Hierarchical porous material compositions and hierarchical porous materials, their preparation methods and applications

Abstract

A hierarchical porous material composition is provided, comprising separately stored component A and component B. Component A comprises the following components in parts by weight: cement 15-40; coal gasification fine slag 40-80; reinforcing particles 5-20; quicklime 0-10; gypsum 0-5; water glass 0-5. Component B comprises the following components in parts by weight: foaming agent 0.5-3. A hierarchical porous material prepared from the hierarchical porous material composition is also provided, along with its preparation method and applications. This hierarchical porous material composition and the hierarchical porous material can comprehensively utilize coal gasification fine slag and form a special four-level porous structure through the synergistic effect between the coal gasification fine slag, reinforcing particles, cement, and foaming agent, thereby obtaining a hierarchical porous material with large specific surface area, high porosity, and high strength. The preparation method of this hierarchical porous material is simple and its application areas are wide.

Description

Technical Field

[0001] This invention belongs to the field of porous materials, specifically relating to hierarchical porous material compositions, hierarchical porous materials, their preparation methods, and applications. Background Technology

[0002] Coal gasification slag is produced by the incomplete combustion of coal with oxygen or oxygen-enriched air, and can be divided into two categories: coarse slag and fine slag. Coal or coke is fed into the gasifier as raw material, and oxygen or oxygen-containing air is simultaneously introduced. The inorganic minerals in the coal undergo various physicochemical transformations, forming solid residue along with residual carbon particles. A portion of this residue, due to its higher density, enters the lower water-cooling chamber of the gasifier and sinks to the bottom, being discharged as coarse slag through the bottom slag discharge port. The coarse slag has a relatively large particle size. The finer particles are suspended in the water of the water-cooling chamber, forming black water. The syngas produced after gasification also contains some even finer particles. This portion of the gas, after dust removal, is collected and discharged along with the black water. After pressure filtration, a black water filter cake is formed, producing fine coal gasification slag. Fine coal gasification slag is characterized by large stockpiles, large production volumes, urgent need for treatment, and its unique properties of being rich in aluminum, silicon, and carbon resources. Due to its high carbon and moisture content, coal gasification slag faces challenges in its application in building materials, including low dosage and poor environmental and economic benefits. Therefore, it is urgent to develop efficient utilization methods for coal gasification slag.

[0003] Inorganic porous materials possess characteristics such as low relative density, high porosity, light weight, sound insulation, heat insulation, and good permeability, and have broad application prospects in aerospace, aviation, chemical, building materials, metallurgy, atomic energy, petrochemical, machinery, pharmaceutical, and environmental protection fields. Existing inorganic macroporous materials, containing only micron-sized macropores, face the problem of low specific surface area and low porosity. Commonly used methods to increase specific surface area and porosity include template methods, pore-forming agent methods, and powder sintering methods; however, these methods all face the technical contradiction between porosity and strength. Increased porosity corresponds to a decrease in the strength of porous materials, significantly limiting their performance and application areas. CN 112604655 A discloses an application of coal-based gasification slag, a composite porous adsorption substrate, and its preparation method. It utilizes silicate cement, coal-based gasification slag, lime, zeolite powder, sodium silicate, and aluminum powder to prepare a composite porous adsorption substrate. The obtained material has two types of pores; it is used for water storage and retention in water bodies and for fixing vegetation roots, adsorbing heavy metals and micron-sized pollutants in the water. However, it only has a large pore structure of 0.2-1.5mm, and the coal-based gasification slag it uses is only the coarse coal gasification slag, without providing a technical solution for the comprehensive utilization of the fine coal gasification slag.

[0004] There are no existing reports on technologies for obtaining materials with multi-level porous structures using coal gasification fine slag. Summary of the Invention

[0005] The first objective of this invention is to provide a hierarchical porous material composition that utilizes coal gasification fine slag and can be used to prepare hierarchical porous materials.

[0006] A second objective of this invention is to provide a hierarchical porous material prepared using the aforementioned hierarchical porous material composition;

[0007] A third objective of this invention is to provide a method for preparing the aforementioned hierarchical porous material;

[0008] The fourth object of the present invention is to provide an application of the aforementioned hierarchical porous material.

