Self-forming X-type molecular sieve foam material as well as preparation method and application thereof

Abstract

The invention discloses a self-forming X-type molecular sieve foam material as well as a preparation method and application thereof, and belongs to the field of green synthesis of molecular sieve foam materials. The preparation method comprises the following steps: 1) mixing calcined and activated metakaolin and clinoptilolite powder to obtain a solid-phase raw material, and controlling the molar ratio of SiO2 / Al2O3 to be 2.2-4; 2) mixing the solid phase raw material with 8-12 mol / L sodium hydroxide solution according to the mass ratio of (0.64-1.4): 1; and adding a foaming agent, uniformly stirring, pouring into a mold, sealing, and crystallizing at 70-100 DEG C for 16-24 hours to obtain the self-forming X-type molecular sieve foam material. The binder-free self-forming X-type molecular sieve foam is obtained only by using natural minerals and adding no chemical reagent as a silicon-aluminum source, the problems of pore channel blockage, molecular sieve effective site dilution, guest molecule transmission limitation and the like can be effectively avoided, the natural minerals can be effectively utilized, the cost is reduced, and industrial application is promoted.

Description

Technical Field

[0001] The present invention belongs to the field of green synthesis of molecular sieve foams, and specifically relates to a self-shaped X-type molecular sieve foam material, a preparation method thereof, and an application thereof. Background Art

[0002] X-type molecular sieve (structure FAU, typical chemical formula Na 86 [Al 86 Si 106 O 384 ·264H 2 O) is a high-aluminum molecular sieve with an SiO 2 / Al 2 O 3 ratio of 2.2 to 3.0, second only to the lowest A-type molecular sieve (SiO 2 / Al 2 O 3 ratio = 2), but its specific surface area is larger than that of the A-type molecular sieve. The X-type molecular sieve has a rich Si-O-Al structure, is rich in exchangeable Na ions, and has OH functional groups on its surface. Its pore diameter adsorbs molecules smaller than any molecule, and can be used as a catalyst co-carrier, for the co-adsorption of water and carbon dioxide, the co-adsorption of water and hydrogen sulfide gas, and is also applied to the drying of medicine and air compression systems. There are different professional varieties according to different applications.

[0003] The traditional synthesis method of X-type molecular sieve is to synthesize it by hydrothermal method using chemical reagents, which is costly. To solve this problem, researchers at home and abroad have made certain progress in the synthesis technology and methods of molecular sieves, and use natural mineral raw materials as the silicon-aluminum source to synthesize molecular sieves to reduce costs. For example, calcined kaolin is used as the raw material as the silicon-aluminum source, and X-type molecular sieve can be prepared by adding a chemical reagent silicon source to adjust the system composition. However, the molecular sieves synthesized by hydrothermal method using chemical reagents or mineral raw materials are usually extremely fine powder-like products with diameters in the nanometer or micrometer range, which are difficult to directly apply. Except for a few uses such as preparing detergents that require powdered molecular sieves, industrial applications generally require the molecular sieves to be processed into a shaped form to meet the impact requirements of fluids and temperatures. The shaping process requires the addition of a binder, and the molecular sieves are granulated or extruded into spherical or strip-shaped molecular sieves. However, the addition of the binder will block the pores between the molecular sieves to a certain extent, cover their active sites, and at the same time limit the amount of active components in the molecular sieves, ultimately resulting in a reduction in the adsorption performance, catalytic performance, and thermal stability of the molecular sieves.

