Novel molecular sieve special for electronic control air suspension of new energy automobile and preparation process of molecular sieve

Abstract

The invention relates to the technical field of molecular sieves, and particularly discloses a novel molecular sieve special for an electric control air suspension of a new energy automobile and a preparation process thereof. The raw material composition of the raw material nodules is limited, attapulgite, calcined coal gangue powder and porous silicon carbide nanosheets are added on the basis of molecular sieve raw powder, and an adhesive and a forming aid are preferably selected. Through cooperation of the components, the molecular sieve provided by the invention can simultaneously have an excellent adsorption effect and good strength performance, not only can efficiently remove moisture in an automobile electric control air suspension system, but also can bear back-and-forth purging of regenerated air, is not easy to generate a pulverization phenomenon, overcomes the defects of domestic molecular sieves, and has a wide application prospect. And the requirement of high-end development of new energy automobiles in the future can be fully met.

Description

Technical Field

[0001] The present application relates to the field of molecular sieve technology, and more specifically, to a novel molecular sieve specially used for electronically controlled air suspension of new energy vehicles and a preparation process thereof. Background Art

[0002] The automotive electronically controlled air suspension system is mainly composed of air springs, shock absorbers, guide mechanisms, air supply units and other modules, among which the air supply unit includes air compressors, molecular sieve drying tanks, gas storage tanks, gas distribution valves and other components. The working principle of the automotive electronically controlled air suspension system is that the air compressor compresses the outside air, removes impurities such as moisture through the molecular sieve drying tank, and the dry compressed air is transported to the gas storage tank for storage, and then distributed to each air spring as needed through the gas distribution valve to adjust the vehicle height and suspension stiffness. In the above system, the molecular sieve drying tank has two main functions. One is to remove moisture from the compressed air to prevent moisture from entering the air springs, gas storage tanks, control and other components, and avoid corrosion, rust and damage of components caused by moisture, thereby extending the service life of the system; the second is to ensure that the air entering the system is dry, so that components such as air springs can work stably under various environmental conditions, ensure that the performance of the suspension system is not affected by moisture, always maintain good elasticity and adjustment functions, and improve driving safety and comfort.

[0003] Molecular sieve is the core component of the molecular sieve drying tank of the electronically controlled air suspension of new energy vehicles. It has long been highly dependent on imports, and most of the products on the market are from Germany. Compared with imported products, domestic molecular sieve products have certain shortcomings in both dynamic water adsorption capacity and strength. When the air humidity is 50%, the temperature is 25°C, and the air flow rate is 1L / min, the dynamic water absorption capacity of various types of domestic molecular sieves (taking 3-5mm as an example) is usually around 10-15%. When the molecular sieve drying tank is saturated with adsorption, it needs to be regenerated. During regeneration, the system will change the pressure in the drying tank, reduce the pressure in the drying tank by controlling the valve, and use the expansion of compressed air to take away the moisture adsorbed by the molecular sieve, so that the molecular sieve can restore its adsorption capacity. Conventional 2.0-2.5mm molecular sieve products usually have a strength of about 30N, which is difficult to withstand the back and forth purge of regeneration air, and the molecular sieve is prone to powdering.

[0004] Regarding the above-mentioned related technologies, the inventors believe that the domestic molecular sieves currently on the market cannot meet the normal usage and life requirements due to their shortcomings such as low strength, poor water absorption capacity and short life, and are even unable to match the imported brands, making it difficult to fully meet the needs of the high-end development of new energy vehicles in the future. Summary of the invention

[0005] In the related art, domestic molecular sieves have low strength and poor water absorption capacity, so their lifespan is short and it is difficult to fully meet the needs of high-end development of new energy vehicles in the future. In order to improve this defect, the present application provides a new type of molecular sieve dedicated to electronically controlled air suspension of new energy vehicles and its preparation process.