[0009] To achieve the first objective of this invention, the following technical solution is adopted:

[0010] A hierarchical porous material composition comprising separately preserved component A and component B;

[0011] Component A comprises the following components in parts by weight:

[0012]

[0013] Component B comprises the following components in parts by weight:

[0014] Foaming agent 0.5-3; for example 0.7, 1, 1.2, 1.5, 1.7, 2, 2.2, 2.5 and 2.7.

[0015] The multi-level porous material composition of the present invention utilizes coal gasification fine slag and can be used to prepare multi-level porous materials with a multi-level porous structure, high porosity, and large specific surface area.

[0016] In one embodiment, the median particle size D50 of the coal gasification fine slag is 15-45 μm, such as 20 μm, 25 μm, 30 μm, 35 μm, 40 μm and 45 μm.

[0017] In one embodiment, the specific surface area of ​​the coal gasification fine slag is 60-300 m². 2 / g, for example, 60m 2 / g、70m 2 / g、80m 2 / g, 100m 2 / g、110m 2 / g、120m 2 / g、130m 2 / g, 140m 2 / g, 150m 2 / g、160m 2 / g、170m 2 / g、180m 2 / g、190m 2 / g、200m 2 / g、210m 2 / g、220m 2 / g、260m 2 / g and 280m 2 / g.

[0018] In one embodiment, the average pore size of the coal gasification fine slag is 2-12 nm, such as 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, 5 nm, 5.5 nm, 6 nm, 6.5 nm, 7 nm, 7.5 nm, 8 nm, 8.5 nm, 9 nm and 11 nm.

[0019] In one embodiment, the reinforcing particles are any one or more combinations of coal gasification coarse slag, fly ash, coal gangue, and bottom ash.

[0020] In one embodiment, the foaming agent is a physical foaming agent or a chemical foaming agent;

[0021] Preferably, the physical foaming agent is a protein foaming agent;

[0022] Preferably, the chemical foaming agent is any one or a combination of hydrogen peroxide, aluminum powder, and sodium bicarbonate.

[0023] To achieve the second objective of the present invention, a multi-level porous material prepared using the aforementioned multi-level porous material composition is provided.

[0024] The multi-level porous material has high porosity and specific surface area, a multi-level porous structure with mesopores and macropores, and high strength.

[0025] In one embodiment, the multi-level porous material includes a first mesoporous structure, a second mesoporous structure, a first macroporous structure, and a second macroporous structure that are interconnected.

[0026] The pore size of the first mesoporous structure is 2-50nm, such as 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm and 45nm;

[0027] The pore size of the second mesoporous structure is 2-50nm, such as 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm and 45nm;

[0028] The pore size of the first macroporous structure is 10-500μm, such as 20μm, 30μm, 40μm, 50μm, 75μm, 100μm, 125μm, 150μm, 175μm, 200μm, 225μm, 250μm, 275μm, 300μm, 325μm, 350μm, 375μm, 400μm, 425μm, 450μm and 475μm;

[0029] The pore size of the second macropore structure is 100-2000nm, such as 110nm, 150nm, 200nm, 400nm, 500nm, 750nm, 1000nm, 1250nm, 1500nm, 1750nm, and 2000nm.

[0030] In one embodiment, the first mesoporous structure is a pore structure formed by the aggregation of nano-carbon particles; the second mesoporous structure is a pore structure formed by honeycomb porous carbon.

[0031] In one embodiment, the first macroporous structure is a closed-cell structure formed by foaming; the second macroporous structure is a pore structure interwoven with columnar hydrated calcium silicate and nano-carbon particles.

[0032] In the multi-level porous material, coal gasification fine slag, reinforcing particles, cement and foaming agent can work synergistically to form a special four-level porous structure. Furthermore, the specific surface area can be significantly increased without reducing compressive strength by utilizing two of the mesoporous structures, and the dry density and porosity can be significantly reduced by utilizing the first macroporous structure.

