Pyrolysis system for waste lithium battery material

Abstract

The utility model discloses a pyrolysis system for waste lithium battery materials, which comprises a pyrolysis reactor and a pyrolysis rotary kiln, and the material output end of the pyrolysis reactor is connected with the feed port of the pyrolysis rotary kiln; the air inlet of the pyrolysis reactor is communicated with an air source, and the air inlet of the pyrolysis rotary kiln is communicated with a nitrogen source. Through the grading synergistic effect of the pyrolysis reaction device and the pyrolysis rotary kiln, the pyrolysis degree is obviously improved, pyrolysis is more sufficient, the impurity content of pyrolysis products is greatly reduced, the raw material quality of the follow-up recovery process is improved, and the metal recovery rate and the product quality in the whole recovery process can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to waste lithium battery recycling processing technical field especially relates to a kind of pyrolysis systems of waste lithium battery material. BACKGROUND

[0002] Waste lithium battery contains more heavy metals, if direct landfill, the heavy metals in it will gradually seep out, slowly pollute soil and groundwater, cause irreversible damage to ecological environment. Moreover, waste lithium battery contains rich lithium, copper, cobalt and other metal resources, and the content is much higher than the corresponding metal content in natural ore, with very high recycling value. At present, the recycling of waste lithium battery mainly adopts fire metallurgy and wet metallurgy two methods, and pretreatment is an indispensable link of fire metallurgy and wet metallurgy, which can obtain black powder enriched in positive and negative materials, mainly including discharging, disassembly, crushing, heat treatment, sorting and other processes, and heat treatment is the key step to realize the effective separation of electrode material and electrolyte, diaphragm, binder and current collector, which has a crucial influence on the smooth progress of subsequent recovery process and the quality of recovery products.

[0003] The heat treatment method in the prior art is commonly used high-temperature vacuum pyrolysis method, and the single pyrolysis method is usually adopted in the prior art. The pyrolysis device in the prior art is used to perform high-temperature pyrolysis on waste lithium battery in a nitrogen atmosphere. In this process, the nitrogen atmosphere is relatively stable, but the pyrolysis process is not sufficient. Insufficient pyrolysis cannot completely separate the electrode material from other components, thereby affecting the quality of black powder in the subsequent process, reducing the efficiency and economic benefit of the entire recovery process, and the energy utilization rate of the pyrolysis device in the prior art is low. UTILITY MODEL CONTENT

[0004] In view of the deficiencies in the prior art, the utility model provides a pyrolysis system for waste lithium battery material, which solves the problems of insufficient pyrolysis and low energy utilization rate in the prior art by setting the pyrolysis reactor and the pyrolysis rotary kiln.

[0005] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0006] In the first aspect, the utility model provides a pyrolysis system for waste lithium battery material, which comprises a pyrolysis reactor and a pyrolysis rotary kiln, wherein the material output end of the pyrolysis reactor is connected with the feed inlet of the pyrolysis rotary kiln.

[0007] The air source is communicated with the gas inlet of the pyrolysis reactor, and the nitrogen source is communicated with the gas inlet of the pyrolysis rotary kiln.

[0008] As a further technical scheme, the pyrolysis reactor is provided with a double-shaft stirring structure in the inside, and the double-shaft stirring structure comprises two mutually parallel stirring shafts.

[0009] As a further technical scheme, a plurality of stirring parts are arranged on each stirring shaft.

[0010] As a further technical scheme, the stirring part comprises a strip structure and a scraper; strip hooks are integrally arranged on both sides of the strip structure.

[0011] As a further technical scheme, the stirring parts on the two stirring shafts are staggered.

[0012] As a further technical scheme, the pyrolysis rotary kiln comprises a roller, and a plurality of scooping plate structures are arranged on the inner wall of the roller.

[0013] As a further technical scheme, a spiral conveying structure is arranged on the rotating shaft of the roller.

[0014] As a further technical scheme, the air source is communicated with the pyrolysis reactor, and is used for introducing control air into the pyrolysis reactor, so as to ensure that the pyrolysis reactor is in an air atmosphere.

[0015] As a further technical scheme, the pyrolysis system further comprises a steam source, and the steam source is respectively communicated with the pyrolysis reactor and the pyrolysis rotary kiln.

[0016] As a further technical scheme, the nitrogen source is connected with the pyrolysis rotary kiln, and a steam heater is arranged between the nitrogen source and the pyrolysis rotary kiln, and the steam heater is used for heating the nitrogen source.

[0017] The one or more technical schemes of the utility model have the following beneficial effects:

[0018] 1. The pyrolysis system is two-stage pyrolysis, mainly comprising a pyrolysis reactor and a pyrolysis rotary kiln, compared with a traditional single pyrolysis mode, through the grading and synergistic effect of the pyrolysis reaction device and the pyrolysis rotary kiln, the pyrolysis degree is obviously improved, the pyrolysis is more sufficient, the impurity content of the pyrolysis product is greatly reduced, the raw material quality of the subsequent recovery process is improved, and the metal recovery rate and product quality of the whole recovery process are improved.