[0006] In the first aspect, the present application provides a novel molecular sieve for electronically controlled air suspension of new energy vehicles, which adopts the following technical solution: A novel molecular sieve specially used for electronically controlled air suspension of new energy vehicles. The molecular sieve is formed by firing raw material balls. The raw material balls include the following components in parts by weight: 100-110 parts of molecular sieve raw powder, 20-25 parts of attapulgite, 3-5 parts of calcined coal gangue powder, 2.5-3.5 parts of porous silicon carbide nanosheets, 3-5 parts of pore formers, 30-35 parts of adhesives, 8-10 parts of peptizers, 2-3 parts of molding aids, and 15-18 parts of water. The adhesive includes pseudo-boehmite and sodium carboxymethyl cellulose, and the molding aid is sesbania powder.

[0007] By adopting the above technical scheme, the present application defines the raw material composition of the raw material ball, adds attapulgite, calcined coal gangue powder and porous silicon carbide nanosheets on the basis of the original molecular sieve powder, and also optimizes the adhesive and molding aid. Attapulgite is a natural clay mineral and a mesoporous material. After calcination, it will remove adsorbed water and crystallization water, and form some macropores through secondary pore formation, thus presenting a three-level pore structure of micropores-mesopores-macroporous together with the original molecular sieve powder; in addition, the water vapor generated during the secondary pore formation can also form channels when migrating, thereby increasing the connectivity between the pores; calcined coal gangue powder and porous silicon carbide nanosheets themselves have developed pores and high strength, which can play a good reinforcing role while optimizing the adsorption capacity of the molecular sieve; the pseudo-boehmite in the adhesive itself has a developed spatial network structure, which helps to improve the adsorption effect of the molecular sieve, and can work with sodium carboxymethyl cellulose and sesbania powder to enhance the bonding between the components; sodium carboxymethyl cellulose, pore-forming agent and sesbania powder can also form new pores while losing weight during calcination, giving the molecular sieve a more complex pore structure. Through the synergistic cooperation between the above components, the molecular sieve of the present application can simultaneously have excellent adsorption effect and good strength performance. It can not only efficiently remove moisture in the automotive electronic air suspension system, but also can withstand the back and forth blowing of regenerated air and is not prone to powdering. It overcomes the shortcomings of domestic molecular sieves and can fully meet the needs of high-end development of future new energy vehicles.

[0008] Preferably, the calcined coal gangue powder is prepared according to the following method: The gangue is crushed, the crushed product is ground and sieved to obtain gangue powder, the gangue powder and sodium carbonate are mixed and ground to obtain a mixture, the mixture is calcined, and the calcined product is then put into a sulfuric acid solution for oil bath heating, and then filtered, and the filter residue is washed and dried to obtain calcined gangue powder.

[0009] By adopting the above-mentioned technical scheme, the present application adopts the method of alkali hot melt + acid leaching to modify the coal gangue powder. The alkali hot melt treatment can produce sodium silicate and nepheline crystal phases in the coal gangue powder. After that, acid leaching can produce amorphous silica with a mesoporous structure, which can participate in the formation of the pore structure of the molecular sieve particles and help improve the adsorption performance of the molecular sieve particles.

[0010] Preferably, the calcination temperature of the mixture is 750-820°C.

[0011] By adopting the above technical solution, the present application optimizes the calcination temperature of the mixture, which helps to improve the adsorption performance of the molecular sieve particles.

[0012] Preferably, the weight ratio of the coal gangue to sodium carbonate is 1:(0.65-0.75).

[0013] By adopting the above technical solution, the present application optimizes the weight ratio of coal gangue to sodium carbonate, which helps to improve the adsorption performance of molecular sieve particles.

[0014] Preferably, the porous silicon carbide nanosheets are prepared according to the following method: (1) mixing graphite sheets, silicon monoxide, and silicon element with water to obtain a slurry, performing ultrasonic dispersion on the slurry, and then drying the slurry to obtain a precursor for later use; (2) calcining the precursor in an inert atmosphere, immersing the calcined product in a mixed acid solution of hydrofluoric acid and nitric acid, filtering the product after immersion, washing the filter residue, and then calcining the product in an air atmosphere to obtain a porous silicon carbide nanosheet.