[0033] In one embodiment, the porosity of the hierarchical porous material is 45-60%, such as 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, and 59%; and / or

[0034] The specific surface area of ​​the hierarchical porous material is 30-180 m². 2 / g, for example, 30m 2 / g、40m 2 / g, 50m 2 / g、60m 2 / g、70m 2 / g、80m 2 / g、90m 2 / g, 100m 2 / g、110m 2 / g、120m 2 / g、130m 2 / g, 140m 2 / g, 150m 2 / g、160m2 / g、170m 2 / g and 180m 2 / g; and / or

[0035] The compressive strength of the hierarchical porous material is 1-20 MPa, such as 2 MPa, 4 MPa, 6 MPa, 8 MPa, 10 MPa, 12 MPa, 14 MPa, 16 MPa and 18 MPa; and / or

[0036] The water absorption rate of the hierarchical porous material is 6-35 wt%, such as 10 wt%, 15 wt%, 20 wt%, 25 wt%, and 30 wt%; and / or

[0037] The dry density of the multi-level porous material is 500-1500 kg / m³. 3 For example, 600kg / m 3 700kg / m 3 800kg / m 3 900kg / m 3 1000kg / m 3 1100kg / m 3 1200kg / m 3 1300kg / m 3 and 1400kg / m 3 .

[0038] In one embodiment, the hierarchical porous material comprises the following components: Al2O3, SiO2, CaO, Fe2O3, K2O, Na2O, MgO, and C; wherein,

[0039] Based on the total mass of Al2O3, SiO2, CaO, Fe2O3, K2O, Na2O, and MgO, the contents of Al2O3, SiO2, CaO, Fe2O3, K2O, Na2O, and MgO in the hierarchical porous material are as follows:

[0040] 8-21 wt%, such as 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, and 20 wt%;

[0041] 20-42wt%, such as 22wt%, 24wt%, 26wt%, 28wt%, 30wt%, 32wt%, 34wt%, 36wt%, 38wt%, and 40wt%;

[0042] 10-42.5 wt%, such as 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, and 40 wt%;

[0043] 8-18 wt%, such as 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, and 17 wt%;

[0044] 0.5-3wt%, such as 1wt%, 1.5wt%, 2wt%, and 2.5wt%;

[0045] 0.5-2.5wt%, such as 1wt%, 1.5wt%, and 2wt%; and

[0046] 0.5-4wt%, such as 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, and 3.5wt%;

[0047] Based on the total mass of the hierarchical porous material, the C content in the hierarchical porous material is 15-45 wt%, such as 20 wt%, 25 wt%, 30 wt%, 35 wt%, and 40 wt%.

[0048] To achieve the third objective of this invention, a method for preparing the aforementioned hierarchical porous material is provided, comprising the following steps:

[0049] (1) Mix component A in the multi-level porous material composition with water to form a slurry of component A;

[0050] (2) Mix component B in the multi-level porous material composition with water to form a slurry of component B;

[0051] (3) Add the slurry of component B obtained in step (2) to the slurry of component A obtained in step (1), mix and then form and cure to obtain a multi-level porous material;

[0052] Based on the amount of the multi-level porous material composition added, the amount of water added in step (1) is 35-62 wt%, such as 36 wt%, 38 wt%, 40 wt%, 42 wt%, 44 wt%, 46 wt%, 48 wt%, 50 wt%, 52 wt%, 54 wt%, 56 wt%, 58 wt%, and 60 wt%; and the amount of water added in step (2) is 1-8 wt%, such as 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, and 7 wt%.

[0053] Among them, coal gasification fine slag, reinforcing particles, cement and foaming agent can play a synergistic role to form a special four-level pore structure, thereby obtaining a multi-level pore structure; and the mesoporous structure can be used to significantly increase its specific surface area without reducing compressive strength, and the first macroporous structure can be used to significantly reduce dry density and increase porosity without reducing its strength.

[0054] Those skilled in the art will understand that the amount added to the hierarchical porous material composition refers to the total amount of component A and component B added to the hierarchical porous material composition.

[0055] To achieve the fourth objective of this invention, the invention also provides applications of the aforementioned multi-level porous materials or multi-level porous materials prepared according to the aforementioned preparation method in the fields of biological filter media, water treatment filter media, wetland filter media, building insulation boards, sound-absorbing boards, or porous boards.

[0056] The beneficial effects of this invention are as follows:

[0057] The multi-level porous material composition of the present invention can make comprehensive use of coal gasification fine slag and can be used to prepare multi-level porous materials with multi-level porous structure, high porosity, large specific surface area and high strength.

