Recycling process of lithium battery aluminum slag
By employing magnetic separation, mixing, multi-stage separation, and vacuum melting processes for lithium battery aluminum slag, the fire risks associated with grinding, storing, and transporting aluminum slag have been eliminated, achieving efficient and safe aluminum slag treatment and aluminum ingot production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG YIYUAN NEW ENERGY MATERIALS TECHNOLOGY CO LTD
- Filing Date
- 2026-03-12
- Publication Date
- 2026-05-19
AI Technical Summary
There is a risk of fire during the grinding, storage and transportation of aluminum slag for lithium batteries, especially due to the static accumulation of aluminum powder and the sparks and explosion hazards caused by friction. Traditional processes have not been able to effectively solve this problem.
After being demagnetized by a magnetic separator, it is mixed with fatty acids and activated carbon, and then separated in multiple stages by a grinder and grading equipment. After being pressed into briquettes, it is vacuum melted. The synergistic effect of fatty acids and activated carbon is used to reduce the risk of static electricity, and the negative pressure environment reduces dust.
It effectively reduces the fire risk of aluminum slag during grinding, storage and transportation, improves the activity and quality of aluminum powder, ensures transportation safety, and improves the yield and quality of aluminum ingots.
Smart Images
Figure CN122060993A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lithium-ion battery recycling, specifically relating to a process for the recycling of aluminum slag from lithium batteries. Background Technology
[0002] With the increasing severity of global energy shortages and environmental damage, reducing resource consumption and protecting the environment have gradually become a widespread consensus. Lithium-ion batteries, due to their advantages such as high energy density, high voltage, good cycle performance, low self-discharge, and environmental friendliness, are widely used in electric vehicles and various electronic devices, offering a solution to humanity's energy shortage dilemma. Because of their low cost, safety, good thermal stability, and high cycle performance, lithium batteries are widely used in various industries. However, as their lifespan ends, a large number of waste lithium-ion batteries are generated, making research on the recycling of waste lithium-ion batteries extremely urgent.
[0003] Lithium battery recycling generates a large amount of aluminum slag rich in valuable metal powder. This ground aluminum slag can be used as raw material for fireworks and aluminum ingots. Currently, the conventional processing method involves grinding under atmospheric conditions, which produces a large amount of dust and heat. During subsequent storage, the quasi-insulator properties of micron-sized aluminum powder lead to a significant accumulation of static electricity, reaching voltages of tens of thousands of volts, potentially generating sparks and causing explosions. During transportation, the small particle size and large surface area of the aluminum powder increase friction, and the inability to dissipate charge in time can also generate sparks and cause explosions. Since traditional ball milling processes have not completely eliminated the fire risks associated with aluminum powder during grinding, storage, and transportation, there is an urgent need to find a safer process for the treatment, storage, and transportation of aluminum slag. Summary of the Invention
[0004] To address the shortcomings of the existing technology, this invention provides a recycling process for aluminum slag from lithium batteries. The purpose of this process is to safely grind the aluminum slag generated during industrial production, thereby reducing the risk level of the process.
[0005] The specific technical solution is as follows: A recycling process for aluminum slag from lithium batteries includes the following steps: (1) The aluminum slag generated during the industrial production process is first lifted by a hoist to a magnetic separator for demagnetization to obtain magnetically separated aluminum slag; (2) The aluminum slag obtained after magnetic separation in step (1) is added to the mixer at a certain rate and mixed with a certain proportion of fatty acids and activated carbon to obtain a mixture; (3) Add the mixture obtained in step (2) into the grinder for grinding and perform a classification. The large aluminum particles that are intercepted will be returned to the grinder for grinding again. (4) The material that has been classified once in step (3) is classified a second time to obtain black powder and aluminum powder respectively; (5) Press the aluminum powder obtained in step (4) into blocks to prevent aluminum slag from floating on the molten liquid during the smelting process. (6) The aluminum block obtained in step (5) is vacuum melted and cooled to obtain aluminum ingot.
[0006] Furthermore, in step (1), the magnetic field strength of the magnetic separator is 3000~5000Gs.
[0007] Furthermore, in step (2), the mass ratio of the fatty acid, activated carbon, and magnetically separated aluminum slag is (0.1~1):(0.5~3):(1000~1500).
[0008] Furthermore, in step (3), the frequency of the grinding machine is controlled to be 15~50Hz.
[0009] Furthermore, in step (3), the frequency of the first grading is 15~50Hz.