[0015] By adopting the above technical solution, the present application uses graphite sheets as a substrate, reacts silicon monoxide and silicon with the graphite sheets under roasting conditions, partially converts the graphite sheets into silicon carbide, and then removes silicon by acid solution and removes carbon by roasting to obtain porous silicon carbide nanosheets with nanoscale pores.

[0016] Preferably, the graphite sheet is prepared according to the following method: Under the protection of an inert atmosphere, expandable graphite is added to an alumina crucible for heating and expansion to obtain expanded graphite, and the expanded graphite and polyoxyethylene ether are added to deionized water to obtain a graphite dispersion, which is sand-milled and then filtered, and the filter cake is washed and dried to obtain a graphite sheet.

[0017] By adopting the above technical solution, the present application first prepares expanded graphite by heating and expanding, and then dissociates the expanded graphite by means of polyoxyethylene ether and sand milling to obtain graphite sheets that can be used to prepare porous silicon carbide nanosheets.

[0018] Preferably, the graphite sheet has a D 50 The particle size is 40-70μm.

[0019] By adopting the above technical solution, the present application optimizes the D of the graphite sheet. 50 The particle size can make the porous silicon carbide nanosheets have more pores, which helps to improve the adsorption performance of the molecular sieve particles.

[0020] Preferably, the pore former comprises rice husk powder.

[0021] By adopting the above technical solution, the rice husk powder contains not only combustible components but also a large amount of silicon dioxide, so it can not only assist in pore formation, but also the remaining silicon dioxide after roasting can reinforce the molecular sieve particles, thereby improving the strength performance of the molecular sieve particles.

[0022] Preferably, the pseudo-boehmite is prepared according to the following method: The sodium aluminate solution and the aluminum sulfate solution are mixed, reacted at 60-70°C and pH=6.5-8.0, and after the reaction is completed, allowed to stand and age for 60-120 minutes, and then filtered. The filter cake is washed with deionized water, and then the filter cake is dried and crushed to obtain pseudo-boehmite.

[0023] By adopting the above technical solution, the present application optimizes the preparation conditions of pseudo-boehmite, which helps to improve the strength performance of molecular sieve particles.

[0024] In the second aspect, the present application provides a preparation process of a novel molecular sieve specially used for electronically controlled air suspension of new energy vehicles, which adopts the following technical solution.

[0025] A preparation process of a novel molecular sieve specially used for electronically controlled air suspension of new energy vehicles comprises the following steps: (1) mixing molecular sieve raw powder, attapulgite, calcined coal gangue powder, porous silicon carbide nanosheets, pore-forming agent, and molding aid to obtain material A, which is set aside; mixing a binder and water to obtain material B, which is set aside; (2) Add material A and material B into a granulator and mix them. After granulation, raw material balls are obtained. The raw material balls are dried and then roasted in a muffle furnace. After roasting, the temperature is lowered to obtain a molecular sieve specially used for electronically controlled air suspension of new energy vehicles.

[0026] By adopting the above technical solution, the present application first prepares material A and material B respectively, and then uses material A and material B to granulate to obtain raw material balls. After roasting, the raw material balls can be converted into molecular sieves specially used for electronically controlled air suspension of new energy vehicles.

[0027] In summary, this application has the following beneficial effects: 1. This application defines the raw material composition of the raw material ball, adds attapulgite, calcined coal gangue powder and porous silicon carbide nanosheets on the basis of the original molecular sieve powder, and also selects adhesives and molding aids. Through the synergistic cooperation between the above components, the molecular sieve of this application can have excellent adsorption effect and good strength performance at the same time, not only can it efficiently remove moisture in the automotive electronic air suspension system, but also can withstand the back and forth purge of regenerated air, and is not prone to powdering, overcoming the shortcomings of domestic molecular sieves, and can fully meet the needs of high-end development of new energy vehicles in the future.

[0028] 2. This application adopts the method of alkali hot melt + acid leaching to modify the coal gangue powder. The alkali hot melt treatment can produce sodium silicate and nepheline crystal phases in the coal gangue powder. After that, acid leaching can produce amorphous silicon dioxide with a mesoporous structure, which can participate in the formation of the pore structure of the molecular sieve particles and help improve the adsorption performance of the molecular sieve particles.