[0004] At the same time, most of the existing methods for synthesizing molecular sieves using mineral raw materials as silicon-aluminum sources use a single mineral as the raw material and are formulated with chemical silicon-aluminum reagents for synthesis. It is difficult to synthesize molecular sieves using only two minerals as raw materials. The difficulties are as follows: There are many natural minerals, such as kaolin, clinoptilolite, bentonite, rectorite, attapulgite, illite, diatomite, etc. The mineral compositions of these mineral raw materials are complex. For example, natural rectorite contains associated minerals such as mica, pyrophyllite, chlorite, kaolinite, pyrite, rutile, etc. Although these associated minerals contain silicon-aluminum components in different proportions, most of their mineral properties are relatively stable and may not be able to provide active silicon-aluminum to participate in the reaction of molecular sieves, resulting in the inability to obtain crystalline molecular sieves. By using a single mineral and supplementing silicon-aluminum reagents, the utilization rate of natural minerals can be improved, and the types and varieties of molecular sieves synthesized from natural minerals are also greatly broadened. However, these chemical silicon-aluminum sources are obtained through complicated reactions and separations, which are typical processes with high energy consumption, high pollution emissions, and non-green characteristics. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technical means, the purpose of the present invention is to provide a self-forming X-type molecular sieve foam material, its preparation method and application. Only using natural minerals metakaolin and clinoptilolite, without adding any chemical reagents as silicon-aluminum sources, a self-forming X-type molecular sieve foam without a binder can be obtained, which can effectively avoid problems such as pore blockage, dilution of effective sites of molecular sieves, and limited transmission of guest molecules.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] Provide a preparation method of a self-forming X-type molecular sieve foam material, comprising the following steps:

[0008] 1) Mix the calcined and activated metakaolin and clinoptilolite powders to obtain a solid-phase raw material, wherein the molar ratio of SiO 2 / Al 2 O 3 in the solid-phase raw material is controlled within the range of 2.2 - 4.0;

[0009] 2) Mix the solid-phase raw material obtained in step 1) with an alkaline activator according to a mass ratio of 0.64 - 1.40:1 and stir well. The alkaline activator is an 8 - 12 mol / L sodium hydroxide solution; then add a foaming agent, stir well and pour it into a mold and seal it, and crystallize it at 70 - 100 °C for 16 - 24 h to obtain the self-forming X-type molecular sieve foam material.

[0010] According to the above scheme, in step 1), the calcined and activated metakaolin is prepared by calcining kaolin at 750 - 950 °C for 2 - 4 h.

[0011] According to the above solution, in step 1), the clinoptilolite powder is obtained by crushing and grinding natural clinoptilolite through a 60-mesh sieve.

[0012] According to the above solution, the concentration of the sodium hydroxide solution is 9 - 11 mol / L; the mass ratio of the solid-phase raw material to the alkaline activator is 0.81 - 1.22:1.

[0013] According to the above solution, in step 2), the alkaline activator is obtained by mixing sodium hydroxide and water in a mass ratio of 1:2.084 - 3.124 to obtain an 8 - 12 mol / L sodium hydroxide solution.

[0014] According to the above solution, in step 2), the foaming agent is hydrogen peroxide; preferably, the concentration of hydrogen peroxide is 20 - 30 wt%.

[0015] According to the above solution, in step 2), the added mass of the foaming agent is 2 - 6 wt% of the solid-phase raw material.

[0016] Provide a self-forming X-type zeolite foam material prepared by the above preparation method.

[0017] According to the above solution, the self-forming X-type zeolite foam material is a three-dimensional self-forming foam structure, with a specific surface area of 129 - 230 m 2 ·g -1 ; and the compressive strength is 1.26 - 2.19 MPa.

[0018] Provide an application of the above self-forming X-type zeolite foam material as an adsorbent.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. The present invention provides a preparation method of a self-forming X-type zeolite foam material. By screening two suitable natural minerals, kaolin and clinoptilolite, as the total silicon-aluminum source, regulating the appropriate silicon-aluminum ratio, and matching the appropriate concentration of the alkaline activator and the solid-liquid ratio, it can ensure that the crystalline clinoptilolite and its associated minerals are dissolved and participate in the formation of the X-type zeolite, and maintain the appropriate fluidity of the slurry, ensuring that the later foaming does not rupture; finally, through the appropriate crystallization time and crystallization temperature, a self-forming X-type zeolite foam is prepared; the present invention directly obtains a three-dimensional self-forming foam structure without a binder, which can effectively avoid problems such as pore blockage, dilution of the effective sites of the zeolite, and limited transmission of guest molecules. Moreover, the obtained foam has a large specific surface area and compressive strength, which is beneficial to the adsorption performance of the foam as an adsorbent and the recycling of the adsorbent, and has important application prospects.

