A waste aluminum alloy material regeneration molecular sieve, a preparation method thereof and application thereof

Abstract

The application discloses a kind of waste aluminum alloy material regeneration molecular sieve and its preparation method and application, belong to solid waste resource utilization technical field.The preparation method specifically includes the following steps: (1) waste aluminum alloy material is mechanically pretreated;(2) mild alkali solution method, subsection alkali dissolution-acid washing method or high-temperature alkali fusion-water immersion method is selected, and metal Al and Si in pretreated alloy are dissolved to filtrate;(3) according to the typical ratio requirement of target molecular sieve, by additional silicon source silicon dioxide, NaOH, deionized water is regulated, and the gel system that meets the synthesis ratio of target molecular sieve is prepared;(4) aging, crystallization, cooling to room temperature, filtration, washing and drying, to obtain molecular sieve raw powder.The application is prepared through the process route of "mechanical pretreatment-dissolution-adjustment ratio-hydrothermal synthesis", and finally prepares the molecular sieve product suitable for catalytic reaction, realizes the high-value utilization of waste aluminum alloy.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization technology, and more specifically to a recycled molecular sieve of waste aluminum alloy material, its preparation method and application. Background Technology

[0002] With the rapid development of the automotive industry, the number of scrapped vehicles is also showing a rapid growth trend. In the weight distribution of a complete vehicle, the chassis system accounts for the second largest share after the body, approximately 23.8% of the total vehicle weight. Key components in the chassis system, such as wheel hubs, subframes, engine blocks and cylinder heads, steering knuckles, clutch housings, and transmission housings, are largely made of aluminum alloys. Specifically, engine blocks, cylinder heads, clutch housings, and transmission housings primarily use AC2A aluminum alloys; wheel hubs, pistons, and intake manifolds primarily use A356 and A357 aluminum alloys; and other parts mainly use A380, ADC12, ADC10, and AC8A aluminum alloys. Therefore, scrapped vehicles contain abundant waste aluminum alloy resources, and their efficient recycling is of significant strategic importance for alleviating aluminum resource supply pressure and promoting the development of a circular economy.

[0003] Currently, the recycling of waste aluminum alloys mainly focuses on the production of recycled aluminum alloys. Compared with producing the same amount of primary aluminum, the energy consumption of recycled aluminum is only 3% to 5%, showing significant advantages in energy conservation and emission reduction. However, existing waste aluminum alloy smelting and recycling technologies still have many prominent problems in practical applications. For example, during repeated smelting and recycling, material properties deteriorate due to impurity accumulation. In addition, there are problems such as serious secondary pollution and limited product added value. Therefore, there is an urgent need to develop more efficient, green, and high-value-added technologies for the utilization of waste aluminum alloys.

[0004] Waste aluminum alloys are not single-component aluminum materials, but complex systems containing multiple metallic elements. Besides the aluminum matrix, they commonly contain the main alloying element Si, strengthening elements Cu, Mg, Ni, and Zn, and impurity elements Fe, Cr, and Pb. From a catalytic materials perspective, Al and Si have significant conversion value and can be used to prepare silicon-aluminum molecular sieve supports. However, traditional recycling processes struggle to completely separate these alloying strengthening elements and impurity metals from the system, typically only allowing for dilution and control through the addition of pure aluminum ingots or intermediate alloys. With increasing regeneration cycles, impurities accumulate, ultimately leading to material performance degradation and limiting the alloy's reusability. Designing a leaching strategy based on alloy characteristics can not only selectively leach Si and Al from the alloy and convert them into molecular sieves, but also further recover impurity metals from the leaching residue, thus achieving a low-cost, green, and high-value-added resource recovery path.

