Crushing, sorting and high-value utilization method for car shells of scrapped electric cars

Abstract

The invention discloses a scrap electric vehicle shell crushing, sorting and high-value utilization method. The method comprises the following steps: (1) collecting crushed materials obtained after the scrapped electric vehicle is crushed; (2) dividing the crushed materials into large materials, medium materials and small materials according to particle sizes; (3) the obtained small materials are subjected to sinking and floating differences in the dense medium suspension liquid, and effective separation of glass and non-metal impurities is achieved; (4) carrying out electrostatic separation on the intermediate material to separate out a mixture containing the rubber and the fiber reinforced resin composite material, carrying out first-stage pyrolysis on the mixture to obtain fibers, fuel oil and fuel gas products, carrying out second-stage reforming on the fuel oil and fuel gas products to obtain synthesis gas, and carrying out oxidation carbon removal on the fibers for regenerated composite material manufacturing; and (5) after the large materials are crushed, iron and a mixture of copper and aluminum are obtained through magnetic separation and eddy current separation in sequence, and regenerated metal is obtained. The method provided by the invention not only can improve the current resource recovery rate, but also has the advantages of high sorting precision, directional regeneration and low environmental influence.

Description

Technical fields:

[0001] This invention relates to the field of end-of-life electric vehicle recycling and resource recycling technology, specifically to a method for crushing, sorting, and high-value utilization of end-of-life electric vehicle shells. Background technology:

[0002] With the rapid increase in the number of electric vehicles worldwide, the amount of scrapped electric vehicles is also rising. The discarded vehicle shells are complex in composition, mainly including steel, aluminum, plastic, resin, rubber, wires, and other materials. Traditional dismantling methods rely on simple crushing and sorting techniques, which are difficult to efficiently and accurately separate various materials. At the same time, the different components of the vehicle debris residue cannot be effectively recycled and reused, resulting in a large waste of resources.

[0003] Current technologies primarily employ mechanical crushing to initially dismantle vehicle shell materials, supplemented by simple magnetic separation and sieving to separate metals and non-metals. However, their effectiveness is limited, especially since there is no systematic recycling method capable of efficiently separating and recycling the various components in the vehicle shell fragments. Therefore, there is an urgent need to develop a highly efficient sorting and high-value utilization process for recycling crushed vehicle shells. Summary of the Invention:

[0004] This invention solves the problems existing in the prior art and provides a method for crushing, sorting and high-value utilization of scrapped electric vehicle shells. Through steps such as graded screening, magnetic separation, eddy current separation, and heavy medium separation, recyclable materials of different materials are effectively separated. At the same time, according to the characteristics of the sorted materials, different components of waste are recycled and reused by implementing measures according to the materials, so as to achieve efficient sorting and high-value utilization of scrapped electric vehicle shell crushed products.

[0005] The purpose of this invention is to provide a method for crushing, sorting, and high-value utilization of scrapped electric vehicle shells, comprising the following steps:

[0006] (1) Crushing: Collecting the crushed material from dismantled, compressed and crushed scrapped electric vehicles;

[0007] (2) Grading and screening: The crushed material is divided into large, medium and small particles according to particle size by a multi-stage air separation screening device;

[0008] (3) Small material sorting: The obtained small material mixture is sorted by heavy medium, which utilizes the difference in the sinking and floating of substances with different densities in heavy medium suspension to achieve effective separation of glass and non-metallic impurities;

[0009] (4) Middle material sorting: The middle material mixture obtained by grading and screening is separated by electrostatic separation to separate the mixture containing rubber and fiber reinforced resin composite. The mixture is pyrolyzed in one stage to obtain fiber, fuel oil and gas products. The fuel oil and gas products are reformed in two stages to obtain syngas. The fiber is oxidized and decarbonized before being used for the manufacture of recycled composite.

[0010] (5) Large material sorting: After the large material mixture obtained by grading and screening is further crushed, it is then separated by magnetic separation and eddy current separation in sequence to obtain a mixture of iron, copper and aluminum, thereby obtaining recycled metal.

[0011] Preferably, the crushed material in step (1) is specifically the crushed material after hammer mill crushing, which includes metal, fiber-reinforced resin composite, rubber, and glass. In step (1), the scrapped electric vehicle shell is fed into a crushing device for preliminary crushing to obtain coarse material with larger particle sizes. This stage uses a hammer mill crushing device to break down the shell into larger fragments while retaining the main structural materials.

[0012] Preferably, in step (2), the particle size of the large material is greater than 50 mm, the particle size of the medium material is 10-50 mm, and the particle size of the small material is less than 10 mm.

[0013] Preferably, the bulk materials mentioned in step (2) include car body structural steel and large metal parts, the medium materials include fiber-reinforced resin composites and rubber, and the small materials include non-metallic impurities and glass. The bulk materials also include large pieces of sponge.

[0014] The multi-stage air separation and screening equipment proposed in this invention utilizes the dual effects of air force and screening, combined with the density and particle size differences of the material, to separate the crushed product into three different particle sizes: large, small, and medium, for subsequent sorting and processing.

