Method for recycling valuable metals in aluminum ash of secondary aluminum based on physical separation

Abstract

The invention relates to the technical field of metal recovery, in particular to a secondary aluminum ash valuable metal recovery method based on physical separation, which comprises the following steps: primarily crushing aluminum ash by using a crusher to enable the granularity to be uniform, grading the crushed aluminum ash by using a screening machine according to different granularities, and removing overlarge or oversmall particles; carrying out magnetic separation on the screened aluminum ash slag by using a magnetic separator to separate out ferromagnetic substances in the aluminum ash slag; the hot aluminum ash slag is added into a hot aluminum ash presser, a pressing aid comprising metal silicon powder, silica fume and potassium chloride is added, and molten aluminum is extruded out by applying static pressure or dynamic pressure. The method depends on physical means for separation and recovery, does not generate harmful waste liquid and waste gas, is environment-friendly, and is lower in energy consumption and favorable for reducing the production cost compared with pyrometallurgy and a physical separation method.

Description

Technical Field

[0001] The present invention relates to the technical field of metal recovery, and in particular to a method for recovering valuable metals from recycled aluminum ash slag based on physical separation. Background Art

[0002] Recycled aluminum aluminum ash slag is the waste generated in the process of aluminum recycling, mainly from the smelting, processing and treatment of waste aluminum products. These ash slags contain not only aluminum metal that has not been fully recovered, but also other valuable metals such as iron, silicon, etc., as well as non-metallic oxides and impurities. Due to the limited aluminum resources and the importance of recycled aluminum, the effective recovery and utilization of valuable metals in aluminum ash slag has significant economic and environmental significance. Because aluminum is a precious metal resource, by recovering the valuable metals in aluminum ash slag, the mining of primary aluminum ore can be reduced, thereby saving natural resources. Moreover, if aluminum ash slag is not properly handled, it may cause pollution to the environment. By recovering the valuable metals in it, the discharge of waste can be reduced and the risk of environmental pollution can be reduced. Therefore, the recovered valuable metals can be used as raw materials and put into production again, reducing production costs and improving economic benefits.

[0003] However, in general, traditional methods for recovering valuable metals from recycled aluminum ash mainly include chemical methods and pyrometallurgy, etc. Valuable metals are extracted by reacting chemical reagents with metals in aluminum ash, but this method may produce a large amount of waste liquid and waste gas, causing secondary pollution to the environment. Aluminum ash is smelted at high temperature and valuable metals are separated through physical and chemical reactions during the smelting process, but pyrometallurgy has high energy consumption and may produce harmful gases and slag, causing damage to the environment and equipment.

[0004] Based on this, the present invention provides a method for recovering valuable metals from regenerated aluminum ash slag based on physical separation to solve the technical problems raised above. Summary of the invention

[0005] The purpose of the present invention is to provide a method for recovering valuable metals from recycled aluminum ash slag based on physical separation. The prepared high-strength metal connector material not only has good mechanical properties, but also has excellent corrosion resistance, effectively ensuring its quality.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention proposes a method for recovering valuable metals from aluminum ash slag based on physical separation, comprising the following steps:

[0008] S1. Use a crusher to preliminarily crush the aluminum ash slag to make it uniform in particle size for subsequent processing, and use a screening machine to classify the crushed aluminum ash slag according to different particle sizes to remove oversized or undersized particles;

[0009] S2. Using a magnetic separator to magnetically separate the sieved aluminum ash to separate the ferromagnetic substances, including iron filings;

[0010] S3. The hot aluminum ash slag is added to the hot aluminum ash press and a pressing aid including metallic silicon powder, silicon ash and potassium chloride is added, and the molten aluminum is squeezed out by applying static or dynamic pressure;

[0011] S4. Purging the aluminum liquid obtained by pressing with argon gas to protect the aluminum liquid surface from the formation of an aluminum oxide film, reduce its fluidity, and reduce the gas content in the aluminum liquid;

[0012] S5. Add the cold aluminum slag after pressing into the smelting furnace, cover it with a salt separator for smelting and aluminum extraction, the salt separator is one of potassium chloride or sodium chloride, and the smelting temperature is 650°C-800°C to maximize aluminum melting and prevent oxidation;

[0013] S6. The hot salt slag obtained by smelting is water-cooled for 3-8 minutes. The temperature of the salt slag after water cooling is controlled at 100-150°C. The water-cooled salt slag is dissociated using a dissociator to obtain cold ash slag;

[0014] S7. The cold ash is vibrated and screened to obtain materials of different particle sizes, and the screened materials are sent to a ball mill for grinding to deform the metallic aluminum and refine the inorganic alumina;

[0015] S8. After grinding, the material is graded and screened according to its particle size and density characteristics to separate metallic aluminum and secondary aluminum ash fine powder;

[0016] S9. Collect the separated aluminum metal and use it for smelting or as raw material for other aluminum products, so as to achieve comprehensive utilization in multiple ways.

