Aluminum product waste recovery method and system

Abstract

The invention relates to the technical field of recycling, and discloses an aluminum product waste recycling method and system. And non-aluminum impurities in the aluminum product waste are removed, and the treated aluminum product waste is crushed into a plurality of sheet-shaped aluminum waste. And the sheet-shaped aluminum waste materials are placed in an oxygen-free environment to be heated for preset time, so that coatings on the surfaces of the sheet-shaped aluminum waste materials are pyrolyzed, the sheet-shaped aluminum waste materials without the coatings and pyrolysis gas are obtained, and the pyrolysis gas is collected and purified. By means of the aluminum product waste recycling method, the sheet-shaped aluminum waste is heated in the oxygen-free environment, the coating on the surface of the sheet-shaped aluminum waste is pyrolyzed, and meanwhile pyrolysis gas generated by pyrolysis of the coating is collected and purified. The aluminum can be prevented from being oxidized, the recovery rate is increased, and pyrolysis gas generated by coating pyrolysis can be prevented from polluting the environment.

Description

Technical Field

[0001] This application relates to the field of recycling technology, specifically to a method and system for recycling aluminum product waste. Background Technology

[0002] Aluminum is a metal that can be recycled indefinitely; compared to producing primary aluminum, recycling aluminum can save approximately 95% of the energy. Aluminum is widely used in building curtain walls, transportation, packaging containers, and electronics. These aluminum products generate a large amount of waste after use or during processing. Therefore, the recycling and reuse of this aluminum waste is particularly important.

[0003] Traditional aluminum scrap recycling methods involve directly melting various aluminum scraps. However, because aluminum scraps often have paint, fluorocarbon coatings, plastic films (such as advertising boards), or anodized layers on their surfaces, these materials burn during high-temperature melting, producing large amounts of harmful gases that pollute the environment. Furthermore, direct melting causes aluminum oxidation, resulting in low recycling rates.

[0004] Therefore, how to solve or improve the problems of environmental pollution caused by harmful gases generated during the recycling of aluminum waste and the low aluminum recovery rate in related technologies has become an important technical problem to be solved by those skilled in the art. Summary of the Invention

[0005] This application provides a method and system for recycling aluminum product waste to solve or improve the problems of generating harmful gases and low recycling rates during the recycling of aluminum product waste.

[0006] In a first aspect, this application provides a method for recycling aluminum scrap, comprising: Step S1: Remove non-aluminum impurities from aluminum scrap; Step S2: Crush the aluminum scrap after step S1 into multiple sheet-like aluminum scraps; Step S3: Place the sheet aluminum scrap in an oxygen-free environment and heat for a preset time to pyrolyze the coating on the surface of each sheet aluminum scrap, and obtain the coated sheet aluminum scrap and pyrolysis gas. Step S4: Collect the pyrolysis gas and purify it.

[0007] In an optional implementation, after step S4, the method further includes: Step S5: The decoated sheet aluminum scrap is sorted according to alloy type; Step S6: Melt the sheet aluminum scraps of different alloy types separately to obtain different types of molten aluminum.

[0008] In one optional implementation, prior to step S5, the method further includes: Step S4a: Physically screen the decoated sheet aluminum waste obtained in step S3 to remove pyrolysis residues and impurities of foreign metals.

[0009] In one optional implementation, step S6 includes: Step S61: Place the sheet aluminum scraps of different alloy types into different furnaces for smelting; Step S62: Add a covering agent to each of the furnaces, the covering agent being used to prevent the flaky aluminum scrap from oxidizing; Step S63: Add the corresponding refining agent to each of the furnaces. The refining agent is used to remove non-aluminum metal elements from the sheet aluminum scrap.

[0010] In an optional implementation, step S6 further includes: Step S64: Stir or inject inert gas into each of the furnaces.

[0011] In one optional implementation, step S3 includes: The sheet-like aluminum scrap is placed in an oxygen-free environment at 450°C to 600°C and kept at that temperature for 30 to 90 minutes.

[0012] In one alternative embodiment, the sheet-like aluminum scrap has a characteristic size of 5 cm to 15 cm.