[0010] Furthermore, in step (4), the frequency of the secondary classification is 15~50Hz.
[0011] Furthermore, in step (5), the pressure of the pressure block is controlled at 500~3000kN, and the pressure holding time is 3~15s.
[0012] Furthermore, in step (6), the parameters of the vacuum melting include: temperature 500~1500℃, holding time 1~3h, and vacuum degree <50Pa.
[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: Conventional grinding, lacking any additives to aid grinding, results in highly reactive aluminum powder. Furthermore, the friction between the powder particles during subsequent transportation easily generates static electricity, posing a serious threat to the safety of aluminum powder transport. This invention primarily addresses this by adding fatty acids to prevent friction between aluminum powder particles during transportation and by introducing activated carbon to conduct away static electricity. Through the synergistic effect of fatty acids and activated carbon, the risks associated with the transportation and storage of aluminum powder are reduced.
[0014] Traditional grinding mills use vibrating screens to separate aluminum powder and black powder. This invention uses a two-stage (two-times) grading method to replace the traditional sieving method. The advantage of this method is that the grading frequency is adjustable, which can realize the preparation of aluminum powder with different particle sizes. Moreover, since the entire system is under negative pressure, dust can be reduced compared to the traditional sieving method.
[0015] This invention uses a briquetting process to press aluminum powder into briquettes, and then uses vacuum melting to form aluminum ingots, which can prevent aluminum slag from floating on the surface of the molten liquid during the melting process.
[0016] In summary, this invention provides a method for preventing aluminum slag from igniting during grinding, storage, and transportation. This method can reduce the risks associated with aluminum slag treatment and has certain industrial application prospects. Attached Figure Description
[0017] Figure 1 This is a flowchart of the recycling process for lithium battery aluminum slag in this invention. Detailed Implementation
[0018] The principles and features of the present invention are described below with reference to examples. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. The parts mentioned in the specific embodiments are parts by weight.
[0019] Example 1 A recycling process for aluminum slag from lithium batteries includes the following steps: Waste lithium battery aluminum slag generated during industrial production is fed into a vertical elevator. A magnetic separator with a strength of 3000 Gs separates the ferrous materials from the slag. The qualified slag is then stored in a buffer silo. Fatty acids and activated carbon are added to a mixer and mixed with the magnetically separated aluminum slag in a mass ratio of 0.1:3:1500 to obtain a mixture. This mixture is then ground in a mill at a controlled frequency of 15 Hz. The ground material is then fed into… The first-stage classifier performs a primary classification at a frequency of 35Hz. Large aluminum particles are intercepted by the classifying wheel and returned to the grinder for further grinding. The material passing through the classifying wheel undergoes a secondary classification at a frequency of 15Hz, yielding black powder and aluminum powder. The obtained aluminum powder is then pressed into briquettes, with the pressure controlled at 500kN and the holding time at 3s. Finally, the pressed aluminum briquettes are vacuum-melted using a vacuum melting machine, with the temperature controlled at 500℃, the holding time at 1h, and the vacuum degree at <50Pa. After the melt cools, aluminum ingots are obtained.
[0020] Example 2 A recycling process for aluminum slag from lithium batteries includes the following steps: Waste lithium battery aluminum slag generated during industrial production is fed into a vertical elevator. A magnetic separator with a strength of 3500 Gs separates the ferrous materials from the slag. The qualified slag is then stored in a buffer silo. Fatty acids and activated carbon are added to a mixer and mixed with the magnetically separated aluminum slag at a mass ratio of 0.5:0.5:1200 to obtain a mixture. This mixture is then ground in a grinder at a controlled frequency of 35 Hz. The ground material is then fed into a... The material is first classified by a classifier at a frequency of 15Hz. Large aluminum particles are intercepted by the classifier wheel and returned to the grinder for further grinding. The material passing through the classifier wheel undergoes a second classification at a frequency of 35Hz to obtain black powder and aluminum powder. The obtained aluminum powder is then pressed into briquettes, with the pressure controlled at 3000kN and the holding time at 9s. Finally, the pressed aluminum briquettes are vacuum melted using a vacuum melting machine, with the temperature controlled at 1000℃, the holding time at 1.5h, and the vacuum degree at <50Pa. After the melt cools, aluminum ingots are obtained.