[0017] Preferably, the implementation steps of the preliminary crushing and screening of aluminum ash slag in step S1 are:

[0018] S1.1. Perform preliminary crushing by using a jaw crusher or hammer crusher at an operating temperature of 15-30°C and adjusting the crushing ratio to 2-4 according to the hardness and particle size of the aluminum ash;

[0019] S1.2. Use a vibrating screen to screen and grade the crushed aluminum ash slag. Select a screen aperture of 5-10mm according to the target particle size and set the vibration frequency to 15-25Hz to ensure uniform grading of the material.

[0020] Preferably, the implementation steps of magnetic separation of ferromagnetic substances in step S2 are:

[0021] S2.1. Under normal temperature operating environment, the screened aluminum ash slag is sent to the magnetic separator, and the magnetic field strength is adjusted to 0.5-1.5T according to the content of ferromagnetic substances;

[0022] S2.2. Control the speed of materials passing through the magnetic separator to 0.5-1.5m / s to ensure that ferromagnetic materials are fully separated.

[0023] Preferably, the implementation steps of extracting molten aluminum from hot aluminum ash slag in step S3 are:

[0024] S3.1. Adding hot aluminum ash slag into a hot aluminum ash press at an operating temperature of 600-800°C;

[0025] S3.2. According to the composition of aluminum ash, add 1-5% of metallic silicon powder, silicon ash, and potassium chloride as a pressing aid;

[0026] S3.3. Apply static or dynamic pressure of 5-20MPa, and the pressing time is adjusted to 2-10min according to the outflow of molten aluminum.

[0027] Preferably, the implementation steps of the step S4 of purging the aluminum liquid with argon are:

[0028] S4.1. Use an argon purge device to evenly purge argon on the surface of the aluminum liquid. The argon flow rate is adjusted to 1-5L / min according to the surface area of ​​the aluminum liquid;

[0029] S4.2. Set the purge time to 1-3 minutes until no aluminum oxide film is formed on the surface of the aluminum liquid.

[0030] Preferably, the implementation steps of the step S5 of smelting and extracting aluminum from cold aluminum slag blocks are:

[0031] S5.1. Add the cold aluminum slag after pressing into the smelting furnace, set the smelting temperature to 650-800 ° C, and select potassium chloride or sodium chloride as the salt separation agent according to the composition of the aluminum slag;

[0032] S5.2. Keep the temperature in the smelting furnace stable and set the smelting time to 1-4h until the aluminum is completely melted and the salt separator reacts with the impurities.

[0033] Preferably, the implementation steps of water cooling and dissociation of hot salt slag in step S6 are:

[0034] S6.1. Use a water cooling device to cool the hot salt slag. The water cooling time is set to 3-8 minutes. The water flow rate is adjusted according to the amount of salt slag to ensure uniform cooling. After water cooling, the temperature of the salt slag is controlled at 100-150℃;

[0035] S6.2. Send the water-cooled salt slag into the disintegrator for disintegration. The disintegration time is adjusted to 2-5 minutes according to the hardness of the salt slag.

[0036] Preferably, the implementation steps of the cold ash vibration screening and grinding in step S7 are:

[0037] S7.1. Use a vibrating screener to vibrate and screen the cold ash. The screen aperture is selected according to the target particle size and the vibration frequency is set to 15-25 Hz.

[0038] S7.2. The screened material is sent to a ball mill for grinding. Steel balls or ceramic balls are selected as grinding media. The grinding time is adjusted to 1-4 hours according to the target particle size. The rotation speed of the grinder and the filling rate of the grinding media are controlled to ensure the grinding effect.