[0019] 2. The double-shaft stirring structure is arranged in the pyrolysis reactor, and the material scooping plate and the spiral conveying structure are arranged in the pyrolysis rotary kiln, so that a certain shearing force is provided for the material, the pyrolysis contact area of the material is increased, the lumps in the material are destroyed, the uniformity of pyrolysis is ensured, and the pyrolysis is more sufficient.

[0020] 3. The pyrolysis reactor is connected with the air source, so that the inside of the pyrolysis reactor adopts an air atmosphere, compared with the traditional inert atmosphere, the pyrolysis is more complete and more sufficient.

[0021] 4. The pyrolysis reactor of this invention has an air atmosphere inside, while the pyrolysis rotary kiln has a nitrogen atmosphere inside. Compared with the traditional vacuum pyrolysis system, the amount of nitrogen used is greatly reduced. In addition, the temperature ranges set in the pyrolysis reactor and the pyrolysis rotary kiln are different, which greatly improves the energy utilization rate while ensuring full pyrolysis. Attached Figure Description

[0022] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0023] Figure 1 This is a schematic diagram of the pyrolysis system for waste lithium battery materials according to this utility model;

[0024] Figure 2 This is a schematic diagram of the dual-shaft stirring structure inside the pyrolysis reactor of this utility model;

[0025] The components include: 1. Pyrolysis reactor; 1-1. Twin-shaft stirring structure; 1-1-1. Material conveying structure; 1-1-2. Scraper; 1-1-3. Material hook; 2. Pyrolysis rotary kiln; 2-1. Material lifting plate; 2-2. Screw conveyor structure; 3. Steam heater; 4. Air source; 5. Steam source; 6. Nitrogen source; 7. Discharge port; 8. Material input end. Detailed Implementation

[0026] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] Example 1

[0028] This utility model provides a pyrolysis treatment system for waste lithium battery materials, such as... Figure 1 As shown, the pyrolysis treatment system includes a pyrolysis reactor 1, a pyrolysis rotary kiln 2, an air source 4, a steam source 5, and a nitrogen source 6. The material output end of the pyrolysis reactor 1 is connected to the feed inlet of the pyrolysis rotary kiln 2. Both the gas outlet of the pyrolysis reactor and the gas outlet of the pyrolysis rotary kiln are connected to fans, and the exhaust gas is discharged through the fans. The discharged exhaust gas can also be further treated, and the specific treatment process can be set according to actual needs. In this embodiment, the temperature inside the pyrolysis rotary kiln is higher than the temperature inside the pyrolysis reactor. Specifically, the temperature inside the pyrolysis reactor is set to 200℃-300℃, while the temperature inside the pyrolysis rotary kiln is set to 550℃-600℃.

[0029] In this embodiment, as Figure 1 As shown, air source 4 is connected to pyrolysis reactor 1, so that the atmosphere inside the pyrolysis reactor is air, ensuring that air is used as the reaction medium in the pyrolysis reaction device. On the one hand, compared with the traditional inert atmosphere, the pyrolysis in this embodiment is more complete and more thorough. On the other hand, it reduces the dependence on inert gases (such as nitrogen), thereby reducing the amount of nitrogen used.

[0030] Steam source 5 is connected to pyrolysis reactor 1 and pyrolysis rotary kiln 2 respectively. Specifically, steam is introduced into the rotating shaft of pyrolysis reactor and the inner wall of pyrolysis reaction device to exchange heat with materials in an indirect heating manner; on the other hand, steam is introduced into the inner wall of pyrolysis rotary kiln to provide heat to materials.

[0031] The nitrogen source is connected to the pyrolysis rotary kiln, specifically: such as Figure 1 As shown, a steam heater 3 is installed between the nitrogen source 6 and the pyrolysis rotary kiln. One end of the steam heater is connected to the nitrogen source, and the other end of the steam heater is connected to the pyrolysis rotary kiln. The steam heater is used to heat the nitrogen source.

[0032] In this embodiment, the pyrolysis reactor 1 is equipped with a biaxial stirring structure 1-1, such as... Figure 2 As shown, the dual-shaft stirring structure includes two stirring shafts, each equipped with several stirring units. The stirring components on the two shafts are arranged in an alternating pattern. Each stirring component includes a material carrier structure 1-1-1 and a scraper 1-1-2. The material carrier structure 1 scoops up the material, increasing the contact area between the material and the dual-shaft stirring structure. The scraper 2 removes material from the inner wall of the pyrolysis reactor and the stirring shafts. The rotation of the stirring shafts moves the material forward and provides a certain shear force, breaking up clumps in the material and ensuring complete pyrolysis in the subsequent rotary kiln. In this embodiment, material carrier hooks 1-1-3 are integrated on both sides of the material carrier structure for scooping up the material. The dual-shaft stirring structure in the pyrolysis reactor provides a certain shear force to the material, increasing the pyrolysis contact area, breaking up clumps, ensuring the uniformity of pyrolysis, and further enhancing the completeness of pyrolysis.