[0013] In one optional implementation, after step S6, the method further includes: Step S7: Cast the molten aluminum of different alloy types into aluminum ingots respectively.

[0014] Secondly, this application also provides an aluminum product waste recycling system, applicable to any of the aluminum product waste recycling methods described above, including: The sorting table is used to sort and remove non-aluminum impurities from aluminum product waste. A crusher is used to crush the sorted aluminum scrap into multiple sheet-like aluminum scraps. An oxygen-free pyrolysis furnace is used to heat the aforementioned sheet-like aluminum waste in an oxygen-free environment for a preset time. An exhaust gas purification component is used to purify the volatile gases generated by the pyrolysis of the coating.

[0015] In one alternative implementation, it further includes: The sorting unit is used to remove impurities from the decoated sheet aluminum scrap and to sort the decoated sheet aluminum scrap according to alloy type. and / or a smelting unit for smelting the sheet aluminum scrap of different alloy types separately.

[0016] This application provides a method for recycling aluminum product scrap. When recycling aluminum product scrap mixed with aluminum of various specifications, non-aluminum impurities are first removed from the scrap. Then, the scrap, after removing non-aluminum impurities, is crushed into multiple sheet-like aluminum scraps. These sheet-like scraps are then heated in an oxygen-free environment for a preset time to pyrolyze the coating on their surface, resulting in decoated sheet-like aluminum scrap and pyrolysis gas. The pyrolysis gas generated after the coating on the sheet-like aluminum scrap is then collected and purified. Heating the sheet-like aluminum scrap in an oxygen-free environment, simultaneously pyrolyzing the coating and collecting and purifying the resulting pyrolysis gas, not only prevents aluminum oxidation and improves the recovery rate but also avoids environmental pollution from the pyrolysis gas generated by the coating. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this application, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating a method for recycling aluminum scrap according to an embodiment of this application; Figure 2 This is a flowchart illustrating another method for recycling aluminum scrap according to an embodiment of this application; Figure 3 This is a flowchart illustrating another method for recycling aluminum scrap according to an embodiment of this application; Figure 4 This is a flowchart illustrating another method for recycling aluminum scrap according to an embodiment of this application; Figure 5 This is a schematic diagram of an aluminum product waste recycling system according to an embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: 1. Sorting table; 2. Crusher; 3. Anaerobic pyrolysis furnace; 4. Waste gas purification components; 5. Sorting unit; 6. Smelting unit; 7. Casting unit. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The following is combined Figures 1 to 5 This describes an embodiment of the present application.

[0022] According to embodiments of this application, one aspect provides a method for recycling aluminum product waste, such as... Figure 1 and Figure 3 As shown, it includes: Step S1: Remove non-aluminum impurities from aluminum scrap; Step S2: Crush the aluminum scrap processed in step S1 into multiple sheet-like aluminum scraps; Step S3: Place the sheet aluminum scrap in an oxygen-free environment and heat for a preset time to pyrolyze the coating on the surface of each sheet aluminum scrap, and obtain the coated sheet aluminum scrap and pyrolysis gas. Step S4: Collect the pyrolysis gas and purify it.

[0023] When recycling aluminum product waste mixed with aluminum of various specifications, non-aluminum impurities, including iron products and plastics, are removed first to increase the proportion of aluminum in the aluminum product waste.

[0024] Then, the aluminum scrap, after removing non-aluminum impurities, is crushed into multiple sheet-like aluminum scraps to increase the specific surface area and facilitate subsequent processing.

[0025] The sheet aluminum scrap is then placed in an oxygen-free environment and heated for a preset time to pyrolyze the coating on its surface, resulting in coated sheet aluminum scrap and pyrolysis gas. Because the sheet aluminum scrap is heated in an oxygen-free environment, aluminum oxidation is effectively inhibited, thus avoiding aluminum oxidation loss and improving the aluminum recovery rate.

[0026] Then, the pyrolysis gas generated after the coating on the surface of the sheet aluminum waste is pyrolyzed is collected and purified to prevent the pyrolysis gas from being discharged and polluting the environment.