[0029] 3. The present application uses graphite sheets as a substrate, and reacts silicon monoxide and silicon with the graphite sheets under calcination conditions to partially convert the graphite sheets into silicon carbide, and then removes silicon with acid and carbon by calcination to obtain porous silicon carbide nanosheets with nanoscale pores. DETAILED DESCRIPTION

[0030] The present application is further described in detail below in conjunction with embodiments, preparation examples and comparative examples. The raw materials involved in the present application can all be obtained commercially.

[0031] Preparation example of calcined coal gangue powder The following is an explanation using Preparation Example 1.

[0032] Preparation Example 1 In this preparation example, calcined coal gangue powder was prepared according to the following method: The gangue is crushed, and the crushed product is ground and passed through a 200-mesh sieve to obtain gangue powder. The gangue powder and sodium carbonate are mixed in a weight ratio of 1:0.8 and ground to obtain a mixture. The mixture is calcined at 730°C for 5 hours, and then the calcined product is put into a 4 mol / L sulfuric acid solution, heated in an oil bath at 90°C for 5 hours, and then filtered. The filter residue is washed and dried to obtain calcined gangue powder.

[0033] Preparation Example 2 The difference between this preparation example and preparation example 1 is that the calcination temperature of the mixture is 750°C.

[0034] Preparation Example 3 The difference between this preparation example and preparation example 1 is that the calcination temperature of the mixture is 790°C.

[0035] Preparation Example 4 The difference between this preparation example and preparation example 1 is that the calcination temperature of the mixture is 820°C.

[0036] Preparation Example 5 The difference between this preparation example and preparation example 4 is that the mixture is made of coal gangue powder and sodium carbonate in a weight ratio of 1:0.75.

[0037] Preparation Example 6 The difference between this preparation example and preparation example 4 is that the mixture is made of coal gangue powder and sodium carbonate in a weight ratio of 1:0.70.

[0038] Preparation Example 7 The difference between this preparation example and preparation example 4 is that the mixture is made of coal gangue powder and sodium carbonate in a weight ratio of 1:0.65.

[0039] Preparation example of porous silicon carbide nanosheets The following is an explanation using Preparation Example 8.

[0040] Preparation Example 8 The graphite sheet used in this preparation example was prepared as follows: Under the protection of an inert atmosphere, expandable graphite was added to an alumina crucible, heated and expanded at 1000°C for 8 minutes to obtain expanded graphite, and the expanded graphite and polyoxyethylene ether were mixed in a weight ratio of 20:1 and added into deionized water to obtain a graphite dispersion containing 9.5 wt% of expanded graphite. The graphite dispersion was sand-milled and then filtered, and the filter cake was washed and dried to obtain D 50 Graphite flakes with a particle size of 20 μm.

[0041] This preparation example provides a porous silicon carbide nanosheet, which is prepared according to the following method: (1) Premixing graphite sheets, silicon monoxide and silicon element in a molar ratio of 2.5:1:1, and then adding water to mix to obtain a slurry with a solid content of 10 wt%, ultrasonically dispersing the slurry, and then drying to obtain a precursor, which is dried at 100°C for 24 hours for use; (2) In an inert atmosphere at 1350°C, the precursor is calcined for 2 hours. After cooling, the calcined product is immersed in a 10 wt% mixed acid solution of hydrofluoric acid and nitric acid in a molar ratio of HF:HNO3=3:1, and filtered after immersion for 12 hours. The filter residue is washed and then calcined at 650°C in an air atmosphere for 4 hours to obtain a porous silicon carbide nanosheet.

[0042] Preparation Example 9 The difference between this Preparation Example and Preparation Example 8 is that the D50 particle size of the graphite sheet is 40 μm.

[0043] Preparation Example 10 The difference between this Preparation Example and Preparation Example 8 is that the D50 particle size of the graphite sheet is 55 μm.

