battery crushing and sorting process provided in Embodiment 3 of the present invention. This embodiment further adds a dust collection device, including a first dust collector, a second dust collector, and a third dust collector, based on the above embodiments, and describes the steps of how to use the dust collection device for dust-gas separation. (Refer to...) Figure 3 As shown, the specific processes for crushing and sorting retired lithium-ion batteries include:

[0084] S1. The retired lithium-ion batteries that have not undergone discharge treatment are crushed once to obtain coarse crushed material and coarse crushed dust-containing waste gas.

[0085] S2. Dry the coarsely crushed material at a set temperature to obtain dried material and drying exhaust gas.

[0086] S3. The dried material is subjected to secondary crushing, and the material after secondary crushing is subjected to primary screening to obtain primary undersize material, primary oversize material and primary dust-containing exhaust gas.

[0087] S4. The material on the primary screen is air-separated to obtain the casing of the retired lithium-ion battery, the primary electrode material, and the dust-laden exhaust gas from the air separation.

[0088] S5. The primary electrode material is crushed three times to obtain the casing of the retired lithium-ion battery, the secondary electrode material, and the secondary dust-containing waste gas.

[0089] S6. The material undersized from the first-stage sieve and the material undersized from the second-stage electrode are pulverized and then subjected to a second-stage sieve to obtain a mixture of copper and aluminum electrodes, black powder, and tertiary dust-laden exhaust gas.

[0090] S7. The copper-aluminum electrode mixture is subjected to gravity separation to obtain copper particles, aluminum particles and separated dust-containing waste gas.

[0091] S811. The coarse crushing dust-laden exhaust gas is transported to the first dust collector, and dust is collected by the first dust collector to separate the black powder and exhaust gas in the coarse crushing dust-laden exhaust gas.

[0092] The first dust collector may include, but is not limited to, a bag filter and a cyclone dust collector. In an exemplary embodiment, the first dust collector includes a cyclone dust collector. After the coarsely crushed dust-laden exhaust gas is collected by the first dust collector, black powder and exhaust gas are obtained. The black powder is recycled as the final black powder product, and the exhaust gas can be discharged after tail gas treatment.

[0093] S821. The primary dust-laden exhaust gas is transported to the second dust collector, and dust is collected by the second dust collector to obtain primary dust and exhaust gas.

[0094] The second dust collector may include, but is not limited to, bag filters and cyclone dust collectors. In an exemplary embodiment, the second dust collector may include a bag filter. After the primary dust-laden exhaust gas is collected by the second dust collector, primary dust and exhaust gas are obtained. The exhaust gas can be discharged after tail gas treatment.

[0095] S822. The primary dust is conveyed to the first screening device so that the first screening device can screen the primary dust to obtain diaphragm and black powder.

[0096] The first screening device can be a drum screen. After the primary dust is conveyed to the first screening device for screening, the material on the screen is the diaphragm, and the material under the screen is black powder. The diaphragm is recycled as the final diaphragm product, so that the diaphragm recovery rate is greater than 98% and the grade of the diaphragm product is greater than 99%. The black powder is recycled as the final black powder product.

[0097] S831. The air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas are transported to the third dust collector, and dust is collected by the third dust collector to obtain the black powder and exhaust gas in the air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas.

[0098] The third dust collector may include, but is not limited to, bag filters and cyclone dust collectors. In an exemplary embodiment, the third dust collector may include a bag filter. After the air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas are collected by the third dust collector, black powder and exhaust gas are obtained from the air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas. The black powder is recovered as the final black powder product, and the exhaust gas can be discharged after tail gas treatment.

[0099] In one optional embodiment, the exhaust gas after dust and gas separation is sent to the exhaust gas treatment device for exhaust gas treatment to meet emission standards.

[0100] In this embodiment, the dust collection device includes a first dust collector, a second dust collector, and a third dust collector. The coarsely crushed dust-laden exhaust gas is transported to the first dust collector for dust collection, separating the black powder and exhaust gas from the coarsely crushed dust-laden exhaust gas. The first-stage dust-laden exhaust gas is transported to the second dust collector for dust collection, obtaining first-stage dust and exhaust gas. The air-classified dust-laden exhaust gas, the second-stage dust-laden exhaust gas, and the third-stage dust-laden exhaust gas are transported to the third dust collector for dust collection, obtaining the black powder and exhaust gas from the air-classified dust-laden exhaust gas, the second-stage dust-laden exhaust gas, and the third-stage dust-laden exhaust gas. This allows the coarsely crushed dust-laden exhaust gas, the first-stage dust-laden exhaust gas, the air-classified dust-laden exhaust gas, the second-stage dust-laden exhaust gas, and the third-stage dust-laden exhaust gas to be collected nearby, shortening the exhaust gas transport distance and reducing the size of the dust collection device.