[0033] In this embodiment, as Figure 1 As shown, the pyrolysis rotary kiln includes a drum. Several lifting plate structures are installed on the inner wall of the drum, and a spiral conveying structure is installed on the rotating shaft of the drum. Specifically, as the drum rotates, the lifting plate structures on the inner wall of the drum can lift the material. The spiral conveying structure inside the drum drives the material to move. While conveying the material, it also provides a certain shearing force to the material that falls after being lifted by the lifting plate structures, breaking up the clumps in the material and ensuring the uniformity of pyrolysis.

[0034] This embodiment provides a pyrolysis system for waste lithium battery materials. The specific working process is as follows: it includes two parts: a pyrolysis process and a high-temperature pyrolysis process. In the pyrolysis process, upstream materials (waste lithium batteries after discharge, dismantling, and crushing) enter the interior of the pyrolysis reactor through the material input end. The internal temperature of the pyrolysis reactor is set to 200℃-300℃. The electrolyte in the waste lithium battery materials (mainly carbonate compounds) volatilizes and decomposes into gaseous alkane compounds at this temperature. Because the interior of the pyrolysis reactor is an air atmosphere, the gaseous alkane compounds can fully contact oxygen and undergo an oxidation reaction, ultimately producing carbon dioxide and water. Compared with traditional vacuum pyrolysis methods, this reaction path avoids the problem of alkane compounds generating pyrolysis oil under vacuum and high-temperature conditions. The reduction of pyrolysis oil not only reduces the content of organic pollutants in the exhaust gas, making the exhaust gas composition relatively simple, but also greatly reduces the difficulty of exhaust gas treatment.

[0035] The twin-shaft stirring structure in the pyrolysis reactor drives the material movement. The material-carrying structure on the twin-shaft stirring structure can lift the material, increasing the contact area between the material and the stirring unit. The scraper on the twin-shaft stirring structure can remove the material on the inner wall of the pyrolysis reactor. The rotation of the stirring shaft of the twin-shaft stirring structure drives the material movement and provides shear force to break up the clumps in the material. The material decomposes inside the pyrolysis reactor, and the generated exhaust gas is discharged from the gas outlet of the pyrolysis reactor along with air. The exhaust gas can also be further treated, and the specific treatment process can be set according to actual needs.

[0036] The high-temperature pyrolysis process is as follows: After being processed by the pyrolysis reactor, the waste lithium batteries enter the drum inside the pyrolysis rotary kiln through the feed inlet of the pyrolysis rotary kiln from the material output end of the pyrolysis reactor. The internal temperature of the pyrolysis rotary kiln is set at 550℃-600℃, and the interior of the pyrolysis rotary kiln is in a nitrogen atmosphere. A screw conveyor structure drives the material to move in the drum, where the material undergoes high-temperature pyrolysis. The high-temperature pyrolysis process removes the binder in the material at 550℃-600℃. The main component of the binder is polyvinylidene fluoride, which produces fluorine-containing compounds after high-temperature pyrolysis. These fluorine-containing compounds are discharged through the gas outlet of the pyrolysis rotary kiln along with nitrogen gas. The discharged tail gas can also be further treated, and the specific treatment process can be set according to actual needs.

[0037] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A pyrolysis system for waste lithium battery materials, characterized in that, include: A pyrolysis reactor and a pyrolysis rotary kiln, wherein the material output end of the pyrolysis reactor is connected to the feed inlet of the pyrolysis rotary kiln; An air source is connected to the air inlet of the pyrolysis reactor, and a nitrogen source is connected to the air inlet of the pyrolysis rotary kiln.

2. The pyrolysis system for waste lithium battery materials as described in claim 1, characterized in that, The pyrolysis reactor is equipped with a biaxial stirring structure, which includes two parallel stirring shafts.

3. The pyrolysis system for waste lithium battery materials as described in claim 2, characterized in that, Each of the aforementioned stirring shafts is equipped with several stirring components.

4. The pyrolysis system for waste lithium battery materials as described in claim 3, characterized in that, The mixing component includes a material conveying structure and a scraper; the material conveying structure has integrated material conveying hooks on both sides.

5. The pyrolysis system for waste lithium battery materials as described in claim 3, characterized in that, The stirring components on the two stirring shafts are arranged alternately.

6. The pyrolysis system for waste lithium battery materials as described in claim 1, characterized in that, The pyrolysis rotary kiln includes a drum, and the inner wall of the drum is provided with a number of lifting plate structures.

7. The pyrolysis system for waste lithium battery materials as described in claim 6, characterized in that, A screw conveyor structure is installed on the rotating shaft of the drum.

8. The pyrolysis system for waste lithium battery materials as described in claim 1, characterized in that, The air source is connected to the pyrolysis reactor and is used to control the flow of air into the pyrolysis reactor to ensure that the interior of the pyrolysis reactor is filled with air.

9. The pyrolysis system for waste lithium battery materials as described in claim 1, characterized in that, The pyrolysis system also includes a steam source, which is connected to both the pyrolysis reactor and the pyrolysis rotary kiln.

10. The pyrolysis system for waste lithium battery materials as described in claim 1, characterized in that, The nitrogen source is connected to the pyrolysis rotary kiln, and a steam heater is provided between the nitrogen source and the pyrolysis rotary kiln for heating the nitrogen source.

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