[0027] This method heats sheet-like aluminum scrap in an oxygen-free environment, pyrolyzing the coating on the surface of the scrap while simultaneously collecting and purifying the pyrolysis gas generated. This not only prevents aluminum oxidation, thus increasing the recovery rate, but also avoids environmental pollution from the pyrolysis gas produced by the coating pyrolysis.

[0028] Specifically, step S1 can be implemented through sorting table 1, where aluminum waste is placed on sorting table 1, and non-aluminum impurities in the aluminum waste on sorting table 1 are removed manually.

[0029] Step S2 can be implemented by crusher 2. After the aluminum scrap is manually sorted, it is put into crusher 2, which can crush the aluminum scrap into multiple sheet-like aluminum scraps.

[0030] Step S3 can be implemented by an oxygen-free pyrolysis furnace 3. The sheet aluminum waste is placed into the oxygen-free pyrolysis furnace 3, and the sheet aluminum waste is heated in an oxygen-free environment for a preset time to pyrolyze the coating on the surface of each sheet aluminum waste, so as to obtain sheet aluminum waste with the coating removed and pyrolysis gas.

[0031] Step S4 can be implemented using the exhaust gas purification component 4, which collects the pyrolysis gas generated from the pyrolysis of the coating on the surface of the sheet aluminum scrap into the exhaust gas purification component 4, and uses the exhaust gas purification component 4 to purify the volatile gases generated from the pyrolysis of the coating. The exhaust gas purification component 4 can be a corresponding exhaust gas treatment device.

[0032] In one embodiment, such as Figure 2 and Figure 3 As shown, after step S3, the following steps are also included: Step S5: Sort the decoated sheet aluminum scrap according to the alloy type; Step S6: Melt the sheet aluminum scraps of different alloy types separately to obtain different types of molten aluminum.

[0033] Flake aluminum scrap is heated in an oxygen-free environment for a preset time to pyrolyze the coating on the surface of each flake aluminum scrap, resulting in decoated flake aluminum scrap and pyrolysis gas. The pyrolysis gas is then collected and purified.

[0034] After this, the coated sheet aluminum scrap is sorted according to alloy type to obtain sheet aluminum scrap of different alloy types. The different alloy types of aluminum include 1 series (pure aluminum), 2 series (aluminum-copper alloy), 3 series (aluminum-manganese alloy), 4 series (aluminum-silicon alloy) and 5 series (aluminum-magnesium alloy), etc.

[0035] Different types of aluminum scrap with different alloys are smelted separately to obtain different types of molten aluminum. For example, the aluminum scrap with different alloys can be sorted into pure aluminum, aluminum-manganese alloy, and aluminum-magnesium alloy. Then, the pure aluminum scrap is smelted to obtain pure aluminum molten aluminum; the aluminum-manganese alloy scrap is smelted to obtain aluminum-manganese alloy molten aluminum; and the aluminum-magnesium alloy scrap is smelted to obtain aluminum-magnesium alloy molten aluminum.

[0036] In this way, different types of molten aluminum can be cast separately to obtain different types of aluminum raw materials, which can be reused according to needs, improving the quality of recycled aluminum raw materials and avoiding the situation where aluminum raw materials are mixed with various types of aluminum and can only be used as low-grade cast aluminum alloys.

[0037] Step S5 can be implemented by sorting unit 5, which includes a near-infrared photoelectric sorter. The decoated sheet aluminum scrap passes through the near-infrared photoelectric sorter during the conveying process. The near-infrared photoelectric sorter can sort the decoated sheet aluminum scrap according to the type of aluminum alloy to obtain different types of sheet aluminum scrap.

[0038] Step S6 can be implemented through smelting unit 6, which includes a furnace, which can be a reverberatory furnace. Different types of aluminum scrap are placed into their respective reverberatory furnaces for smelting to obtain different types of molten aluminum.

[0039] In one embodiment, such as Figure 3 As shown, before step S5, the following steps are also included: Step S4a: Physically screen the decoated sheet aluminum scrap obtained in step S3 to remove pyrolysis residues and impurities of foreign metals.

[0040] Flake aluminum scrap is heated in an oxygen-free environment for a preset time to pyrolyze the coating on the surface of each flake aluminum scrap, resulting in decoated flake aluminum scrap and pyrolysis gas. The pyrolysis gas is then collected and purified.