[0005] However, there are currently no publicly reported technical solutions for directly converting waste aluminum alloys from automobiles into high-value molecular sieves. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a recycled molecular sieve for waste aluminum alloy materials, its preparation method and application, which selectively dissolves silicon and aluminum elements in waste aluminum alloys from automobiles and converts them into high-value molecular sieves, so as to solve the problems of impurity element recycling and enrichment, serious secondary pollution and low product added value in the existing waste aluminum alloy recycling and treatment technology.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for preparing recycled molecular sieves from waste aluminum alloy materials specifically includes the following steps: (1) Mechanically pretreat the waste aluminum alloy material to obtain a pretreated alloy; (2) Select a mild alkaline dissolution method, a segmented alkaline dissolution-acid washing method, or a high-temperature alkaline fusion-water immersion method to dissolve the metallic Al and Si in the pretreated alloy into the filtrate: (3) According to the typical ratio requirements of the target molecular sieve, the gel system that meets the synthesis ratio of the target molecular sieve is prepared by adding silicon dioxide, NaOH and deionized water to regulate the ratio. The target molecular sieve is an X-type molecular sieve, a Y-type molecular sieve, or a MOR-type molecular sieve; The typical ratio of X-type molecular sieves is Al2O3:SiO2:Na2O:H2O = 1:2~3:2~3:50~150; the typical ratio of Y-type molecular sieves is Al2O3:SiO2:Na2O:H2O = 1:3.5~6:2~5:100~200; and the typical ratio of MOR-type molecular sieves is Al2O3:SiO2:Na2O:H2O = 1:12~30:2~6:180~300. (4) The gel was aged, crystallized, cooled to room temperature, filtered, washed and dried in sequence to obtain molecular sieve powder.

[0009] Furthermore, in step (1) above, the waste aluminum alloy material is waste aluminum alloy parts from automobiles; mechanical pretreatment includes dismantling and sorting, crushing to a particle size of 2~6nm, magnetic separation to remove iron, eddy current separation to enrich aluminum alloy, and degreasing treatment.

[0010] Furthermore, in step (2) above, the specific operation of the mild alkaline dissolution method is as follows: the pretreated alloy is mixed with a NaOH solution with a concentration of 1~3 mol / L at a solid-liquid ratio of 1:5~1:10, and stirred at 60~90℃ for 1~4h. During the reaction, Al and Si in the aluminum alloy react with NaOH to generate soluble sodium aluminate (NaAlO2) and sodium silicate (Na2SiO3). The impurity elements in the alloy are relatively few and exist in the form of precipitates. After the reaction is completed, the mixture is filtered, the filtrate is collected, and a mixed solution of sodium aluminate and sodium silicate is obtained.

[0011] The further beneficial effect of the above method is that the mild alkali dissolution method is suitable for aluminum alloys such as A356, A357, and AC2A, with fewer impurities. No special treatment is required to remove impurities, and no strong alkali or high temperature conditions are needed to destroy the complex phase structure.

[0012] Furthermore, in step (2) above, the specific operation of the segmented alkali dissolution-acid washing method is as follows: The pretreated alloy is mixed with a NaOH solution with a concentration of 2~4 mol / L at a solid-liquid ratio of 1:8~1:12, and stirred at 80~100℃ for 3~6 hours. During the reaction, Al and Si are fully dissolved, Fe precipitates as Fe(OH)3, and Cu dissolves in excess concentrated NaOH solution to form soluble sodium tetrahydroxycubic acidate, which exists in the filtrate. After the reaction is completed, the mixture is filtered, the filtrate is collected, and 1.2 times the theoretical amount of Na2S·9H2O is added to the filtrate to remove the residual Cu. 2+ Complete precipitation in the form of CuS is achieved while avoiding the precipitation of Al in the form of Al(OH)3; after filtration again, a mixed solution of sodium aluminate and sodium silicate is obtained.

[0013] The further beneficial effect of the above-mentioned method is that the segmented alkaline dissolution-acid pickling method is suitable for aluminum alloys with high Cu content, such as ADC10, ADC12, and A380. When the Cu content is high, it is difficult to completely remove it by single-segment alkaline dissolution. Segmented treatment can ensure the complete removal of Cu.

[0014] Furthermore, in step (2) above, the specific operation of the high-temperature alkali fusion-water immersion method is as follows: the pretreated alloy and solid NaOH are mixed at a mass ratio of 1:1.5 to 1:2.5 and placed in a crucible. The mixture is then melted and reacted at 400 to 500°C for 1 to 2 hours. Under the conditions of high-temperature alkali fusion, Al and Si in the alloy react fully with NaOH to generate sodium silicate and sodium aluminate, while elements such as Ni, Mg, and Cu form insoluble oxides or hydroxides. After the melt product is cooled, it is leached with hot water, filtered to remove insoluble residues, and the filtrate is collected to obtain aluminosilicate solution.