[0021] Example 3 A recycling process for aluminum slag from lithium batteries includes the following steps: Waste lithium battery aluminum slag generated during industrial production is fed into a vertical elevator. A magnetic separator with a strength of 5000 Gs separates the ferrous materials from the slag. The qualified slag is then stored in a buffer silo. Fatty acids and activated carbon are added to a mixer and mixed with the magnetically separated aluminum slag in a mass ratio of 1:1.5:1000 to obtain a mixture. This mixture is then ground in a grinder at a controlled frequency of 50 Hz. The ground material is then fed into a... The material is first classified by a classifier at a frequency of 50Hz. Large aluminum particles are intercepted by the classifier wheel and returned to the grinder for further grinding. The material passing through the classifier wheel undergoes a second classification at a frequency of 50Hz to obtain black powder and aluminum powder. The obtained aluminum powder is then pressed into briquettes, with the pressure controlled at 3000kN and the holding time at 15s. Finally, the pressed aluminum briquettes are vacuum melted using a vacuum melting machine, with the temperature controlled at 1500℃, the holding time at 3h, and the vacuum degree at <50Pa. After the melt is cooled, aluminum ingots are obtained.
[0022] Comparative Example 1 A recycling process for aluminum slag from lithium batteries includes the following steps: Waste lithium battery aluminum slag generated during industrial production is added to a traditional grinder for grinding at a controlled frequency of 15Hz. A large amount of dust is generated during the grinding process. The aluminum powder is then passed through a 150-mesh sieve to obtain black powder and aluminum slag. The aluminum slag is then vacuum smelted at a controlled temperature of 500℃, a holding time of 1 hour, and a vacuum degree of <50Pa. After the melt is cooled, aluminum ingots are obtained.
[0023] Comparative Example 2 A recycling process for aluminum slag from lithium batteries includes the following steps: Waste lithium battery aluminum slag generated during industrial production is mixed with fatty acids at a mass ratio of 1.0:1200 to obtain a mixture. This mixture is then ground in a mill at a controlled frequency of 35Hz. The ground material is then fed into a primary classifier for initial classification at a frequency of 15Hz. Large aluminum particles are intercepted by the classifier wheels and returned to the mill for further grinding. The material passing through the classifier wheels undergoes a second classification at a frequency of 35Hz to obtain black powder and aluminum powder. The resulting aluminum powder is then briquetted at a controlled pressure of 3000kN and a holding time of 9s. Finally, the briquetted aluminum blocks are vacuum-melted in a vacuum melting machine at a controlled temperature of 1000℃, a holding time of 1.5h, and a vacuum degree of <50Pa. After the melt cools, aluminum ingots are obtained.
[0024] Comparative Example 3 A recycling process for aluminum slag from lithium batteries includes the following steps: Waste lithium battery aluminum slag generated during industrial production is mixed with activated carbon at a ratio of 2.5:1000 to obtain a mixture. This mixture is then ground in a mill at a frequency of 50Hz. The ground material is then fed into a primary classifier for initial classification at a frequency of 50Hz. Large aluminum particles are intercepted by the classifier wheels and returned to the mill for further grinding. The material passing through the classifier wheels undergoes a second classification at a frequency of 50Hz to obtain black powder and aluminum powder. The resulting aluminum powder is then briquetted at a pressure of 3000kN and a holding time of 15s. Finally, the briquetted aluminum blocks are vacuum-melted in a vacuum melting machine at a temperature of 1500℃, a holding time of 3 hours, and a vacuum degree of <50Pa. After the melt cools, aluminum ingots are obtained.
[0025] test: The aluminum content in the black powder, aluminum powder, and black powder content after grinding in each embodiment and comparative example, as well as the aluminum content in the dust collection powder, were tested. The test results are shown in Table 1.
[0026] The aluminum grade and aluminum yield of the products after vacuum melting in each embodiment and comparative example were tested, and the test results are shown in Table 2.
[0027] Table 1. Content test data for each example and comparative example.
[0028] Table 2 Vacuum melting conditions and product test data for each embodiment and comparative example.
[0029] As can be seen from the data in Tables 1 and 2, after grinding the aluminum slag in this embodiment of the invention, the aluminum powder contains Al > 85%, indicating high activity and no further impurity removal is required. From the data of vacuum smelting aluminum, the aluminum grade is ≥ 98%, the aluminum yield is ≥ 93.5%, and the formed aluminum ingots can be sold as by-products, which has good economic benefits.