[0041] Following this, the decoated sheet aluminum scrap is physically screened to remove pyrolysis residues and impurities. This further removes impurities from the sheet aluminum scrap and increases the aluminum content.

[0042] The pyrolysis residue refers to the product generated after the coating is pyrolyzed and pyrolysis gas is produced, while the heterometal refers to a metal that does not contain aluminum.

[0043] It is worth noting that when physically screening the uncoated sheet aluminum scrap, non-metallic impurities that may be mixed in, such as stones and glass, can also be screened out.

[0044] Step S4 can be implemented by sorting unit 5, which includes an eddy current separator. The decoated sheet aluminum waste passes through the eddy current separator during the conveying process. The eddy current separator can physically screen the decoated sheet aluminum waste to remove pyrolysis residues and mixed foreign metals.

[0045] In one embodiment, such as Figure 4 As shown, step S6 includes: Step S61: Place the sheet aluminum scraps of different alloy types into different furnaces for smelting; Step S62: Add a covering agent to each furnace to prevent the flaky aluminum scrap from oxidizing; Step S63: Add the corresponding refining agent to each furnace. The refining agent is used to remove non-aluminum metal elements from the sheet aluminum scrap.

[0046] When melting sheet aluminum scrap of different alloy types separately, the sheet aluminum scrap of different alloy types is placed into different furnaces for melting, that is, the sheet aluminum scrap corresponds to the furnace one by one, and each furnace is filled with a corresponding type of sheet aluminum scrap for melting.

[0047] During smelting in each furnace, a covering agent is added to prevent the oxidation of the flaky aluminum scrap. This avoids aluminum oxidation loss and improves the aluminum recovery rate. The covering agent can be a mixture of NaCl and KCl.

[0048] During the smelting process in each furnace, a corresponding refining agent is added to each furnace. This refining agent is used to remove non-aluminum metal elements from the flaky aluminum scrap. This process purifies the aluminum to a certain extent, increasing the purity of the resulting molten aluminum and thus improving its quality.

[0049] For example, refining agents can be composed of potassium fluorotitanate and sodium nitrate in a certain proportion, which can effectively remove trace amounts of harmful impurities such as magnesium from molten aluminum, while promoting the addition of titanium to refine the grains.

[0050] In one embodiment, such as Figure 4 As shown, step S6 further includes: Step S64: Stir or inject inert gas into each furnace.

[0051] While smelting in each furnace, inert gas is stirred or injected into each furnace to make the aluminum solution obtained from smelting more uniform in composition and to effectively remove hydrogen and inclusions.

[0052] The inert gas can be argon. To stir the contents of the furnace, a stirring shaft can be installed inside the furnace, and blades can be installed on the stirring shaft. The stirring shaft is driven to rotate by a motor to stir the contents of the furnace.

[0053] In one embodiment, step S3 includes: placing the sheet aluminum scrap in an oxygen-free environment at 450°C to 600°C and holding it at that temperature for 30 to 90 minutes.

[0054] When heating sheet aluminum scrap, the sheet aluminum scrap is placed in an oxygen-free environment at 450°C to 600°C. The temperature of the oxygen-free environment can be any temperature among 450°C, 500°C, 550°C, 580°C, and 600°C.

[0055] When the temperature in an oxygen-free environment is below 450℃, the pyrolysis effect of the coating is poor, and the coating cannot be effectively pyrolyzed. When the temperature in an oxygen-free environment is above 600℃, the aluminum element in the sheet aluminum scrap is prone to react with other elements, resulting in the loss of aluminum element.

[0056] After placing the sheet aluminum scrap in an oxygen-free environment at 450℃ to 600℃, hold it at that temperature for 30 to 90 minutes. The holding time can be any of 30 minutes, 45 minutes, 60 minutes, 75 minutes, and 90 minutes.

[0057] When the holding time is less than 30 minutes, the pyrolysis effect of the coating is poor, and the coating cannot be effectively pyrolyzed. When the holding time is greater than 90 minutes, the aluminum element in the sheet aluminum scrap is prone to react with other elements, resulting in the loss of aluminum element.