[0044] Preparation Example 11 The difference between this Preparation Example and Preparation Example 8 is that the D50 particle size of the graphite sheet is 70 μm.

[0045] Preparation Example of Pseudoboehmite The following is an explanation using Preparation Example 12 as an example.

[0046] Preparation Example 12 In this preparation example, pseudo-boehmite was prepared according to the following method: A sodium aluminate solution with an aluminum oxide mass concentration (converted according to the aluminum content) of 120 g / L and an aluminum sulfate solution with an aluminum oxide mass concentration (converted according to the aluminum content) of 85 g / L are mixed, and reacted at 50°C and pH=5.5. After the reaction is completed, the mixture is allowed to stand and age for 45 minutes, and then filtered. The filter cake is washed with deionized water until the mass fraction of sodium oxide in the filter cake is less than 0.05%, and then the filter cake is dried and crushed to obtain pseudo-boehmite.

[0047] Preparation Example 13 The difference between this preparation example and preparation example 12 is that the reaction temperature of the sodium aluminate solution and the aluminum sulfate solution is 60° C., the reaction pH is 6.5, and the aging time after the reaction is 60 min.

[0048] Preparation Example 14 The difference between this preparation example and preparation example 12 is that the reaction temperature of the sodium aluminate solution and the aluminum sulfate solution is 65° C., the reaction pH is 7.5, and the aging time after the reaction is 90 min.

[0049] Preparation Example 15 The difference between this preparation example and preparation example 12 is that the reaction temperature of the sodium aluminate solution and the aluminum sulfate solution is 70° C., the reaction pH is 8.0, and the aging time after the reaction is 120 min. Example

[0050] Examples 1-5 The following description is given by taking Example 1 as an example.

[0051] Example 1 In this embodiment, the original molecular sieve powder is 200 mesh 13X molecular sieve, the specification of attapulgite is 200 mesh, the calcined coal gangue powder is prepared according to the method of Preparation Example 1, the porous silicon carbide nanosheets are prepared according to the method of Preparation Example 8, the pore-forming agent is corn starch, the adhesive is a mixture of pseudo-boehmite and sodium carboxymethyl cellulose in a weight ratio of 3:2, the pseudo-boehmite is prepared according to the method of Preparation Example 12, the peptizing agent is nitric acid (65wt%), and the molding aid is sesbania powder (120 mesh).

[0052] The present embodiment provides a new type of molecular sieve specially used for electronically controlled air suspension of new energy vehicles. The molecular sieve is formed by firing raw balls. The raw balls include the following components in parts by weight: 100 g of molecular sieve powder, 20 g of attapulgite, 3 g of calcined coal gangue powder, 2.5 g of porous silicon carbide nanosheets, 3 g of pore-forming agent, 30 g of adhesive, 8 g of peptizing agent, 2 g of molding aid, and 15 g of water.

[0053] This embodiment provides a preparation process of a novel molecular sieve for electronically controlled air suspension of new energy vehicles, comprising the following steps: (1) mixing molecular sieve raw powder, attapulgite, calcined coal gangue powder, porous silicon carbide nanosheets, pore-forming agent, and molding aid to obtain material A, which is set aside; mixing a binder and water to obtain material B, which is set aside; (2) Add material A and material B into a granulator and mix them. After granulation, raw balls with an average particle size of 2.5 mm are obtained. The raw balls are dried at 110°C for 2 hours, and then calcined at 550°C in a muffle furnace for 2 hours. After calcination, the raw balls are cooled to obtain a molecular sieve specially used for electronically controlled air suspension of new energy vehicles.

[0054] As shown in Table 1, the differences between Examples 1-5 mainly lie in the different raw material ratios of the raw material balls.