[0030] Comparing the data of the embodiments and Comparative Example 1 in Tables 1 and 2, it can be seen from the data in Table 1 that the conventional grinding in Comparative Example 1, due to the grinding process being exposed to air, resulted in the aluminum slag becoming brittle due to air oxidation, leading to an increase in the aluminum content in the black powder and a decrease in the quality of the aluminum powder. In contrast, the embodiments of the present invention, due to the addition of fatty acids and activated carbon, can encapsulate the aluminum powder during the grinding process and promptly dissipate heat, thus obtaining high-quality aluminum powder. The data in Table 2 shows that the aluminum ingot obtained from the conventional grinding and smelting of Comparative Example 1 had a quality of only 85% and an aluminum yield of only 83%, mainly due to the large-scale oxidation of aluminum caused by conventional grinding.
[0031] Comparing the data from Examples 1 and 2 in Tables 1 and 2, Table 1 shows that adding fatty acids during the grinding process in Comparative Example 2 improved the quality of the ground aluminum powder compared to Comparative Example 1 without added fatty acids. However, compared to Examples 1 with both added fatty acids and activated carbon, the aluminum quality decreased. This indicates that the coupling effect of fatty acids and activated carbon during the grinding process is necessary to obtain high-quality aluminum powder. Table 2 shows that adding fatty acids during grinding in Comparative Example 2 resulted in aluminum ingots with a quality of only 90.5% and an aluminum yield of only 80%. This demonstrates that simply adding fatty acids cannot produce high-quality aluminum ingots; both fatty acids and activated carbon must be added simultaneously.
[0032] Comparing the data from Examples 1 and 3 in Tables 1 and 2, Table 1 shows that adding activated carbon during the grinding process in Comparative Example 3 improved the quality of the ground aluminum powder compared to Comparative Example 1 without activated carbon. However, compared to the examples with both fatty acids and activated carbon, the aluminum quality decreased. This further illustrates that the coupling effect of fatty acids and activated carbon during the grinding process is necessary to obtain high-quality aluminum powder. Table 2 shows that adding activated carbon during grinding in Comparative Example 3 resulted in aluminum ingots with only 90% quality and an aluminum yield of only 85%. This demonstrates that simply adding activated carbon cannot produce high-quality aluminum ingots, further indicating that fatty acids and activated carbon need to be added simultaneously.
[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A recycling process for aluminum slag from lithium batteries, characterized in that, Includes the following steps: (1) The aluminum slag generated during the industrial production process is first lifted by a hoist to a magnetic separator for demagnetization to obtain magnetically separated aluminum slag; (2) Add the magnetically separated aluminum slag obtained in step (1) into a mixer and mix it with fatty acids and activated carbon to obtain a mixture; (3) Add the mixture obtained in step (2) into the grinder for grinding and perform a classification. The large aluminum particles that are intercepted will be returned to the grinder for grinding again. (4) The material that has been classified once in step (3) is classified a second time to obtain black powder and aluminum powder respectively; (5) Press the aluminum powder obtained in step (4) into blocks to obtain aluminum blocks; (6) The aluminum block obtained in step (5) is vacuum melted and cooled to obtain aluminum ingot.
2. The recycling process for lithium battery aluminum slag according to claim 1, characterized in that, In step (2), the mass ratio of fatty acid, activated carbon, and magnetically separated aluminum slag is (0.1~1):(0.5~3):(1000~1500).
3. The recycling process for lithium battery aluminum slag according to claim 1, characterized in that, In step (1), the magnetic field strength of the magnetic separator is 3000~5000Gs.
4. The recycling process for lithium battery aluminum slag according to claim 1, characterized in that, In step (3), the frequency of the grinding machine is controlled to be 15~50Hz.
5. The recycling process for lithium battery aluminum slag according to claim 1, characterized in that, In step (3), the frequency of the first grading is 15~50Hz.
6. The recycling process for lithium battery aluminum slag according to claim 1, characterized in that, In step (4), the frequency of the secondary classification is 15~50Hz.
7. The recycling process for lithium battery aluminum slag according to claim 1, characterized in that, In step (5), the pressure of the pressure block is controlled at 500~3000kN and the pressure holding time is 3~15s.
8. The recycling process for lithium battery aluminum slag according to claim 1, characterized in that, In step (6), the parameters of the vacuum melting include: temperature 500~1500℃ and holding time 1~3h.
9. The recycling process for lithium battery aluminum slag according to claim 8, characterized in that, In step (6), the parameters for vacuum melting also include: vacuum degree <50Pa.