[0058] The multi-level porous material of this invention comprehensively utilizes coal gasification fine slag, reinforcing particles, cement, and foaming agent. These four components work synergistically to form a unique four-level porous structure. Furthermore, the mesoporous structure significantly increases the specific surface area without reducing compressive strength, while the first and second macroporous structures significantly reduce dry density and increase porosity. This overcomes the problems of low specific surface area and low porosity faced by existing inorganic macroporous materials, which contain only micron-sized macropores. It also overcomes the problem that commonly used methods in the field to increase the specific surface area and porosity of materials reduce material strength.

[0059] The method for preparing multi-level porous materials of the present invention, wherein coal gasification fine slag, reinforcing particles, cement and foaming agent can play a synergistic role to form a special four-level pore structure, thereby obtaining a multi-level porous structure; and can significantly increase the specific surface area of ​​the obtained multi-level porous material without reducing the compressive strength by utilizing the mesoporous structure therein, and significantly reduce the dry density and increase the porosity of the obtained multi-level porous material by utilizing the first macropore and second macropore structures therein;

[0060] The multi-level porous material of this invention can be applied in many fields and has a wide range of applications. Attached Figure Description

[0061] Figure 1 This is a SEM image of the first macropore structure in the multi-porous material described in Example 1;

[0062] Figure 2 This is a SEM image of the second largest pore structure in the multi-porous material described in Example 1;

[0063] Figure 3 This is a SEM image of the first mesoporous structure in the multi-level porous material described in Example 1;

[0064] Figure 4This is an SEM image of the second mesoporous structure in the multi-porous material described in Example 1. Detailed Implementation

[0065] The technical solution and its effects of the present invention will be further described below with reference to specific embodiments / examples. The following embodiments / examples are only for illustrating the content of the present invention, and the invention is not limited to the following embodiments or examples. Simple modifications made to the present invention based on the concept of the present invention are all within the scope of protection claimed by the present invention.

[0066] The main raw materials used in the following examples and comparative examples are shown in Table 1:

[0067] Table 1. Main raw materials used in the embodiments and comparative examples of the present invention.

[0068]

[0069]

[0070] The performance testing methods for porous materials are as follows:

[0071] The specific surface area was measured using the N2-adsorption-desorption method.

[0072] The compressive strength test shall be conducted in accordance with the compressive strength test method specified in JG / T 266-2011 Foamed Concrete;

[0073] The porosity was tested according to GB / T1966-1996-Test Method for Apparent Porosity and Bulk Density of Porous Ceramics;

[0074] The dry density was tested according to "JG / T 266-2011 Foamed Concrete".

[0075] Examples 1-5 (S1-5)

[0076] Multi-level porous material C1-5 was prepared according to the following method:

[0077] (1) Mix component A in the multi-level porous material composition with water to form component A slurry; wherein, component A includes the following components in parts by weight: cement 15-40; coal gasification fine slag 40-80; reinforcing particles 5-20; quicklime 0-10; gypsum 0-5; water glass 0-5; as shown in Table 2.

[0078] (2) Mix component B in the multi-level porous material composition with water to form a component B slurry; wherein, component B includes the following components in parts by weight: foaming agent 0.5-3; as shown in Table 2;

[0079] (3) Add the slurry of component B obtained in step (2) to the slurry of component A obtained in step (1), mix and then form and cure to obtain multi-level porous material C1-5;

[0080] Based on the amount of the multi-level porous material composition added, the amounts of water added in steps (1) and (2) are shown in Table 2.

[0081] Comparative Example 1-2 (D1-2)

[0082] Material C1'-2' was prepared according to the following method:

[0083] (1) Mix component 1 and component 2 with water to form a first slurry; wherein, component 1 and component 2 are specifically shown in Table 3;

[0084] (2) Mix the foaming agent with water to form a second slurry; wherein the specific foaming agent is shown in Table 3;

[0085] (3) Add the second slurry obtained in step (2) to the first slurry obtained in step (1), mix and then form and cure to obtain the multi-level porous material C1'-2';

[0086] Based on the total amount of component 1, component 2 and foaming agent added, the amount of water added in steps (1) and (2) is shown in Table 3.

[0087] The formulations and dosages in Examples 1-5 (S1-5) and Comparative Examples 1-2 (D1-2) are shown in Tables 2 and 3, respectively. The performance test results of the obtained hierarchical porous materials C1-5 and C1'-2' are shown in Table 4.

[0088] Table 2. Formulations, dosages, and curing methods for preparing hierarchical porous material C1-5 in Examples 1-75 (S1-5).