[0021] 2. The preparation method of the present invention has a simple process, mild conditions, and does not require chemical reagents as the silicon-aluminum source. It can effectively utilize natural minerals, reduce costs, and is conducive to industrial application. Description of the Drawings

[0022] Figure 1 Photograph (a) of the self-forming X-type zeolite foam material prepared in Examples 1-6 and its optical microscope photograph (b).

[0023] Figure 2 XRD diffraction patterns (a) of clinoptilolite and kaolin raw materials and XRD diffraction patterns (b) of the self-forming X-type zeolite foam prepared in Examples 1-6.

[0024] Figure 3 SEM images of the self-forming X-type zeolite foam prepared in Examples 1-6.

[0025] Figure 4 XRD diffraction patterns of the foams prepared in Comparative Examples 1-3. Detailed Description of the Invention

[0026] For the purpose, technical solution and advantages of the present invention to be more clear and to enable those skilled in the art to better understand the process scheme of the present invention, the specific embodiments are as follows:

[0027] Example 1

[0028] A preparation method of a self-forming X-type zeolite foam material is provided, including the following steps:

[0029] (1) Preparation of the mixed mineral raw material: The natural clinoptilolite is crushed and ground through a 60-mesh sieve to obtain clinoptilolite powder. The kaolin is calcined at 750 °C for 2 h to prepare metakaolin. Through XRF testing, it is known that the SiO 2 content of the clinoptilolite powder is 65%, and the Al 2 O 3 content is 15%; the SiO 2 content of the metakaolin powder is 48%, and the Al 2 O 3 content is 44%. According to this composition, the clinoptilolite powder (26 g) and metakaolin (14 g) are mixed in a mass ratio of 7:13, so that the molar ratio of SiO 2 / Al 2 O 3 of the mixed raw material is 4.0, and this raw material is the raw material for preparing the self-forming X-type zeolite foam.

[0030] (2) Preparation of sodium hydroxide solution: Mix water (29.06 g) and sodium hydroxide (9.3 g) in a mass ratio of 3.124:1, stir evenly and cool to room temperature to obtain an 8 mol / L alkaline activator for molecular sieve synthesis.

[0031] (3) Preparation of self-forming X-type zeolite foam material: Mix the solid-phase raw materials (40 g) and the alkaline activator (40 g) in a mass ratio of 1:1.0 and stir evenly. Then add 1.4 g of 30 wt% hydrogen peroxide foaming agent, stir evenly and pour into a mold and seal it. Place it in an electrothermal blast drying oven and crystallize at 70 °C for 24 h to obtain a pure-phase self-forming X-type zeolite foam environmental protection material ( Figure 2 b), with a specific surface area of 129.73 m 2 ·g -1 , and a compressive strength of 1.26 MPa.

[0032] Example 2

[0033] A preparation method of a self-forming X-type zeolite foam material is provided, including the following steps:

[0034] (1) Preparation of mixed mineral raw materials: Crush and grind natural clinoptilolite through a 60-mesh sieve to obtain clinoptilolite powder. Calcinate kaolin at 850 °C for 2 h to prepare metakaolin. Through XRF testing, it can be known that the SiO 2 content of clinoptilolite powder is 65%, and the Al 2 O 3 content is 15%; the SiO 2 content of metakaolin powder is 48%, and the Al 2 O 3 content is 44%. According to this composition, mix clinoptilolite powder (26 g) and metakaolin (14 g) in a mass ratio of 7:13 to make the molar ratio of SiO 2 / Al 2 O 3 of the mixed raw materials be 4.0. This raw material is the raw material for preparing self-forming X-type zeolite foam.