[0015] The heavy medium suspension mentioned in step (3) is obtained by adding a high-density medium to water to form a heavy medium suspension, thereby utilizing the difference in sedimentation velocity of materials with different densities in the heavy medium suspension to achieve glass separation.

[0016] In step (3), the mixture of small materials obtained by grading and screening is separated by heavy medium separation. That is, by utilizing the difference in the sinking and floating of substances with different densities in heavy medium suspension, glass and non-metallic impurities can be effectively separated. The glass powder can be made into recycled glass after being classified, cleaned, melted and shaped.

[0017] Further preferably, the high-density medium is magnetite powder, and the amount of high-density medium added is 1.3-1.8 kg per liter of water.

[0018] Preferably, the conditions for electrostatic separation in step (4) are: the electrostatic field strength is 30-80 kV / cm, and it needs to be carried out in an environment with a relative humidity of 20%-30%. In actual electrostatic separation, the electrostatic field strength and relative humidity can be finely adjusted according to the actual separation effect to obtain the best separation effect. Electrostatic separation uses a high-voltage electrostatic field to separate substances with different charge characteristics (i.e., using the difference in the charged properties of different materials in an electric field). After the materials are charged in the electrostatic field, materials with large differences in charged properties are separated under the action of electrostatic force, achieving fine separation.

[0019] The mixture is pyrolyzed in one stage to obtain fiber, fuel oil and gas products. The fuel oil and gas products are reformed in two stages to obtain syngas. The fiber is oxidized and decarbonized before being used to manufacture recycled composite materials to obtain recycled fiber.

[0020] Preferably, the first-stage pyrolysis conditions in step (4) are: pyrolysis temperature 400℃-600℃, retention time 10-30min; the second-stage reforming conditions are: reforming temperature 700℃-900℃, retention time 5-15min.

[0021] Preferably, the magnetic separation conditions in step (5) are: a magnetic field strength of 2000-5000 Gauss. For mixtures containing a large amount of fine iron filings, high-intensity magnetic separation equipment (such as a permanent magnet separator or an electromagnetic separator) can be used for separation to improve separation efficiency and purity. Magnetic separation utilizes the attraction of a magnetic field on magnetic materials to separate ferrous metals from the mixture. By adjusting the magnetic field strength, different magnetic material contents and particle sizes can be accommodated.

[0022] Preferably, the conditions for eddy current separation in step (5) are: magnetic field strength of 3000-6000 Gauss and rotation speed of 1000-3000 rpm. Eddy current separation utilizes the high-speed rotating magnetic field to induce eddy currents in conductive materials (such as light metals like aluminum and copper), and the resulting reverse magnetic field pushes these materials away from the mixture, thus achieving separation.

[0023] Compared with existing technologies, this invention has the following advantages: The method proposed in this invention effectively separates recyclable materials of different types through steps such as grading and screening, magnetic separation, eddy current separation, and heavy medium separation. Simultaneously, based on the characteristics of the separated materials, it implements tailored strategies for the recycling and reuse of different waste components, achieving efficient sorting and high-value utilization of resources from the crushed shells of scrapped electric vehicles. The method proposed in this invention not only improves the current resource recovery rate but also has the advantages of high sorting accuracy, directional regeneration, and low environmental impact. Attached image description:

[0024] Figure 1 This is a process flow diagram of a method for crushing, sorting, and high-value utilization of scrapped electric vehicle shells according to the present invention. Detailed implementation method:

[0025] The following embodiments are further illustrations of the present invention, but not limitations thereof.

[0026] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention. Unless otherwise specified, the experimental materials and reagents used herein are commercially available products conventionally available in this technical field.

[0027] Example 1:

[0028] like Figure 1 As shown, a method for crushing, sorting, and high-value utilization of scrapped electric vehicle shells includes the following steps:

[0029] (1) Crushing: Collecting crushed materials from electric vehicles after dismantling, compression, and hammer grinding. The crushed materials include metal, plastic and composite materials, rubber and glass fragments or powder.

[0030] (2) Grading and Screening: A multi-stage air-separation screening device is used to screen the crushed products based on their density and particle size differences. The multi-stage air-separation screening device utilizes the excitation force generated by the vibrating motor and the airflow generated by the circulating fan to classify the crushed products according to their particle size. In this embodiment, the grading and screening process is used to separate the crushed material into three different particle sizes (50mm, 10mm): large, small, and medium, for subsequent sorting and processing.

[0031] (3) Large material sorting: For the large material section, magnetic separation (magnetic field strength 4000 Gauss) is used to separate the iron components. Then, eddy current separation (magnetic field strength 5000 Gauss, rotation speed 2000 rpm) is used to separate the copper and aluminum components. The separated iron, copper and aluminum are further purified to obtain recycled metal.

[0032] (4) Small-item sorting: For the small-item portion, a heavy media sorting process is used to separate the glass components. The heavy media sorting process involves adding magnetite powder to water to form a heavy media suspension (1.5 kg of magnetite powder is added per liter of water). Materials of different densities settle at different rates in the suspension, thus separating the glass from non-metallic impurities. Due to its higher density, the glass settles quickly and is separated. This glass component is then processed through a melt-forming process to ultimately obtain recycled glass.