[0058] In one embodiment, the characteristic dimensions of the sheet aluminum scrap are 5 cm to 15 cm. The characteristic dimensions of the sheet aluminum scrap can be the width of the sheet aluminum scrap.

[0059] When breaking aluminum scrap after removing non-aluminum impurities into multiple sheet-shaped aluminum scraps, the width of the sheet-shaped aluminum scraps is controlled between 5 cm and 15 cm, where the width of the sheet-shaped aluminum scraps can be any size among 5 cm, 8 cm, 10 cm, 12 cm and 15 cm.

[0060] When the width of the sheet aluminum scrap is greater than 15 cm, the degree of heating is relatively small, resulting in poor pyrolysis of the coating and ineffective pyrolysis of the coating. When the width of the sheet aluminum scrap is less than 5 cm, the degree of heating is too large, and the aluminum element in the sheet aluminum scrap is prone to react with other elements, leading to the loss of aluminum element.

[0061] The characteristic dimension of sheet aluminum scrap can be either the diagonal dimension of the sheet aluminum scrap or the minimum dimension of the sheet aluminum scrap.

[0062] In one embodiment, such as Figure 3 As shown, after step S6, the following is also included: Step S7: Cast the molten aluminum of different alloy types into aluminum ingots.

[0063] Different types of aluminum scrap are melted separately to obtain different types of molten aluminum. These molten aluminum materials are then cast into aluminum ingots, resulting in aluminum ingots of different alloy types that can be reused as needed.

[0064] Step S7 can be implemented using a continuous casting machine, in which molten aluminum of different alloy types is fed into the continuous casting machine to be cast into aluminum ingots.

[0065] In one combined embodiment, waste fluorocarbon-coated aluminum sheets for construction (primarily 3003 alloy) and waste film-coated aluminum sheets for advertising (primarily 1100 alloy) are collected.

[0066] Waste aluminum products are formed by mixing waste fluorocarbon-coated aluminum sheets used in construction and waste aluminum sheets used in advertising.

[0067] First, manual sorting is used to remove non-aluminum impurities from aluminum product waste, thereby increasing the proportion of aluminum in the aluminum product waste.

[0068] Then, the aluminum scrap after removing non-aluminum impurities is crushed into multiple 10-centimeter-wide sheet aluminum scraps using the crusher 2 to increase the specific surface area and facilitate subsequent processing.

[0069] The sheet aluminum scrap is then placed in an oxygen-free pyrolysis furnace 3, where the temperature is increased to 550°C at a rate of 10°C / min and held for 60 minutes for a preset heating time. This process pyrolyzes the coating on the surface of the sheet aluminum scrap, yielding coated sheet aluminum scrap and pyrolysis gas. Because the sheet aluminum scrap is heated in an oxygen-free environment, aluminum oxidation is effectively inhibited, thus preventing aluminum loss due to oxidation and improving the aluminum recovery rate.

[0070] Then, the pyrolysis gas generated after the coating on the surface of the sheet aluminum waste is pyrolyzed is collected into the exhaust gas purification component 4. The exhaust gas purification component 4 is used to purify the pyrolysis gas to prevent the pyrolysis gas from being discharged and polluting the environment.

[0071] The sheet aluminum scrap is then cooled to below 80°C and conveyed, passing through an eddy current separator during transport to remove approximately 1% of pyrolysis residues and impurities. This further removes impurities from the sheet aluminum scrap, increasing the aluminum content.

[0072] Then, during the conveying process, the sheet aluminum scrap passes through a near-infrared photoelectric sorting machine. Using a preset model, the 1100 alloy sheet aluminum scrap and the 3003 alloy sheet aluminum scrap are sorted into different bins with a sorting accuracy of over 95%.

[0073] The sorted 3003 alloy sheet aluminum scrap was fed into a 10-ton reverberatory furnace for melting. After melting, a covering agent was added, and a refining agent consisting of 90% KCl and 10% Na3AlF6 was sprayed in. Argon gas was then introduced for refining for 15 minutes. After settling and slag removal, samples were taken for composition analysis, and minor adjustments were made based on the results. Finally, the molten aluminum was cast into 3003 recycled aluminum ingots.