[0039] Preferably, the implementation steps of the step S8 of grading and screening the material after grinding are as follows:

[0040] S8.1. Use a grading screen to grade and screen the ground material, and select the screen and vibration frequency according to the particle size and density characteristics of the material;

[0041] S8.2. Control the speed at which the material passes through the screening machine to ensure that metallic aluminum and secondary aluminum ash fines are fully separated.

[0042] Preferably, the implementation steps of step S9 of collecting and comprehensively utilizing the metal aluminum are as follows:

[0043] S9.1. Collect the separated aluminum metal in a clean collection container to prevent aluminum metal contamination;

[0044] S9.2. Determine whether aluminum is used for smelting or as a raw material for other aluminum products based on market demand and the purity of aluminum metal;

[0045] S9.3. Different utilization plans should be formulated for aluminum metals of different purities and particle sizes to achieve comprehensive utilization in multiple ways.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The present invention relies on physical means for separation and recovery, does not generate harmful waste liquid and waste gas, and is environmentally friendly. Compared with pyrometallurgy, physical separation methods usually have lower energy consumption, which helps to reduce production costs. At the same time, the method of the present invention is relatively simple to operate and easy to realize industrial production. Through fine crushing, screening, magnetic separation, pressing, and smelting steps, valuable metals in aluminum ash slag are efficiently recovered, not only aluminum metal is recovered, but also by-products such as secondary aluminum ash fine powder are comprehensively utilized, thereby improving resource utilization. Therefore, the present invention's method for recovering valuable metals from recycled aluminum ash slag based on physical separation is an environmentally friendly, efficient, and economical recovery method, which is of great significance for promoting the recycling of aluminum resources, reducing environmental pollution, and improving economic benefits. DETAILED DESCRIPTION

[0048] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Example 1

[0050] The present invention proposes a method for recovering valuable metals from aluminum ash slag based on physical separation, comprising the following steps:

[0051] S1. Use a crusher to preliminarily crush the aluminum ash slag to make it uniform in particle size for subsequent processing, and use a screening machine to classify the crushed aluminum ash slag according to different particle sizes to remove oversized or undersized particles;

[0052] It should be further explained that the implementation steps of the preliminary crushing and screening of aluminum ash slag in step S1 are as follows:

[0053] S1.1. Perform preliminary crushing by using a jaw crusher or hammer crusher at an operating temperature of 15-30°C and adjusting the crushing ratio to 2-4 according to the hardness and particle size of the aluminum ash;

[0054] S1.2. Use a vibrating screen to screen and grade the crushed aluminum ash slag. Select a screen aperture of 5-10 mm according to the target particle size and set the vibration frequency to 15-25 Hz to ensure uniform grading of the material;

[0055] S2. Using a magnetic separator to magnetically separate the sieved aluminum ash to separate the ferromagnetic substances, including iron filings;

[0056] It should be further explained that the implementation steps of magnetic separation of ferromagnetic materials in step S2 are as follows:

[0057] S2.1. Under normal temperature operating environment, the screened aluminum ash slag is sent to the magnetic separator, and the magnetic field strength is adjusted to 0.5-1.5T according to the content of ferromagnetic substances;

[0058] S2.2. Control the speed of the material passing through the magnetic separator to 0.5-1.5m / s to ensure that the ferromagnetic material is fully separated;

[0059] S3. The hot aluminum ash slag is added to the hot aluminum ash press and a pressing aid including metallic silicon powder, silicon ash and potassium chloride is added, and the molten aluminum is squeezed out by applying static or dynamic pressure;

[0060] It should be further explained that the implementation steps of step S3 of extracting molten aluminum by squeezing hot aluminum ash slag are as follows:

[0061] S3.1. Adding hot aluminum ash slag into a hot aluminum ash press at an operating temperature of 600-800°C;

[0062] S3.2. According to the composition of aluminum ash, add 1-5% of metallic silicon powder, silicon ash, and potassium chloride as a pressing aid;

[0063] S3.3. Apply static or dynamic pressure of 5-20 MPa, and the pressing time is adjusted to 2-10 min according to the outflow of molten aluminum;

[0064] S4. Purging the aluminum liquid obtained by pressing with argon gas to protect the aluminum liquid surface from the formation of an aluminum oxide film, reduce its fluidity, and reduce the gas content in the aluminum liquid;

[0065] It should be further explained that the implementation steps of the argon gas purging of the aluminum liquid in step S4 are as follows:

[0066] S4.1. Use an argon purge device to evenly purge argon on the surface of the aluminum liquid. The argon flow rate is adjusted to 1-5L / min according to the surface area of ​​the aluminum liquid;