[0015] The further beneficial effect of the above-mentioned method is that the high-temperature alkaline fusion-water immersion method is suitable for aluminum alloys with high Si content, such as AC8A aluminum alloy. Some of the silicon exists in the form of primary silicon particles, which naturally oxidize in the air to form a dense SiO2 passivation layer with a thickness of 1~10nm. This passivation layer has high chemical stability and reacts very slowly in NaOH solution at room temperature, resulting in a low silicon dissolution rate.

[0016] Furthermore, in step (4) above, the target molecular sieve is an X-type molecular sieve. The specific operation steps are as follows: the gel is aged at 20~30℃ for 12~24h to allow the silicon-aluminum species to fully polymerize and form crystal nucleus precursors; then the gel is transferred to a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 80~100℃ for 6~12h without adding seed crystals or organic template agents; after crystallization, it is cooled to room temperature, filtered, washed until neutral, and dried at 60~80℃ to obtain molecular sieve raw powder.

[0017] Furthermore, in step (4) above, the target molecular sieve is a Y-type molecular sieve. The specific operation steps are as follows: the gel is aged at 20~40℃ for 18~30h, and 2~5% of NaY seed crystals are added to allow the silicon-aluminum species to fully polymerize and form a crystal nucleus precursor; then the gel is transferred to a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 90~110℃ for 10~24h without adding organic template agents or calcination; after crystallization, it is cooled to room temperature, filtered, washed until neutral, and dried at 60~80℃ to obtain molecular sieve powder.

[0018] Furthermore, in step (4) above, the target molecular sieve is a MOR type molecular sieve. The specific operation steps are as follows: the gel is aged at 20~50℃ for 24~48h, 1%~5% of MOR type molecular sieve seed crystals and TEAOH template agent are added to allow the silicon-aluminum species to fully polymerize and form crystal nucleus precursors; then the gel is transferred to a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 150~180℃ for 24~72h; after crystallization, it is cooled to room temperature, filtered, washed until neutral, dried at 100~120℃, and finally calcined at 550~600℃ for 3~6h to remove the TEAOH template agent and obtain molecular sieve raw powder.

[0019] This invention also claims protection for a recycled molecular sieve of waste aluminum alloy material prepared by the above-described preparation method.

[0020] This invention also claims the application of a recycled molecular sieve of waste aluminum alloy material prepared by the above-described method in the preparation of catalysts. This recycled molecular sieve of waste aluminum alloy material can be loaded with active metals such as Ni, Co, Cu, and Ce to prepare catalysts for various catalytic reactions.

[0021] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention targets automotive waste aluminum alloys, such as A356 aluminum alloy, A357 aluminum alloy, AC2A aluminum alloy, ADC10 aluminum alloy, ADC12 aluminum alloy, A380 aluminum alloy, and AC8A aluminum alloy. Based on the characteristics of each material, it adopts a process route of "mechanical pretreatment - leaching - adjusting ratio - hydrothermal synthesis" and specifically selects strategies such as mild alkali dissolution, segmented alkali dissolution-acid washing, and high-temperature alkali melting-water immersion to finally prepare molecular sieve products suitable for catalytic reactions, thus realizing the high-value utilization of waste aluminum alloys.

[0022] 2. This invention breaks through the traditional single model of recycling waste aluminum alloys, which mainly relies on smelting and regenerating aluminum. It transforms waste aluminum alloys into high-value molecular sieve materials, realizing the transformation of waste aluminum resources from "low-value recycling" to "high-value conversion", and providing a new path for the resource utilization of automotive waste.

[0023] 3. Based on the characteristics of different grades of waste aluminum alloys, this invention designs three leaching processes: mild alkali dissolution, segmented alkali dissolution-acid washing, and high-temperature alkali melting-water immersion. These processes ensure high recovery rates of silicon and aluminum while guaranteeing the complete removal of impurity metals, thereby achieving high-value utilization of waste aluminum alloys.

[0024] 4. This invention uses waste aluminum alloy to replace high-purity chemical raw materials, which reduces the preparation cost of molecular sieves. The leaching solution can be directly used for molecular sieve synthesis, simplifying the process flow. At the same time, it avoids energy consumption and secondary pollution in the process of remelting waste aluminum alloys, and realizes the green recycling of solid waste.