[0035] (2) Preparation of sodium hydroxide solution: Mix water (19.38 g) and sodium hydroxide (9.3 g) in a mass ratio of 2.084:1, stir evenly and cool to room temperature to obtain a 12 mol / L alkaline activator for molecular sieve synthesis.

[0036] (3) Preparation of self - forming X - type zeolite foam material: Mix the solid raw materials (40 g) and the alkaline activator (28.68 g) according to a mass ratio of 1.4:1 and stir well. Then add 1.6 g of hydrogen peroxide (30 wt%) foaming agent. After stirring evenly, pour it into a mold, seal it, and place it in an electro - thermal blast drying oven. Crystallize at 80 °C for 24 h to obtain a pure - phase self - forming X - type zeolite foam environmental protection material ( Figure 2 b), with a specific surface area of 169.81 m 2 ·g -1 , and a compressive strength of 1.40 MPa.

[0037] Example 3

[0038] Provide a preparation method of self - forming X - type zeolite foam material, including the following steps:

[0039] (1) Preparation of mixed mineral raw materials: Crush and grind natural clinoptilolite through a 60 - mesh sieve to obtain clinoptilolite powder. Calcinate kaolin at 950 °C for 2 h to prepare metakaolin. Through XRF testing, it can be known that the SiO 2 content of clinoptilolite powder is 65%, and the Al 2 O 3 content is 15%; the SiO 2 content of metakaolin powder is 48%, and the Al 2 O 3 content is 44%. According to this composition, mix clinoptilolite powder (30 g) and metakaolin (20 g) according to a mass ratio of 11:15, so that the molar ratio of SiO 2 / Al 2 O 3 of the mixed raw materials is 3.6. This raw material is the raw material for preparing self - forming X - type zeolite foam.

[0040] (2) Preparation of sodium hydroxide solution: Mix water (32.5 g) and sodium hydroxide (11.7 g) according to a mass ratio of 2.77:1, stir well and cool to room temperature to obtain a 9 mol / L alkaline activator for zeolite synthesis.

[0041] (3) Preparation of self - forming X - type zeolite foam material: Mix the solid raw materials (52 g) and the alkaline activator (44.2 g) according to a mass ratio of 1.17:1 and stir well. Then add 1.8 g of hydrogen peroxide (30 wt%) foaming agent. After stirring evenly, pour it into a mold, seal it, and place it in an electro - thermal blast drying oven. Crystallize at 90 °C for 18 h to obtain a pure - phase self - forming X - type zeolite foam environmental protection material ( Figure 2 b), with a specific surface area of 189.26 m 2 ·g -1 , and a compressive strength of 1.66 MPa.

[0042] Example 4

[0043] Provided is a preparation method of a self-forming X-type molecular sieve foam material, comprising the following steps:

[0044] (1) Preparation of mixed mineral raw materials: Natural clinoptilolite is crushed and ground through a 60-mesh sieve to obtain clinoptilolite powder. Kaolin is calcined at 750 °C for 2 h to prepare metakaolin. It can be known from XRF test that the SiO 2 content of clinoptilolite powder is 65%, and the Al 2 O 3 content is 15%; the SiO 2 content of metakaolin powder is 48%, and the Al 2 O 3 content is 44%. According to this composition, clinoptilolite powder (20 g) and metakaolin (26 g) are mixed so that the molar ratio of SiO 2 / Al 2 O 3 in the mixed raw materials is 3.0. This raw material is the raw material for preparing the self-forming X-type molecular sieve foam.

[0045] (2) Preparation of sodium hydroxide solution: Water (41.67 g) and sodium hydroxide (15 g) are mixed and stirred evenly and cooled to room temperature to obtain a 9 mol / L alkaline activator for molecular sieve synthesis.