[0074] Testing revealed that the main elemental composition of the recycled aluminum ingot met the requirements of GB / T3190 for 3003 alloy, with low levels of impurities such as Fe and Si, making it suitable for rolling new aluminum sheets.

[0075] The sorted 1100 alloy can be directly fed into a reverberatory furnace for melting. After melting, a covering agent is added, and a refining agent consisting of 90% KCl and 10% Na3AlF6 is sprayed in. Argon gas is then introduced for refining for 15 minutes. After settling and slag removal, samples are taken for composition analysis, and fine adjustments are made based on the results. Finally, the molten aluminum is cast into 1100 recycled aluminum ingots.

[0076] Testing revealed that the main elemental composition of the recycled aluminum ingot met the requirements of GB / T3190 for 1100 alloy and could be used to roll new aluminum sheets.

[0077] According to embodiments of this application, another aspect provides an aluminum product waste recycling system applicable to any of the above-described aluminum product waste recycling methods. For example... Figure 5 As shown, the aluminum product scrap recycling system includes a sorting table 1, a crusher 2, an anaerobic pyrolysis furnace 3, and a waste gas purification component 4. The sorting table 1 is used to sort and remove non-aluminum impurities from the aluminum product scrap. The crusher 2 is used to crush the sorted aluminum product scrap into multiple sheet-like aluminum scraps. The anaerobic pyrolysis furnace 3 is used to heat each sheet-like aluminum scrap in an oxygen-free environment for a preset time. The waste gas purification component 4 is used to purify and treat the volatile gases generated during coating pyrolysis.

[0078] When recycling aluminum product waste mixed with aluminum of various specifications, the aluminum product waste is first placed on sorting table 1, and non-aluminum impurities in the aluminum product waste are removed manually to increase the proportion of aluminum in the aluminum product waste.

[0079] Then, the manually sorted aluminum scrap is put into crusher 2. Crusher 2 is used to crush the aluminum scrap after removing non-aluminum impurities into multiple sheet-like aluminum scraps to increase the specific surface area and facilitate subsequent processing.

[0080] The sheet aluminum scrap is then placed in an oxygen-free pyrolysis furnace 3, where it is heated for a preset time in an oxygen-free environment to pyrolyze the coating on its surface, resulting in coated sheet aluminum scrap and pyrolysis gas. Because the sheet aluminum scrap is heated in an oxygen-free environment, aluminum oxidation is effectively inhibited, thus preventing aluminum loss due to oxidation and improving the aluminum recovery rate.

[0081] Then, the pyrolysis gas generated after the coating on the surface of the sheet aluminum waste is pyrolyzed is collected into the waste gas purification component 4 and purified using the waste gas purification component 4 to prevent the pyrolysis gas from being discharged and polluting the environment.

[0082] The pyrolysis gas can be treated by rapid cooling and alkaline spraying through the waste gas purification component 4.

[0083] In one embodiment, such as Figure 5As shown, the aluminum product waste recycling system also includes a sorting unit 5, which is used to remove impurities from the decoated sheet aluminum waste and to sort the decoated sheet aluminum waste according to the alloy type.

[0084] The sorting unit 5 includes an eddy current separator and a near-infrared photoelectric separator.

[0085] Flake aluminum scrap is heated in an oxygen-free environment for a preset time to pyrolyze the coating on the surface of each flake aluminum scrap, resulting in decoated flake aluminum scrap and pyrolysis gas. The pyrolysis gas is then collected and purified.

[0086] Following this, the decoated sheet aluminum scrap passes through an eddy current separator during transport. The eddy current separator physically screens the decoated sheet aluminum scrap, removing pyrolysis residues and impurities such as foreign metals. This further removes impurities from the sheet aluminum scrap and increases the aluminum content.

[0087] Then, the sheet aluminum scrap passes through a near-infrared photoelectric sorter during the conveying process. The near-infrared photoelectric sorter can sort the decoated sheet aluminum scrap according to the type of aluminum alloy, obtaining sheet aluminum scrap of different alloy types.