[0055] Table 1 Raw material ratio of raw material ball sample Example 1 Example 2 Example 3 Example 4 Example 5 Molecular sieve powder / g 100 102 105 108 110 Attapulgite / g 20 21 22 24 25 Calcined coal gangue powder / g 3 3.5 4 4.5 5 Porous silicon carbide nanosheets / g 2.5 2.8 3.0 3.2 3.5 Pore ​​forming agent / g 3 3.5 4 4.5 5 Adhesive / g 30 32 33 34 35 Peptizer / g 8 8.5 9 9.5 10 Molding aid / g 2 2.2 2.5 2.8 3 Water / g 15 16 16 17 18 Example 5-11 As shown in Table 2, the difference between Examples 5-11 is that the preparation examples of calcined coal gangue powder are different.

[0056] Table 2 Preparation example of calcined coal gangue powder sample Preparation Example Example 5 Preparation Example 1 Example 6 Preparation Example 2 Example 7 Preparation Example 3 Example 8 Preparation Example 4 Example 9 Preparation Example 5 Example 10 Preparation Example 6 Embodiment 11 Preparation Example 7 Example 12 The difference between this embodiment and embodiment 11 is that the porous silicon carbide nanosheets are prepared according to the method of preparation example 9.

[0057] Example 13 The difference between this embodiment and embodiment 11 is that the porous silicon carbide nanosheets are prepared according to the method of preparation example 10.

[0058] Embodiment 14 The difference between this embodiment and embodiment 11 is that the porous silicon carbide nanosheets are prepared according to the method of preparation example 11.

[0059] Embodiment 15 The difference between this embodiment and embodiment 14 is that the pore-forming agent is 500-mesh rice husk powder.

[0060] Example 16 The difference between this embodiment and Example 15 is that the pseudo-boehmite is prepared according to the method of Preparation Example 13.

[0061] Embodiment 17 The difference between this embodiment and Example 15 is that the pseudo-boehmite is prepared according to the method of Preparation Example 14.

[0062] Embodiment 18 The difference between this embodiment and Example 15 is that the pseudo-boehmite is prepared according to the method of Preparation Example 15.

[0063] Comparative Example Comparative Example 1 This comparative example provides a molecular sieve particle, which is formed by sintering a raw material ball. The raw material ball includes the following components in parts by weight: 128.5 g of molecular sieve raw powder, 30 g of a binder, 8 g of a peptizing agent, 2 g of a molding aid, and 15 g of water.

[0064] This embodiment provides a preparation process of a novel molecular sieve for electronically controlled air suspension of new energy vehicles, comprising the following steps: (1) Mixing molecular sieve raw powder and molding aid to obtain material A, which is set aside; mixing binder and water to obtain material B, which is set aside; (2) Add material A and material B into a granulator and mix them. After granulation, raw balls with an average particle size of 2.5 mm are obtained. The raw balls are dried at 110°C for 2 hours, and then calcined at 550°C in a muffle furnace for 2 hours. After calcination, the raw balls are cooled to obtain a molecular sieve specially used for electronically controlled air suspension of new energy vehicles.

[0065] Comparative Example 2 The difference between this comparative example and Example 1 is that the attapulgite in the raw material formula of the raw material ball is replaced by the same weight of molecular sieve raw powder.

[0066] Comparative Example 3 The difference between this comparative example and Example 1 is that the porous silicon carbide nanosheets in the raw material formula of the raw material ball are replaced with the same weight of molecular sieve raw powder.

[0067] Comparative Example 4 The difference between this comparative example and Example 1 is that the pore former in the raw material formula of the raw material ball is replaced by the same weight of molecular sieve raw powder.

[0068] Comparative Example 5 The difference between this comparative example and Example 1 is that the pseudo-boehmite in the raw material formula of the raw material ball is replaced by the same weight of sodium carboxymethyl cellulose.

[0069] Performance testing methods 1. Referring to the record of "GB / T 6287-2021 Molecular Sieve Static Water Adsorption Determination Method", the molecular sieves (particles) of each embodiment and comparative example were tested for water absorption performance. After the static water adsorption amount was measured, the test result of Comparative Example 1 was used as a benchmark to calculate the ratio between the static water adsorption amount measured in each embodiment and comparative example and the static water adsorption amount measured in Comparative Example 1. The ratio was recorded as the relative water absorption rate. The results are shown in Table 3.