[0046] (3) Preparation of self-forming X-type molecular sieve foam material: The solid-phase raw materials (69 g) and the alkaline activator (85 g) are mixed according to a mass ratio of 0.81:1 and stirred evenly. Subsequently, 2.0 g of 30 wt% hydrogen peroxide foaming agent is added, and after stirring evenly, it is poured into a mold and sealed, and then placed in an electrothermal blast drying oven and crystallized at 90 °C for 16 h to obtain a pure-phase self-forming X-type molecular sieve foam environmental protection material ( Figure 2 b), with a specific surface area of 182.36 m 2 ·g -1 , and a compressive strength of 2.19 MPa.

[0047] Example 5

[0048] Provided is a preparation method of a self-forming X-type molecular sieve foam material, comprising the following steps:

[0049] (1) Preparation of mixed mineral raw materials: Natural clinoptilolite is crushed and ground through a 60-mesh sieve to obtain clinoptilolite powder. Kaolin is calcined at 950 °C for 2 h to prepare metakaolin. It can be known from XRF test that the SiO 2 content of clinoptilolite powder is 65%, and the Al 2 O 3 content is 15%; the SiO2 Content: 48% Al 2 O 3 Content: 44%. Based on this composition, clinoptilolite powder (15 g) and metakaolin (32.5 g) are mixed so that the molar ratio of SiO 2 / Al 2 O 3 in the mixed raw materials is 2.6. This raw material is the raw material for preparing self - shaping X - type zeolite molecular sieve foam.

[0050] (2) Preparation of sodium hydroxide solution: Water (55.28 g) and sodium hydroxide (19.9 g) are mixed, stirred evenly and cooled to room temperature to obtain a 9 mol / L alkaline activator for zeolite synthesis.

[0051] (3) Preparation of self - shaping X - type zeolite molecular sieve foam material: The solid - phase raw material (48 g) and the alkaline activator (75 g) are mixed according to a mass ratio of 0.64:1 and stirred evenly. Then 1.9 g of 30 wt% hydrogen peroxide foaming agent is added. After stirring evenly, it is poured into a mold and sealed, and then placed in an electro - thermal blast drying oven and crystallized at 100 °C for 16 h to obtain a pure - phase self - shaping X - type zeolite molecular sieve foam environmental protection material ( Figure 2 b), with a specific surface area of 179.88 m 2 ·g -1 and a compressive strength of 1.49 MPa.

[0052] Example 6

[0053] A preparation method of a self - shaping X - type zeolite molecular sieve foam material is provided, including the following steps:

[0054] (1) Preparation of mixed mineral raw materials: Natural clinoptilolite is crushed and ground through a 60 - mesh sieve to obtain clinoptilolite powder. Kaolin is calcined at 950 °C for 2 h to prepare metakaolin. Through XRF testing, it is known that the SiO 2 content in clinoptilolite powder is 65%, and the Al 2 O 3 content is 15%; the SiO 2 content in metakaolin powder is 48%, and the Al 2 O 3 content is 44%. Based on this composition, clinoptilolite powder (30 g) and metakaolin (39 g) are mixed so that the molar ratio of SiO 2 / Al 2 O 3 in the mixed raw materials is 3.0. This raw material is the raw material for preparing self - shaping X - type zeolite molecular sieve foam.

[0055] (2) Preparation of sodium hydroxide solution: Mix water (41.67 g) and sodium hydroxide (15 g), stir evenly and cool to room temperature to obtain a 9 mol / L alkaline activator for molecular sieve synthesis.

[0056] (3) Preparation of self-shaped X-type molecular sieve foam material: Mix the solid-phase raw materials (69 g) and the alkaline activator (56.69 g) according to a mass ratio of 1.217:1.0 and stir evenly. Then add 1.38 g of hydrogen peroxide (30 wt%) foaming agent, stir evenly, pour it into a mold and seal it, and put it into an electrothermal blast drying oven. Crystallize at 80 °C for 24 h to obtain a pure-phase self-shaped X-type molecular sieve foam environmental protection material ( Figure 2 b), specific surface area 229.13 m 2 ·g -1 , compressive strength 1.68 MPa.