[0067] S4.2. The purge time is set to 1-3 minutes, until no aluminum oxide film is formed on the surface of the aluminum liquid;

[0068] S5. Add the cold aluminum slag after pressing into the smelting furnace, cover it with a salt separator for smelting and aluminum extraction, the salt separator is one of potassium chloride or sodium chloride, and the smelting temperature is 650°C-800°C to maximize aluminum melting and prevent oxidation;

[0069] It should be further explained that the implementation steps of step S5 of smelting and extracting aluminum from cold aluminum slag blocks are as follows:

[0070] S5.1. Add the cold aluminum slag after pressing into the smelting furnace, set the smelting temperature to 650-800 ° C, and select potassium chloride or sodium chloride as the salt separation agent according to the composition of the aluminum slag;

[0071] S5.2. Keep the temperature in the smelting furnace stable and set the smelting time to 1-4 hours until the aluminum is completely melted and the salt separation agent reacts with the impurities;

[0072] S6. The hot salt slag obtained by smelting is water-cooled for 3-8 minutes. The temperature of the salt slag after water cooling is controlled at 100-150°C. The water-cooled salt slag is dissociated using a dissociator to obtain cold ash slag;

[0073] It should be further explained that the implementation steps of water cooling and dissociation of hot salt slag in step S6 are as follows:

[0074] S6.1. Use a water cooling device to cool the hot salt slag. The water cooling time is set to 3-8 minutes. The water flow rate is adjusted according to the amount of salt slag to ensure uniform cooling. After water cooling, the temperature of the salt slag is controlled at 100-150℃;

[0075] S6.2. The water-cooled salt slag is sent to the dissociation machine for dissociation. The dissociation time is adjusted to 2-5 minutes according to the hardness of the salt slag;

[0076] S7. The cold ash is vibrated and screened to obtain materials of different particle sizes, and the screened materials are sent to a ball mill for grinding to deform the metallic aluminum and refine the inorganic alumina;

[0077] It should be further explained that the implementation steps of the cold ash vibration screening and grinding in step S7 are as follows:

[0078] S7.1. Use a vibrating screener to vibrate and screen the cold ash. The screen aperture is selected according to the target particle size and the vibration frequency is set to 15-25 Hz.

[0079] S7.2. The sieved material is sent to a ball mill for grinding. The grinding medium is steel balls or ceramic balls. The grinding time is adjusted to 1-4 hours according to the target particle size. The speed of the grinder and the filling rate of the grinding medium are controlled to ensure the grinding effect.

[0080] S8. After grinding, the material is graded and screened according to its particle size and density characteristics to separate metallic aluminum and secondary aluminum ash fine powder;

[0081] It should be further explained that the implementation steps of the material classification and screening after grinding in step S8 are as follows:

[0082] S8.1. Use a grading screen to grade and screen the ground material, and select the screen and vibration frequency according to the particle size and density characteristics of the material;

[0083] S8.2. Control the speed of the material passing through the screening machine to ensure that the metallic aluminum and the secondary aluminum ash fine powder are fully separated;

[0084] S9. Collect the separated aluminum metal for smelting or as raw material for other aluminum products, so as to achieve comprehensive utilization in multiple ways;

[0085] It should be further explained that the implementation steps of step S9 of collecting and comprehensively utilizing metal aluminum are as follows:

[0086] S9.1. Collect the separated aluminum metal in a clean collection container to prevent aluminum metal contamination;

[0087] S9.2. Determine whether aluminum is used for smelting or as a raw material for other aluminum products based on market demand and the purity of aluminum metal;

[0088] S9.3. Different utilization plans should be formulated for aluminum metals of different purities and particle sizes to achieve comprehensive utilization in multiple ways.