[0101] In an optional embodiment, the waste gas generated in each process step of this embodiment is transported to a tail gas treatment device for tail gas treatment before being discharged. The tail gas treatment includes steps such as thermal combustion, multi-stage alkaline spraying, and activated carbon system.

[0102] Based on the above-described process for crushing and sorting retired lithium-ion batteries, a specific embodiment of this process is summarized below:

[0103] Figure 4The flowchart of the decommissioned lithium-ion battery crushing and sorting process provided in the embodiments of the present invention is shown below. Figure 4 As shown, the crushing and sorting process for retired lithium-ion batteries includes:

[0104] 1. Retired lithium-ion batteries smaller than 500mm do not require discharge and are directly fed to the crusher. The crusher's blades shred the individual batteries, completing the coarse crushing process. The particle size of the coarsely crushed material is less than 40mm. During this process, nitrogen gas is continuously introduced as a protective gas, and an external fan is used to promptly draw the volatile electrolyte to the first dust collector (bag filter). After dust removal, the exhaust gas is sent to the tail gas treatment device for combustion, followed by multi-stage alkaline spraying and activated carbon adsorption to thoroughly remove sulfur dioxide (F) and phosphorus (P). The qualified exhaust gas is directly discharged into the atmosphere, ensuring the safe crushing of individual batteries and preventing fires. The crusher's crushing chamber can be equipped with an oxygen detector and an organic gas detector to control the oxygen content and organic gas content to below 5% and 120mg / m3, respectively.

[0105] 2. The material after coarse crushing is conveyed to a rotary kiln for low-temperature drying. The temperature of low-temperature drying is 100℃-200℃, which allows the electrolyte remaining after coarse crushing to volatilize in the form of fluoride and organic gases.

[0106] 3. The material, after being dried at low temperature, is further reduced in particle size by shearing to meet the particle size requirements of the subsequent air classification equipment. Then, a 4mm single-layer vibrating screen is used to separate the material into two categories: materials larger than 4mm (approximately 40%) and materials smaller than 4mm (approximately 50%). The remaining diaphragm and dust (approximately 10%) and the dust generated from shearing and crushing are carried by the airflow into bag filter I. The materials smaller than 4mm do not contain the outer shell or diaphragm and can directly enter the pulverizing stage.

[0107] 4. The diaphragm and dust in bag filter I are screened by a drum screen. The dust that is screened off is recovered as black powder, and the material that is screened on is the qualified diaphragm product. The exhaust gas in bag filter I enters the thermal combustion system for treatment, and then undergoes multi-stage alkaline spraying and activated carbon adsorption to completely remove F and P. The qualified exhaust gas is directly discharged into the atmosphere.

[0108] 5. After screening by the vibrating screen, materials larger than 4mm enter the outer shell of the folding plate air classifier, and the remaining electrode material enters the flexible crushing stage.

[0109] 6. The remaining electrode material is conveyed to the flexible crushing device, which includes a drum screen and a rod mill system located inside the drum screen and rotating coaxially with the drum screen. After the remaining electrode material is ground by the rod mill and impact grinding of the flexible crushing device, selective crushing is achieved, that is, the electrode is crushed into smaller particles (less than 4mm) while the outer shell retains its complete shape. After being screened by the drum screen, the electrode material under the screen enters the pulverization and powdering stage, and the outer shell on the screen is combined with the air-classified outer shell as the final outer shell product.

[0110] 7. The materials smaller than 4mm from the vibrating screen and the materials smaller than 4mm from the drum screen are combined and used as raw materials for crushing electrode sheets. They are then conveyed to the crushing and pulverizing equipment. The crusher blades strike the electrode sheet material, causing the copper and aluminum electrode sheets to separate from the black powder attached to them. The separated material is then screened in two stages to recover the black powder product and the copper and aluminum particle mixture, respectively.

[0111] 8. The copper-aluminum particle mixture is fed into a gravity separator, where copper and aluminum products are obtained separately under its own gravity and screening action.

[0112] 9. Dust generated from the folding plate air separation, flexible crushing, pulverizing, two-stage screening and gravity separation processes flows into the third dust collector (bag dust collector II). The dust is part of the black powder product. The exhaust gas enters the thermal combustion treatment, and then undergoes multi-stage alkaline spraying and activated carbon adsorption to completely remove F and P. The qualified exhaust gas is directly discharged into the atmosphere.