[0025] 5. This invention establishes a technical system for the "high-value utilization" of automotive waste aluminum alloys. Different alkaline dissolution methods are matched according to the characteristics of the alloys, and corresponding hydrothermal conditions are selected according to the target molecular sieve. This achieves precise matching between waste sources and products, and has good prospects for industrialization and significant economic and social benefits. Attached Figure Description

[0026] Figure 1 The image shows the XRD pattern of the X-type molecular sieve raw powder prepared in Example 1. Figure 2 This is a diagram showing the catalytic effect of Ni-loaded X-type molecular sieve powder prepared in Example 1 on the CO2 methanation reaction. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1 The preparation method of recycled molecular sieve (X-type molecular sieve powder) from waste aluminum alloy materials specifically includes the following steps: (1) Using waste automobile wheel hub A356 alloy as raw material, after dismantling and sorting, it is crushed to a particle size of 5nm by jaw crusher, embedded iron filings are removed by permanent magnet drum magnetic separation, aluminum alloy is enriched by eddy current separation, and then surface oil is removed by acetone ultrasonic cleaning for 30 minutes to obtain A356 pretreated alloy material. (2) The pretreated alloy powder and the NaOH solution with a concentration of 2 mol / L were mixed at a solid-liquid ratio of 1:8 and stirred at 70°C for 3 hours to allow Al and Si in the aluminum alloy to react with NaOH to generate soluble sodium aluminate and sodium silicate. The impurity elements in the alloy were present in the form of precipitates, which were removed by filtration to obtain a mixed solution of sodium aluminate and sodium silicate. (3) Based on the typical ratio of Al2O3:SiO2:Na2O:H2O = 1:2.5:2.5:100 for X-type molecular sieves, the mixed solution of sodium aluminate and sodium silicate was adjusted by adding silicon source silica sol, NaOH, and deionized water to prepare a gel system that conforms to the synthesis ratio of X-type molecular sieves. (4) The gel was aged at 25°C for 18 hours to allow the silicon-aluminum species to fully polymerize and form crystal nuclei precursors. Then the gel was transferred to a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 90°C for 9 hours without the addition of seed crystals and organic template agents. After crystallization, the gel was cooled to room temperature, filtered, washed until neutral, and dried at 70°C to obtain X-type molecular sieve raw powder.

[0029] Example 2 The preparation method of recycled molecular sieve (Y-type molecular sieve powder) from waste aluminum alloy materials specifically includes the following steps: (1) Using waste cylinder block ADC12 aluminum alloy as raw material, the pretreated alloy powder is obtained by dismantling, sorting, crushing to a particle size of 5mm, magnetic separation to remove iron, eddy current separation to enrich aluminum alloy and degreasing treatment. (2) The pretreated alloy powder was mixed with a 3 mol / L NaOH solution at a solid-liquid ratio of 1:10 and stirred at 90°C for 4.5 h to allow Al and Si to dissolve completely, Fe to precipitate as Fe(OH)3, and Cu to dissolve in excess concentrated NaOH solution to form soluble sodium tetrahydroxycubic acidate, which was present in the filtrate. After the reaction was completed, the mixture was filtered, and the filtrate was collected. Na2S·9H2O, which was 1.2 times the theoretical amount, was added to the filtrate to remove the residual Cu. 2+ The solution is completely precipitated in the form of CuS, while avoiding the precipitation of Al in the form of Al(OH)3. After filtration again, a mixed solution of sodium aluminate and sodium silicate is obtained. (3) Based on the typical ratio of Y-type molecular sieve Al2O3:SiO2:Na2O:H2O=1:5:3.5:150, the mixed solution of sodium aluminate and sodium silicate was adjusted by adding silicon source silica sol, NaOH and deionized water to prepare a gel system that conforms to the synthesis ratio of Y-type molecular sieve. (4) The gel was aged at 30°C for 24 hours, and 3.5% NaY seed crystals were added to allow the silicon-aluminum species to fully polymerize and form crystal nucleus precursors. The gel was then transferred to a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 100°C for 17 hours. After crystallization, the gel was cooled to room temperature, filtered, washed until neutral, and dried at 70°C to obtain Y-type molecular sieve raw powder.