[0089] Example 2

[0090] In actual application, the above-mentioned method for recovering valuable metals from aluminum ash slag based on physical separation is specifically carried out in the following steps:

[0091] 1. Preliminary crushing and screening of aluminum ash

[0092] (1) Initial crushing:

[0093] Under the operating environment of 30℃, use a jaw crusher or a hammer crusher to initially crush the aluminum ash slag. According to the hardness and particle size of the aluminum ash slag, adjust the settings of the crusher to make the crushing ratio reach 4 to ensure that the particle size of the crushed aluminum ash slag is uniform and convenient for subsequent processing. During the operation, it is necessary to regularly check the wear of the crusher and replace the worn parts in time to ensure the crushing effect;

[0094] (2) Screening and grading:

[0095] Use a vibrating screening machine to screen and grade the crushed aluminum ash slag. According to the target particle size, select a 10mm screen aperture and set the vibration frequency to 25Hz to ensure uniform grading of the material. During the screening process, it is necessary to regularly check the blockage of the screen and clean the screen in time to ensure screening efficiency;

[0096] 2. Magnetic separation of ferromagnetic materials:

[0097] Under normal temperature operating environment, the screened aluminum ash slag is sent to the magnetic separator. According to the content of ferromagnetic substances, the magnetic field strength is adjusted to 1.5T, and the speed of the material passing through the magnetic separator is controlled to ensure that the ferromagnetic substances are fully separated;

[0098] 3. Extract molten aluminum from hot aluminum ash by pressing

[0099] (1) Add hot aluminum ash to the press:

[0100] At an operating temperature of 800°C, hot aluminum ash slag is quickly added to the hot aluminum ash press. In order to maintain the operating temperature, the press needs to be equipped with a heating device to ensure that the aluminum ash slag remains in a molten state during the pressing process;

[0101] (2) Adding pressing aid:

[0102] According to the composition of aluminum ash slag, add metal silicon powder, silicon ash, potassium chloride and other pressing aids at a ratio of 5%. The function of pressing aids is to improve the fluidity of molten aluminum and promote the separation of aluminum and impurities. Before adding the additives, it is necessary to fully stir and mix to ensure that the additives are evenly distributed in the aluminum ash slag;

[0103] (3) Apply pressure to squeeze:

[0104] Apply 20MPa static or dynamic pressure, and adjust the pressing time for 10min according to the outflow of molten aluminum. During the pressing process, the outflow of molten aluminum needs to be closely observed, and the pressure and time need to be adjusted in time to ensure the pressing effect. After the pressing is completed, the residue in the press should be cleaned in time to prepare for the next pressing;

[0105] 4. Argon purge of aluminum liquid:

[0106] Use an argon purge device to evenly purge argon on the surface of the aluminum liquid. The argon flow rate is adjusted according to the surface area of ​​the aluminum liquid. The purge time is set to 3 minutes until no aluminum oxide film is formed on the surface of the aluminum liquid. During the purge process, the purity of the argon must be ensured to avoid introducing impurities that affect the quality of the aluminum liquid.

[0107] 5. Cold aluminum slag smelting and aluminum extraction:

[0108] The cold aluminum slag after pressing is added into the smelting furnace, the smelting temperature is set to 800°C, potassium chloride or sodium chloride is selected as the salt separation agent according to the composition of the aluminum slag, and added into the furnace, the temperature in the smelting furnace is kept stable, and the smelting time is set to 4 hours, until the aluminum is completely melted and the salt separation agent reacts with the impurities;

[0109] 6. Water cooling and dissociation of hot salt slag:

[0110] Use a water cooling device to cool the hot salt slag. The water cooling time is set to 8 minutes. The water flow rate is adjusted according to the amount of salt slag to ensure uniform cooling. After water cooling, the temperature of the salt slag is controlled at 150°C. The water-cooled salt slag is sent to the dissociation machine for dissociation. The dissociation time is adjusted to 5 minutes according to the hardness of the salt slag.

[0111] 7. Vibration screening and grinding of cold ash:

[0112] Use a vibrating screener to vibrate and screen the cold ash. The screen aperture is selected according to the target particle size. The screened material is sent to a ball mill for grinding. Steel balls or ceramic balls are selected as grinding media. The grinding time is adjusted to 4 hours according to the target particle size. The speed of the grinder and the filling rate of the grinding media are controlled to ensure the grinding effect.

[0113] 8. Grading and screening of materials after grinding:

[0114] Use a grading screen to grade and screen the ground material. Select the screen and vibration frequency according to the particle size and density characteristics of the material, and control the speed of the material passing through the screen to ensure that the metallic aluminum and secondary aluminum ash fine powder are fully separated;

[0115] 9. Collection and comprehensive utilization of aluminum metal:

[0116] (1) Metal aluminum collection:

[0117] Use a clean collection container to collect the separated aluminum. During the collection process, ensure that the container is free of impurities and moisture to prevent aluminum contamination. The collected aluminum must be weighed, recorded, and stored in a designated location in a timely manner.