[0113] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A process for crushing and sorting retired lithium-ion batteries, characterized in that, include: The retired lithium-ion batteries that have not undergone discharge treatment are subjected to primary crushing to obtain coarse crushed material and coarse crushed dust-containing exhaust gas. The primary crushing is an on-line crushing process, comprising: conveying the retired lithium-ion batteries that have not undergone discharge treatment to a primary crusher, and shredding the retired lithium-ion batteries in the primary crusher under preset conditions to obtain coarse crushed material; the particle size of the coarse crushed material is less than 40 mm; the preset conditions include: the oxygen content inside the crusher is less than a preset oxygen content, and the organic gas content inside the crusher is less than a preset organic gas content. The coarsely crushed material is dried at a set temperature to obtain dried material and drying exhaust gas; The dried material undergoes secondary crushing, and the crushed material is then subjected to primary screening to obtain primary undersize material, primary oversize material, and primary dust-laden exhaust gas. The secondary crushing includes: conveying the dried material to a secondary crusher for shearing and fine crushing to obtain finely crushed material with a particle size less than 20 mm; and conveying the finely crushed material to a second screening device for primary screening to obtain the primary undersize material, primary oversize material, and primary dust-laden exhaust gas. The primary undersize material has a particle size less than 4 mm, and the primary oversize material has a particle size greater than or equal to 4 mm. The material over the primary sieve is subjected to air separation to obtain the casing of the retired lithium-ion battery, primary electrode material, and dust-laden exhaust gas from air separation. The primary electrode material is crushed three times to obtain the casing of the retired lithium-ion battery, the secondary electrode material, and the secondary dust-laden exhaust gas. This process includes: conveying the primary electrode material to a flexible crushing device, whereby the flexible crushing device flexibly crushes the primary electrode material to obtain the casing of the retired lithium-ion battery, the secondary electrode material, and the secondary dust-laden exhaust gas; the flexible crushing device includes a rod mill system and a drum screen, with the rod mill system disposed within the drum of the drum screen; the particle size of the secondary electrode material is less than or equal to 4 mm. The primary undersize material and the secondary electrode material are pulverized and powdered, and the pulverized material is then subjected to secondary sieving to obtain a copper-aluminum electrode mixture, black powder, and tertiary dust-containing waste gas.

2. The decommissioned lithium-ion battery crushing and sorting process according to claim 1, characterized in that, Also includes: The coarse crushed dust-laden exhaust gas, the primary dust-laden exhaust gas, the air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas are transported to a dust collection device for dust-gas separation.

3. The decommissioned lithium-ion battery crushing and sorting process according to claim 2, characterized in that, The dust collection device includes a first dust collector, a second dust collector, and a third dust collector; The coarse crushed dust-laden exhaust gas, the primary dust-laden exhaust gas, the air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas are transported to a dust collection device for dust-gas separation, including: The coarse crushing dust-laden exhaust gas is transported to the first dust collector, and dust is collected by the first dust collector to separate the black powder and exhaust gas in the coarse crushing dust-laden exhaust gas; The primary dust-laden exhaust gas is transported to the second dust collector, where dust is collected to obtain primary dust and exhaust gas. The air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas are transported to a third dust collector, where dust is collected to obtain the black powder and exhaust gas in the air-separated dust-laden exhaust gas, the secondary dust-laden exhaust gas, and the tertiary dust-laden exhaust gas.

4. The decommissioned lithium-ion battery crushing and sorting process according to claim 3, characterized in that, Also includes: The primary dust is conveyed to the first screening device so that the first screening device can screen the primary dust to obtain a diaphragm and black powder.

5. The decommissioned lithium-ion battery crushing and sorting process according to claim 1, characterized in that, Also includes: The copper-aluminum electrode mixture is subjected to gravity separation to obtain copper particles, aluminum particles, and separated dust-containing waste gas.

6. The decommissioned lithium-ion battery crushing and sorting process according to claim 1, characterized in that, The coarsely crushed material is dried at a set temperature to obtain dried material, comprising: The coarsely crushed material is conveyed to a rotary kiln, so that the rotary kiln dries the coarsely crushed material at a set temperature; the set temperature ranges from 100℃ to 200℃.

7. The decommissioned lithium-ion battery crushing and sorting process according to claim 3, characterized in that, Also includes: The waste gas is transported to an exhaust gas treatment device for treatment.

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