[0057] Comparative Example 1

[0058] (1) Preparation of mixed mineral raw materials: Crush and grind natural clinoptilolite through a 60-mesh sieve to obtain clinoptilolite powder. Calcinate natural rectorite at 750 °C for 2 h to prepare activated rectorite. Mix clinoptilolite powder (26 g) and activated rectorite (14 g) according to a mass ratio of 7:13 to make the molar ratio of SiO 2 / Al 2 O 3 of the mixed raw materials be 4.0.

[0059] (2) Preparation of sodium hydroxide solution: Mix water (29.06 g) and sodium hydroxide (9.3 g) according to a mass ratio of 3.124:1, stir evenly and cool to room temperature to obtain an alkaline activator for molecular sieve synthesis.

[0060] (3) Preparation of foam material: Mix the solid-phase raw materials (40 g) and the alkaline activator (40 g) according to a mass ratio of 1:1.0 and stir evenly. Then add 1.4 g of 30 wt% hydrogen peroxide foaming agent, stir evenly, pour it into a mold and seal it, and put it into an electrothermal blast drying oven. Crystallize at 70 °C for 24 h. In addition to sodalite, rutile, and cancrinite, the product also contains a small amount of mica.

[0061] Comparative Example 2

[0062] (1) Preparation of mixed mineral raw materials: Crush and grind natural clinoptilolite through a 60-mesh sieve to obtain clinoptilolite powder. Calcinate natural rectorite at 850 °C for 2 h to prepare activated rectorite. Mix clinoptilolite powder (26 g) and activated rectorite (14 g) according to a mass ratio of 7:13 to make the molar ratio of SiO 2 / Al 2 O 3The molar ratio is 4.0.

[0063] (2) Preparation of sodium hydroxide solution: Mix water (19.38 g) and sodium hydroxide (9.3 g) in a mass ratio of 2.084:1, stir evenly and cool to room temperature to obtain an alkaline activator for molecular sieve synthesis.

[0064] (3) Preparation of foam material: Mix the solid-phase raw materials (40 g) and the alkaline activator (28.68 g) in a mass ratio of 1.4:1 and stir well. Then add 1.6 g of hydrogen peroxide (30 wt%) foaming agent, stir evenly and pour into a mold and seal it. Place it in an electrothermal blast drying oven and crystallize at 80 °C for 24 h. The products include sodalite, rutile, cancrinite, and also contain a small amount of mica.

[0065] Comparative Example 3

[0066] (1) Preparation of mixed mineral raw materials: Crush and grind natural clinoptilolite through a 60-mesh sieve to obtain clinoptilolite powder. Calcinate natural rectorite at 950 °C for 2 h to prepare activated rectorite. Mix clinoptilolite powder (30 g) and activated rectorite (20 g) in a mass ratio of 11:15, so that the SiO 2 / Al 2 O 3 The molar ratio is 3.6.

[0067] (2) Preparation of sodium hydroxide solution: Mix water (32.5 g) and sodium hydroxide (11.7 g) in a mass ratio of 2.77:1, stir evenly and cool to room temperature to obtain an alkaline activator for molecular sieve synthesis.

[0068] (3) Preparation of foam material: Mix the solid-phase raw materials (52 g) and the alkaline activator (44.2 g) in a mass ratio of 1.17:1 and stir well. Then add 1.8 g of hydrogen peroxide (30 wt%) foaming agent, stir evenly and pour into a mold and seal it. Place it in an electrothermal blast drying oven and crystallize at 90 °C for 18 h. The products include sodalite, rutile, cancrinite, and also contain a small amount of mica.

[0069] Figure 1 Photographs of the self-forming X-type molecular sieve foam materials prepared in Examples 1-6 (a) and their optical microscope photographs (b). The figure shows that the diameter of the self-forming X-type molecular sieve foam material is about 4 cm, which is consistent with the mold specifications used. The material has no size shrinkage, the pore size of the foam is about 1-2 mm, relatively uniform, and as the content of the foaming agent increases, the pore size increases relatively.