[0070] 2. The compressive strength of the molecular sieves (particles) of each embodiment and comparative example was tested using a LJ5000 compression testing machine (range 0-5000N). Then, based on the compressive strength of comparative example 1, the ratio between the compressive strength measured in each embodiment and comparative example and the compressive strength of comparative example 1 was calculated, and the ratio was recorded as the relative compressive strength. The results are shown in Table 3.

[0071] Table 3 Test results Combining Examples 1-5 and Comparative Example 1 and Table 3, it can be seen that the relative water absorption and relative compressive strength measured in Examples 1-5 are both high. This is because the present application defines the raw material composition of the raw material ball, adds attapulgite, calcined coal gangue powder and porous silicon carbide nanosheets on the basis of the original molecular sieve powder, and also selects adhesives and molding aids. Through the synergistic coordination between the above components, the molecular sieve of the present application can simultaneously have excellent adsorption effect and good strength performance, not only can it efficiently remove moisture in the automotive electronic air suspension system, but also can withstand the back and forth purge of regenerated air, and is not prone to pulverization, overcoming the shortcomings of domestic molecular sieves, and can fully meet the needs of high-end development of new energy vehicles in the future.

[0072] Combining Example 1 and Comparative Example 2 and Table 3, it can be seen that the relative water absorption rate measured in Comparative Example 2 is lower. This is because Comparative Example 2 lacks attapulgite, and cannot form macropores through secondary pore formation, making it difficult to form a tertiary pore structure of micropores-mesopores-macropores. It is also impossible to increase the connectivity between pores through the water vapor generated during the secondary pore formation, resulting in poor water absorption performance of the molecular sieve particles in Comparative Example 2.

[0073] Combining Example 1 and Comparative Example 3 and Table 3, it can be seen that the relative water absorption rate and relative compressive strength measured in Comparative Example 3 are both low. This is because Comparative Example 3 lacks porous silicon carbide nanosheets, and not only can the pores of the porous silicon carbide nanosheets not be used to improve the adsorption capacity, but also the high strength of silicon carbide cannot be used to achieve reinforcement.

[0074] Combining Example 1 and Comparative Example 4 with Table 3, it can be seen that the relative water absorption rate measured in Comparative Example 4 is lower. This is because Comparative Example 4 cannot promote the formation of pores through the decomposition of the pore-forming agent, resulting in poor water absorption effect of the molecular sieve particles.

[0075] Combining Example 1 and Comparative Example 5 and Table 3, it can be seen that the relative water absorption and relative compressive strength measured in Comparative Example 5 are both low. This is because Comparative Example 5 cannot optimize the pore distribution through the relatively developed spatial network structure of pseudo-boehmite itself, and sodium carboxymethyl cellulose alone cannot effectively achieve adhesion between the components.

[0076] It can be seen from Examples 5-11 and Table 3 that when the calcination temperature of the mixture is 750-820°C, or the weight ratio of gangue to sodium carbonate is 1:(0.65-0.75), the adsorption performance of the molecular sieve is better.

[0077] Combining Example 11, Examples 12-14 and Table 3, it can be seen that when the D of the graphite sheet 50 When the particle size is 40-70 μm, the prepared porous silicon carbide nanosheets have more pores, which helps to improve the adsorption performance of the molecular sieve particles.

[0078] Combining Example 14, Example 15 and Table 3, it can be seen that the relative compressive strength measured in Example 15 is higher. This is because the rice husk powder contains more silicon dioxide in addition to the combustible components. Therefore, it can not only assist in pore formation, but also the remaining silicon dioxide after roasting can reinforce the molecular sieve particles, thereby improving the strength performance of the molecular sieve particles.

[0079] It can be seen from Example 15, Examples 16-18 and Table 3 that the pseudo-boehmite prepared according to the conditions specified in Preparation Examples 13-15 is more helpful in improving the strength performance of the molecular sieve particles.