[0030] Example 3 The preparation method of recycled molecular sieves (MOR type molecular sieve powder) from waste aluminum alloy materials specifically includes the following steps: (1) Using AC8A aluminum alloy as raw material, the pretreated alloy powder is obtained by disassembling, sorting, crushing to a particle size of 5mm, removing iron by magnetic separation, enriching aluminum alloy by eddy current separation and degreasing. The pretreated alloy powder was mixed with solid NaOH at a mass ratio of 1:2 and placed in a nickel crucible. The mixture was then melted at 450°C for 1.5 hours to allow Al and Si in the alloy to fully react with NaOH to form sodium silicate and sodium aluminate, while elements such as Ni, Mg, and Cu formed insoluble oxides or hydroxides. After the melt product was cooled, it was leached with hot water and filtered to remove the insoluble residue, thus obtaining an aluminosilicate solution. (3) Based on the typical ratio of MOR type molecular sieve Al2O3:SiO2:Na2O:H2O=1:21:4:240, the above filtrate was adjusted by adding silicon source silica sol, NaOH and deionized water to prepare a gel system that conforms to the synthesis ratio of MOR type molecular sieve. (4) The gel was aged at 35°C for 36 hours, and 3% of MOR-type molecular sieve seed crystals and TEAOH template agent were added to allow the silicon-aluminum species to fully polymerize and form crystal nucleus precursors. The gel was then transferred to a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 165°C for 48 hours. After crystallization, the gel was cooled to room temperature, filtered, washed until neutral, dried at 110°C, and finally calcined at 600°C for 4.5 hours to remove the template agent, thus obtaining MOR-type molecular sieve raw powder.

[0031] Performance testing 1. XRD characterization The X-type molecular sieve powder obtained in Example 1 was placed in a muffle furnace and calcined at 550°C for 2 hours to completely remove physically adsorbed water and residual organic impurities from the pores. The catalyst composition was then analyzed using X-ray diffraction (XRD). The results are as follows: Figure 1 As shown.

[0032] Depend on Figure 1 It can be seen that the XRD pattern of the X-type molecular sieve raw powder obtained in Example 1 includes 15.4°, 23.2°, 26.6° and 30.9°, which correspond to the (331), (533), (642) and (751) crystal planes, respectively, indicating that X-type molecular sieve raw powder was indeed prepared in Example 1.

[0033] 2. Catalytic test Dissolve 1.252 g of nickel nitrate hexahydrate in 250 mL of distilled water and stir at low speed. Then add 5 g of the X-type molecular sieve powder prepared in Example 1. Slowly add ammonium hydroxide solution to the system to raise the pH from neutral to about 9.6 and continue stirring for 24 h. Then wash the catalyst with about 1 L of distilled water, let it stand at room temperature overnight, and then dry it in an oven at 100 °C overnight. Then perform segmented calcination at 250 °C for 40 min to remove moisture and generate intermediate Ni3(NO3)2(OH)4. Then calcinate at 400 °C for 3 h to gradually decompose the intermediate into nickel oxide. Finally, cool to room temperature, compress into tablets and sieve. 0.2 g of the 40-60 mesh catalyst was reduced at 500 °C for 3 h under a 20% H2 / Ar atmosphere. Then, a 20% CO2 / H2 reaction gas was introduced into a fixed-bed quartz tube reactor at a flow rate of 100 ml / min for performance testing. The CO2 conversion rate and CH4 selectivity were calculated. The results are as follows: Figure 2 As shown.

[0034] Depend on Figure 2 It can be seen that the CO2 conversion rate reaches its maximum of 75.5% at a temperature of 375℃, and the methane selectivity is 98.8% at this temperature.

[0035] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing recycled molecular sieves from waste aluminum alloy materials, characterized in that, Specifically, the following steps are included: (1) Mechanically pretreat the waste aluminum alloy material to obtain a pretreated alloy; (2) Select a mild alkaline dissolution method, a segmented alkaline dissolution-acid washing method, or a high-temperature alkaline fusion-water immersion method to dissolve the metallic Al and Si in the pretreated alloy into the filtrate: (3) According to the typical ratio requirements of the target molecular sieve, the gel system that meets the synthesis ratio of the target molecular sieve is prepared by adding silicon dioxide, NaOH and deionized water to regulate the ratio. The target molecular sieve is an X-type molecular sieve, a Y-type molecular sieve, or a MOR-type molecular sieve; The typical ratio of the X-type molecular sieve is Al2O3:SiO2:Na2O:H2O = 1:2~3:2~3:50~150; the typical ratio of the Y-type molecular sieve is Al2O3:SiO2:Na2O:H2O = 1:3.5~6:2~5:100~200; and the typical ratio of the MOR-type molecular sieve is Al2O3:SiO2:Na2O:H2O = 1:12~30:2~6:180~300. (4) The gel was aged, crystallized, cooled to room temperature, filtered, washed and dried in sequence to obtain molecular sieve powder.