[0118] (2) Determine the use of aluminum metal:

[0119] According to the market demand and the purity of aluminum metal, determine whether it is used for smelting or as a raw material for other aluminum products. For high-purity aluminum metal, it can be used for smelting first; for aluminum metal with slightly lower purity, it can be considered as a raw material for aluminum products;

[0120] (3) Formulate a multi-channel comprehensive utilization plan:

[0121] Different utilization plans are formulated for aluminum metals of different purity and particle sizes;

[0122] like:

[0123] High-purity aluminum metal can be used to produce high-end aluminum products;

[0124] Low-purity aluminum metal can be used to produce ordinary aluminum products or as an alloy additive;

[0125] Secondary aluminum ash fine powder can be used to produce building materials or as raw materials for other industries;

[0126] Through comprehensive utilization in multiple ways, the utilization rate of metal aluminum can be improved, production costs can be reduced, and maximum utilization of resources can be achieved.

[0127] Through the above steps, the present invention relies on physical means for separation and recovery, does not generate harmful waste liquid and waste gas, is environmentally friendly, and compared with pyrometallurgy, physical separation methods usually have lower energy consumption, which helps to reduce production costs. At the same time, the method of the present invention is relatively simple to operate and easy to implement industrial production. Through fine crushing, screening, magnetic separation, pressing, and smelting steps, valuable metals in aluminum ash slag are efficiently recovered, not only aluminum metal is recovered, but also by-products such as secondary aluminum ash fine powder are comprehensively utilized, thereby improving resource utilization;

[0128] In summary, the method of recovering valuable metals from recycled aluminum ash based on physical separation is an environmentally friendly, efficient and economical recycling method, which is of great significance for promoting the recycling of aluminum resources, reducing environmental pollution and improving economic benefits.

[0129] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0130] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for recovering valuable metals from aluminum ash slag based on physical separation, characterized in that: The following steps are involved: S1. Use a crusher to preliminarily crush the aluminum ash slag to make it uniform in particle size, and use a screening machine to classify the crushed aluminum ash slag according to different particle sizes to remove oversized or undersized particles; S2. Using a magnetic separator to magnetically separate the sieved aluminum ash to separate the ferromagnetic material; S3. The hot aluminum ash slag is added to the hot aluminum ash press and a pressing aid including metallic silicon powder, silicon ash and potassium chloride is added, and the molten aluminum is squeezed out by applying static or dynamic pressure; S4. Purging the aluminum liquid obtained by pressing with argon gas to protect the aluminum liquid surface from the formation of an aluminum oxide film, reduce its fluidity, and reduce the gas content in the aluminum liquid; S5. Add the cold aluminum slag after pressing into the smelting furnace, cover it with a salt separator for smelting and aluminum extraction, the salt separator is one of potassium chloride or sodium chloride, and the smelting temperature is 650°C-800°C to maximize aluminum melting and prevent oxidation; S6. The hot salt slag obtained by smelting is water-cooled for 3-8 minutes. The temperature of the salt slag after water cooling is controlled at 100-150°C. The water-cooled salt slag is dissociated using a dissociator to obtain cold ash slag; S7. The cold ash is vibrated and screened to obtain materials of different particle sizes, and the screened materials are sent to a ball mill for grinding to deform the metallic aluminum and refine the inorganic alumina; S8. After grinding, the material is graded and screened according to its particle size and density characteristics to separate metallic aluminum and secondary aluminum ash fine powder; S9. Collect the separated aluminum metal and use it for smelting or as raw material for other aluminum products, so as to achieve comprehensive utilization in multiple ways.

2. The method for recovering valuable metals from aluminum ash slag based on physical separation according to claim 1, characterized in that: The implementation steps of the preliminary crushing and screening of aluminum ash slag in step S1 are as follows: S1.

1. Perform preliminary crushing by using a jaw crusher or hammer crusher at an operating temperature of 15-30°C and adjusting the crushing ratio to 2-4 according to the hardness and particle size of the aluminum ash; S1.

2. Use a vibrating screen to screen and grade the crushed aluminum ash slag. Select a screen aperture of 5-10mm according to the target particle size and set the vibration frequency to 15-25Hz to ensure uniform grading of the material.