[0088] In one embodiment, such as Figure 5 As shown, the aluminum product waste recycling system also includes a smelting unit 6, which is used to smelt sheet aluminum waste of different alloy types separately.

[0089] The smelting unit 6 includes a furnace, which can be a reverberatory furnace.

[0090] In some embodiments, such as Figure 5 As shown, the aluminum scrap recycling system includes a sorting unit 5 and a smelting unit 6. Different alloy types of sheet aluminum scrap are smelted separately in the smelting unit 6 to obtain different types of molten aluminum. After casting the different types of molten aluminum separately, different types of aluminum raw materials are obtained, which can be reused according to needs. This improves the quality of recycled aluminum raw materials and avoids the situation where aluminum raw materials are mixed with various types of aluminum, preventing the use of only low-grade cast aluminum alloys.

[0091] In one embodiment, such as Figure 5 As shown, the aluminum product waste recycling system also includes a casting unit 7, which is used to cast molten aluminum into aluminum ingots. The casting unit 7 can be a continuous casting machine.

[0092] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by this application.

Claims

1. A method for recycling aluminum scrap, characterized in that, include: Step S1: Remove non-aluminum impurities from aluminum scrap; Step S2: Crush the aluminum scrap after step S1 into multiple sheet-like aluminum scraps; Step S3: Place the sheet aluminum scrap in an oxygen-free environment and heat for a preset time to pyrolyze the coating on the surface of each sheet aluminum scrap, and obtain the coated sheet aluminum scrap and pyrolysis gas. Step S4: Collect the pyrolysis gas and purify it.

2. The method for recycling aluminum waste according to claim 1, characterized in that, After step S4, the method further includes: Step S5: The decoated sheet aluminum scrap is sorted according to alloy type; Step S6: Melt the sheet aluminum scraps of different alloy types separately to obtain different types of molten aluminum.

3. The method for recycling aluminum product waste according to claim 2, characterized in that, Before step S5, the method further includes: Step S4a: Physically screen the decoated sheet aluminum scrap obtained in step S3 to remove pyrolysis residues and impurities of foreign metals.

4. The method for recycling aluminum product waste according to claim 2, characterized in that, Step S6 includes: Step S61: Place the sheet aluminum scraps of different alloy types into different furnaces for smelting; Step S62: Add a covering agent to each of the furnaces, the covering agent being used to prevent the flaky aluminum scrap from oxidizing; Step S63: Add the corresponding refining agent to each of the furnaces. The refining agent is used to remove non-aluminum metal elements from the sheet aluminum scrap.

5. The method for recycling aluminum waste according to claim 4, characterized in that, Step S6 further includes: Step S64: Stir or inject inert gas into each of the furnaces.

6. The method for recycling aluminum scrap according to claim 1, characterized in that, Step S3 includes: The sheet-like aluminum scrap is placed in an oxygen-free environment at 450°C to 600°C and kept at that temperature for 30 to 90 minutes.

7. The method for recycling aluminum scrap according to claim 1, characterized in that, The characteristic size of the sheet-like aluminum scrap is 5 cm to 15 cm.

8. The method for recycling aluminum waste according to claim 2, characterized in that, After step S6, the method further includes: Step S7: Cast the molten aluminum of different alloy types into aluminum ingots respectively.

9. A waste aluminum recycling system, characterized in that, The method for recycling aluminum scrap according to any one of claims 1-8 includes: Sorting table (1) is used to sort and remove non-aluminum impurities from aluminum product waste; Crusher (2) is used to crush the sorted aluminum scrap into multiple sheet-like aluminum scraps; An oxygen-free pyrolysis furnace (3) is used to heat each of the sheet aluminum scraps in an oxygen-free environment for a preset time. The exhaust gas purification component (4) is used to purify the volatile gases generated by the pyrolysis of the coating.

10. The aluminum product waste recycling system according to claim 9, characterized in that, Also includes: The sorting unit (5) is used to remove impurities from the decoated sheet aluminum waste and to sort the decoated sheet aluminum waste according to the alloy type. and / or smelting unit (6), for smelting the sheet aluminum scrap of different alloy types separately.

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