2. The method for preparing recycled molecular sieves from waste aluminum alloy materials according to claim 1, characterized in that, In step (1), the waste aluminum alloy material is waste aluminum alloy parts from automobiles; the mechanical pretreatment includes dismantling and sorting, crushing to a particle size of 2~6nm, magnetic separation to remove iron, eddy current separation to enrich aluminum alloy, and degreasing treatment.

3. The method for preparing recycled molecular sieves from waste aluminum alloy materials according to claim 1, characterized in that, In step (2), the specific operation of the mild alkaline dissolution method is as follows: the pretreated alloy is mixed with a NaOH solution with a concentration of 1~3 mol / L at a solid-liquid ratio of 1:5~1:10, and stirred at 60~90℃ for 1~4h; after the reaction is completed, the mixture is filtered, the filtrate is collected, and a mixed solution of sodium aluminate and sodium silicate is obtained.

4. The method for preparing recycled molecular sieves from waste aluminum alloy materials according to claim 1, characterized in that, In step (2), the specific operation of the segmented alkaline dissolution-acid washing method is as follows: the pretreated alloy is mixed with a NaOH solution with a concentration of 2~4 mol / L at a solid-liquid ratio of 1:8~1:12, and stirred at 80~100℃ for 3~6h; after the reaction is completed, the mixture is filtered, the filtrate is collected, 1.2 times the theoretical amount of Na2S·9H2O is added to the filtrate, and the mixture is filtered again to obtain a mixed solution of sodium aluminate and sodium silicate.

5. The method for preparing recycled molecular sieves from waste aluminum alloy materials according to claim 1, characterized in that, In step (2), the specific operation of the high-temperature alkali fusion-water immersion method is as follows: the pretreated alloy and solid NaOH are mixed at a mass ratio of 1:1.5 to 1:2.5, placed in a crucible, and melted at 400 to 500°C for 1 to 2 hours; after the melt product is cooled, it is leached with hot water, filtered, and the filtrate is collected to obtain an aluminosilicate solution.

6. The method for preparing a recycled molecular sieve from waste aluminum alloy material according to claim 1, characterized in that, In step (4), the target molecular sieve is an X-type molecular sieve. The specific operation steps are as follows: the gel is aged at 20~30℃ for 12~24h; then the gel is transferred to a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 80~100℃ for 6~12h; after crystallization, it is cooled to room temperature, filtered, washed until neutral, and dried at 60~80℃ to obtain molecular sieve raw powder.

7. The method for preparing recycled molecular sieves from waste aluminum alloy materials according to claim 1, characterized in that, In step (4), the target molecular sieve is a Y-type molecular sieve. The specific operation steps are as follows: the gel is aged at 20~40℃ for 18~30h, and 2~5% NaY seed crystals are added; then the gel is transferred to a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 90~110℃ for 10~24h; after crystallization, it is cooled to room temperature, filtered, washed until neutral, and dried at 60~80℃ to obtain molecular sieve powder.

8. The method for preparing a recycled molecular sieve from waste aluminum alloy material according to claim 1, characterized in that, In step (4), the target molecular sieve is a MOR type molecular sieve. The specific operation steps are as follows: the gel is aged at 20~50℃ for 24~48h, and 1%~5% of MOR type molecular sieve seed crystals and TEAOH template agent are added; then the gel is transferred to a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 150~180℃ for 24~72h; after crystallization, it is cooled to room temperature, filtered, washed until neutral, dried at 100~120℃, and finally calcined at 550~600℃ for 3~6h to remove the TEAOH template agent to obtain the molecular sieve raw powder.

9. A recycled molecular sieve of waste aluminum alloy material prepared by the preparation method according to any one of claims 1-8.

10. The application of a recycled molecular sieve of waste aluminum alloy material prepared by any one of claims 1-8 in the preparation of catalysts.

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