3. A method for recovering valuable metals from aluminum ash slag based on physical separation according to claim 2, characterized in that: The implementation steps of the step S2 magnetic separation of ferromagnetic materials are as follows: S2.

1. Under normal temperature operating environment, the screened aluminum ash slag is sent to the magnetic separator, and the magnetic field strength is adjusted to 0.5-1.5T according to the content of ferromagnetic substances; S2.

2. Control the speed of materials passing through the magnetic separator to 0.5-1.5m / s to ensure that ferromagnetic materials are fully separated.

4. A method for recovering valuable metals from aluminum ash slag based on physical separation according to claim 3, characterized in that: The implementation steps of step S3 of extracting molten aluminum by squeezing hot aluminum ash are as follows: S3.

1. Adding hot aluminum ash slag into a hot aluminum ash press at an operating temperature of 600-800°C; S3.

2. According to the composition of aluminum ash, add 1-5% of metallic silicon powder, silicon ash, and potassium chloride as a pressing aid; S3.

3. Apply static or dynamic pressure of 5-20MPa, and the pressing time is adjusted to 2-10min according to the outflow of molten aluminum.

5. A method for recovering valuable metals from aluminum ash slag based on physical separation according to claim 4, characterized in that: The implementation steps of step S4 of purging aluminum liquid with argon are as follows: S4.

1. Use an argon purge device to evenly purge argon on the surface of the aluminum liquid. The argon flow rate is adjusted to 1-5L / min according to the surface area of ​​the aluminum liquid; S4.

2. Set the purge time to 1-3 minutes until no aluminum oxide film is formed on the surface of the aluminum liquid.

6. A method for recovering valuable metals from aluminum ash slag based on physical separation according to claim 5, characterized in that: The implementation steps of step S5 of smelting and extracting aluminum from cold aluminum slag blocks are as follows: S5.

1. Add the cold aluminum slag after pressing into the smelting furnace, set the smelting temperature to 650-800 ° C, and select potassium chloride or sodium chloride as the salt separation agent according to the composition of the aluminum slag; S5.

2. Keep the temperature in the smelting furnace stable and set the smelting time to 1-4h until the aluminum is completely melted and the salt separator reacts with the impurities.

7. A method for recovering valuable metals from aluminum ash slag based on physical separation according to claim 6, characterized in that: The implementation steps of step S6 of water cooling and dissociation of hot salt slag are: S6.

1. Use a water cooling device to cool the hot salt slag. The water cooling time is set to 3-8 minutes. The water flow rate is adjusted according to the amount of salt slag to ensure uniform cooling. After water cooling, the temperature of the salt slag is controlled at 100-150℃; S6.

2. Send the water-cooled salt slag into the disintegrator for disintegration. The disintegration time is adjusted to 2-5 minutes according to the hardness of the salt slag.

8. A method for recovering valuable metals from aluminum ash slag based on physical separation according to claim 7, characterized in that: The implementation steps of the cold ash vibration screening and grinding in step S7 are as follows: S7.

1. Use a vibrating screener to vibrate and screen the cold ash. The screen aperture is selected according to the target particle size and the vibration frequency is set to 15-25 Hz. S7.

2. The screened material is sent to a ball mill for grinding. Steel balls or ceramic balls are selected as grinding media. The grinding time is adjusted to 1-4 hours according to the target particle size. The rotation speed of the grinder and the filling rate of the grinding media are controlled to ensure the grinding effect.

9. A method for recovering valuable metals from aluminum ash slag based on physical separation according to claim 8, characterized in that: The implementation steps of the step S8 of grading and screening the material after grinding are as follows: S8.

1. Use a grading screen to grade and screen the ground material, and select the screen and vibration frequency according to the particle size and density characteristics of the material; S8.

2. Control the speed at which the material passes through the screening machine to ensure that metallic aluminum and secondary aluminum ash fines are fully separated.

10. A method for recovering valuable metals from aluminum ash slag based on physical separation according to claim 9, characterized in that: The implementation steps of step S9 of collecting and comprehensively utilizing aluminum metal in multiple ways are as follows: S9.

1. Collect the separated aluminum metal in a clean collection container to prevent aluminum metal contamination; S9.

2. Determine whether aluminum is used for smelting or as a raw material for other aluminum products based on market demand and the purity of aluminum metal; S9.

3. Different utilization plans should be formulated for aluminum metals of different purities and particle sizes to achieve comprehensive utilization in multiple ways.