[0033] (5) Middle-grade material sorting: For the middle-grade material, an electrostatic sorting process (electrostatic field strength 50kV / cm, and must be carried out in an environment with 20%-30% relative humidity) is used to further separate the organic components containing rubber, fiber-reinforced composite materials, and polymers. This organic component is collected and first undergoes a pyrolysis process (pyrolysis temperature 500℃, retention time 20min) under anaerobic conditions to generate fuel oil, fuel gas, fibers, and other products. Subsequently, the fuel oil and other organic products enter a second-stage reforming process (reforming temperature 800℃, retention time 10min) for high-temperature reforming to improve the quality, ultimately yielding syngas. The fibers separated from the first-stage pyrolysis are oxidized and decarbonized before being separated and recovered; the fibers can be further used in the manufacture of composite materials.

[0034] Example 2

[0035] Similar to Example 1, except that: in step (3), the magnetic field strength in the magnetic separation process is 2000 Gauss, the magnetic field strength in the eddy current separation process is 6000 Gauss, and the rotation speed is 1000 rpm. In step (4), the amount of magnetite powder added is 1.3 kg of magnetite powder per liter of water. In step (5), the electrostatic field strength is 30 kV / cm, the pyrolysis temperature of the first stage is 400℃, the retention time is 30 min, and the reforming temperature of the second stage is 700℃, and the retention time is 15 min.

[0036] Example 3

[0037] Similar to Example 1, except that: in step (3), the magnetic field strength in the magnetic separation process is 5000 Gauss, the magnetic field strength in the eddy current separation process is 3000 Gauss, and the rotation speed is 3000 rpm. In step (4), the amount of magnetite powder added is 1.8 kg of magnetite powder per liter of water. In step (5), the electrostatic field strength is 80 kV / cm, the pyrolysis temperature of the first stage is 600℃, the retention time is 10 min, and the reforming temperature of the second stage is 900℃, the retention time is 5 min.

[0038] The above description of the embodiments is only for the purpose of helping to understand the technical solution and core idea of ​​the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for shredding and sorting of end-of-life electric vehicle body shells and high value utilization, characterized in that, The method comprises the following steps: (1) crushing: collecting the crushed material after the scrapped electric vehicle is disassembled, compressed and crushed; (2) grading and screening: grading and screening the crushed material by a multi-stage air separation screening device according to particle size to obtain large material, medium material and small material; (3) small material separation: separating the obtained small material mixture by heavy medium separation, utilizing the difference in sinking and floating of different density materials in the heavy medium suspension to realize effective separation of glass and non-metallic impurities; (4) medium material separation: separating the medium material mixture obtained by grading and screening by electrostatic separation to separate the mixture containing rubber and fiber reinforced resin composites, obtaining fiber, fuel oil and gas products from the mixture by one-stage pyrolysis, obtaining synthesis gas from the fuel oil and gas products by two-stage reforming, and using the fiber after carbon removal by oxidation for the manufacture of regenerated composites; (5) large material separation: further crushing the large material mixture obtained by grading and screening, and then sequentially separating by magnetic separation and eddy current separation to sequentially obtain iron and a mixture of copper and aluminum, thereby obtaining regenerated metal.

2. The method of claim 1, wherein, The crushed material in step (1) is specifically hammer crushed material, and the crushed material comprises metal, fiber reinforced resin composites, rubber and glass.

3. The method of claim 1, wherein, In step (2), the particle size of the large material is greater than 50 mm, the particle size of the medium material is 10-50 mm, and the particle size of the small material is less than 10 mm.

4. The method of claim 1, wherein, In step (2), the large material comprises vehicle shell structural steel and large metal parts, the medium material comprises fiber reinforced resin composites and rubber, and the small material comprises non-metallic impurities and glass.

5. The method of claim 1, wherein, In step (3), the heavy medium suspension is formed by adding high-density medium to water, thereby utilizing the difference in sinking speed of materials with different densities in the heavy medium suspension to realize separation of glass.

6. The method of claim 5, wherein, The high-density medium is magnetite powder, and the addition amount of the high-density medium is 1.3-1.8 kg per liter of water.

7. The method of claim 1, wherein, In step (4), the electrostatic separation is performed in a 20%-30% relative humidity environment with an electrostatic field strength of 30-80 kV / cm.

8. The method according to claim 1 or 7, characterized in that, In step (4), the one-stage pyrolysis is performed at a pyrolysis temperature of 400-600°C for 10-30 min, and the two-stage reforming is performed at a reforming temperature of 700-900°C for 5-15 min.

9. The method of claim 1, wherein, In step (5), the magnetic separation is performed at a magnetic field strength of 2000-5000 Gauss.

10. The method according to claim 1 or 9, characterized in that, In step (5), the eddy current separation is performed at a magnetic field strength of 3000-6000 Gauss and a rotation speed of 1000-3000 revolutions per minute.

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