[0080] The above embodiments are merely explanations of the present application and are not limitations of the present application. After reading this specification, those skilled in the art may make modifications to the embodiments of the present application without any creative contribution as needed. However, as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A new type of molecular sieve specially used for electronically controlled air suspension of new energy vehicles, characterized in that: The molecular sieve is formed by sintering raw material balls, and the raw material balls include the following components in parts by weight: 100-110 parts of molecular sieve raw powder, 20-25 parts of attapulgite, 3-5 parts of calcined coal gangue powder, 2.5-3.5 parts of porous silicon carbide nanosheets, 3-5 parts of pore formers, 30-35 parts of adhesives, 8-10 parts of peptizers, 2-3 parts of molding aids, and 15-18 parts of water; the adhesive includes pseudo-boehmite and sodium carboxymethyl cellulose, and the molding aid is sesbania powder.

2. The molecular sieve specially used for electronically controlled air suspension of new energy vehicles according to claim 1 is characterized in that: The calcined coal gangue powder is prepared according to the following method: The gangue is crushed, the crushed product is ground and sieved to obtain gangue powder, the gangue powder and sodium carbonate are mixed and ground to obtain a mixture, the mixture is calcined, and the calcined product is then put into a sulfuric acid solution for oil bath heating, and then filtered, and the filter residue is washed and dried to obtain calcined gangue powder.

3. The molecular sieve specially used for electronically controlled air suspension of new energy vehicles according to claim 2 is characterized in that: The calcination temperature of the mixed material is 750-820°C.

4. The molecular sieve specially used for electronically controlled air suspension of new energy vehicles according to claim 3 is characterized in that: The weight ratio of the coal gangue to sodium carbonate is 1:(0.65-0.75).

5. The molecular sieve specially used for electronically controlled air suspension of new energy vehicles according to claim 1 is characterized in that: The porous silicon carbide nanosheets are prepared according to the following method: (1) Mixing graphite flakes, silicon monoxide, and silicon element with water to obtain a slurry, ultrasonically dispersing the slurry, and then drying it to obtain a precursor for later use; (2) The precursor is calcined in an inert atmosphere, and the calcined product is immersed in a mixed acid solution prepared by hydrofluoric acid and nitric acid. After the immersion, it is filtered, the filter residue is washed, and then calcined in an air atmosphere to obtain a porous silicon carbide nanosheet.

6. The molecular sieve specially used for electronically controlled air suspension of new energy vehicles according to claim 5 is characterized in that: The graphite sheet is prepared according to the following method: Under the protection of an inert atmosphere, expandable graphite is added to an alumina crucible for heating and expansion to obtain expanded graphite, and the expanded graphite and polyoxyethylene ether are added to deionized water to obtain a graphite dispersion, which is sand-milled and then filtered, and the filter cake is washed and dried to obtain a graphite sheet.

7. The molecular sieve specially used for electronically controlled air suspension of new energy vehicles according to claim 6 is characterized in that: The D of the graphene sheet 50 The particle size is 40-70μm.

8. The molecular sieve specially used for electronically controlled air suspension of new energy vehicles according to claim 1 is characterized in that: The pore former includes rice husk powder.

9. The molecular sieve specially used for electronically controlled air suspension of new energy vehicles according to claim 1 is characterized in that: The pseudo-boehmite is prepared according to the following method: The sodium aluminate solution and the aluminum sulfate solution are mixed, reacted at 60-70°C and pH=6.5-8.0, and after the reaction is completed, allowed to stand and age for 60-120 minutes, and then filtered. The filter cake is washed with deionized water, and then the filter cake is dried and crushed to obtain pseudo-boehmite.

10. The preparation process of the molecular sieve specially used for electronically controlled air suspension of new energy vehicles according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Mixing molecular sieve raw powder, attapulgite, calcined coal gangue powder, porous silicon carbide nanosheets, pore-forming agent, and molding aid to obtain material A, which is set aside; mixing a binder and water to obtain material B, which is set aside; (2) Add material A and material B into a granulator and mix them. After granulation, raw material balls are obtained. The raw material balls are dried and then roasted in a muffle furnace. After roasting, the raw material balls are cooled to obtain a molecular sieve specially used for electronically controlled air suspension of new energy vehicles.

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