[0070] Figure 2XRD diffraction patterns of clinoptilolite and kaolin raw materials (a) and XRD diffraction patterns of self-shaped X-type zeolite foam prepared in Examples 1-6 (b). Figure 2 a shows that in addition to clinoptilolite, the natural clinoptilolite ore used is also associated with feldspar, montmorillonite, illite, and kaolinite minerals. The kaolin contains kaolinite minerals, and none of these minerals exist in the prepared product. The product is a pure-phase X-type zeolite.

[0071] Figure 3 SEM images of self-shaped X-type zeolite foam prepared in Examples 1-6. The figure shows that the morphology of the prepared X-type zeolite is granular (quasi-octahedral) and evenly distributed X-type zeolite, which is a typical morphology of X-type zeolite.

[0072] Figure 4 XRD diffraction patterns of the foam prepared in Comparative Examples 1-3. The figure shows that the product is a mixture of sodalite, rutile, cancrinite, and mica, and X-type zeolite cannot be obtained.

[0073] It can be seen from Comparative Examples 1-3 that there are many types of natural minerals. Although the chemical compositions of different natural minerals are similar, the mineral composition and active silica-alumina have a great influence on the synthesis of zeolites. It is not possible to simply combine two minerals based on their chemical compositions for the synthesis of self-shaped X-type zeolite foam. The present invention provides three groups of comparative examples. Based on the similarity of the silicon-aluminum ratio composition, natural rectorite is used to replace natural kaolin and is mineral-matched with natural clinoptilolite to synthesize X-type zeolite, but X-type zeolite foam cannot be successfully synthesized.

[0074] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. All the technical scopes disclosed by the present invention are covered within the protection scope of the present invention.

Claims

1. A method for preparing a self-forming X-type molecular sieve foam material, characterized in that: The steps include: 1) mixing calcined activated metakaolin and clinoptilolite powders to obtain a solid raw material, wherein the molar ratio of SiO2 / Al2O3 in the solid raw material is controlled within a range of 2.2-4.0; 2) The solid raw material obtained in step 1) is mixed with an alkaline activator in a mass ratio of 0.64-1.40:1 and stirred thoroughly, wherein the alkaline activator is an 8-12 mol / L sodium hydroxide solution; then a foaming agent is added, stirred evenly, poured into a mold, and sealed, and crystallized at 70-100° C. for 16-24 hours to obtain a molded X-type molecular sieve foam material.

2. The preparation method according to claim 1, characterized in that: In the step 1), the calcined activated metakaolin is prepared by calcining kaolin at 750-950° C. for 2-4 hours.

3. The preparation method according to claim 1, characterized in that: In the step 1), the clinoptilolite powder is obtained by crushing natural clinoptilolite and grinding it through a 60-mesh sieve.

4. The preparation method according to claim 1, characterized in that: The concentration of the sodium hydroxide solution is 9-11 mol / L.

5. The preparation method according to claim 1, characterized in that: The mass ratio of the solid raw material to the alkaline activator is 0.81-1.22:

1.

6. The preparation method according to claim 1, characterized in that: In the step 2), the foaming agent is a hydrogen peroxide foaming agent.

7. The preparation method according to claim 1, characterized in that: In the step 2), the mass of the added foaming agent is 2-6wt% of the solid raw material.

8. A self-forming X-type molecular sieve foam material prepared by the preparation method according to any one of claims 1 to 7.

9. The self-forming X-type molecular sieve foam material according to claim 8, characterized in that: The self-forming X-type molecular sieve foam material is a three-dimensional self-forming foam structure with a specific surface area of ​​129-230m 2 ·g -1 , the compressive strength is 1.26-2.19MPa.

10. Use of the self-forming X-type molecular sieve foam material according to claim 8 as an adsorbent.

Images