[0089]

[0090]

[0091] Table 3 shows the formulations, dosages, and curing methods for preparing hierarchical porous material C1'-2' in Comparative Example 1-2 (D1-2).

[0092]

[0093] Table 4 shows the performance test results of the hierarchical porous materials C1-5 and C1'-2' used in Examples 1-5 (S1-5) and Comparative Examples 1-2 (D1-2).

[0094]

[0095] SEM images of the four pore structures in the hierarchical porous material C1 obtained in Example 1 are shown below. Figure 1-4 , Figure 1-4 The area circled in the middle represents the corresponding hole structure.

[0096] according to Figure 1-4 It can be seen that all four pore structures exist in the multi-porous material obtained in Example 1.

[0097] As can be seen from the comparison of Examples 1-5 and Comparative Examples 1-2 in Tables 1-4, the multi-level porous material of the present invention comprehensively utilizes coal gasification fine slag, reinforcing particles, cement and foaming agent, which work together synergistically to form a special four-level porous structure. Moreover, it can significantly increase its specific surface area under high compressive strength by utilizing the mesoporous structure therein, and significantly reduce dry density and increase porosity by utilizing the first macroporous structure therein. This overcomes the problem that commonly used methods in the art to increase the specific surface area and porosity of materials will reduce the strength of the materials.

Claims

1. A hierarchical porous material, characterized in that, The hierarchical porous material is prepared from a hierarchical porous material composition; wherein... The hierarchical porous material composition comprises separately preserved component A and component B; Component A comprises the following components in parts by weight: Cement 15-40; Coal gasification fine slag 40-80; Reinforcing particles 5-20; quicklime 0-10; 0.5-5 g of plaster; Water glass 0-5; Component B comprises the following components in parts by weight: Foaming agent 0.5-3; The specific surface area of ​​the coal gasification fine slag is 60-300 m². 2 / g; The median particle size D50 of the coal gasification fine slag is 15-45 μm; The average pore size of the coal gasification fine slag is 2-12 nm; The reinforcing particles are any one or more combinations of coal gasification coarse slag, fly ash, coal gangue and bottom ash; The multi-level porous material includes a first mesoporous structure, a second mesoporous structure, a first macroporous structure, and a second macroporous structure that are interconnected. The pore size of the first mesoporous structure is 2-50 nm; The pore size of the second mesoporous structure is 2-50 nm; The pore size of the first macroporous structure is 10-500 μm; The pore size of the second macroporous structure is 100-2000 nm.

2. The multi-level porous material according to claim 1, characterized in that, The foaming agent is either a physical foaming agent or a chemical foaming agent.

3. The multi-level porous material according to claim 2, characterized in that, The physical foaming agent is a protein foaming agent.

4. The multi-level porous material according to claim 2, characterized in that, The chemical foaming agent is any one or a combination of hydrogen peroxide, aluminum powder, and sodium bicarbonate.

5. The multi-level porous material according to any one of claims 1-4, characterized in that, The porosity of the hierarchical porous material is 45-60%; and / or The specific surface area of ​​the hierarchical porous material is 30-180 m². 2 / g; and / or The compressive strength of the hierarchical porous material is 1-20 MPa; and / or The dry density of the hierarchical porous material is 500-1500 kg / m³. 3 .

6. The multi-level porous material according to any one of claims 1-4, characterized in that, The hierarchical porous material comprises the following components: Al2O3, SiO2, CaO, Fe2O3, K2O, Na2O, MgO, and C; wherein, Based on the total mass of Al2O3, SiO2, CaO, Fe2O3, K2O, Na2O, and MgO, the contents of Al2O3, SiO2, CaO, Fe2O3, K2O, Na2O, and MgO in the hierarchical porous material are 8-21 wt%, 20-42 wt%, 10-42.5 wt%, 8-18 wt%, 0.5-3 wt%, 0.5-2.5 wt%, and 0.5-4 wt%, respectively. Based on the total mass of the hierarchical porous material, the C content in the hierarchical porous material is 15-45 wt%.

7. A method for preparing a hierarchical porous material as described in any one of claims 1-6, characterized in that, The preparation method includes the following steps: (1) Mix component A in the multi-level porous material composition with water to form a slurry of component A; (2) Mix component B in the multi-level porous material composition with water to form a slurry of component B; (3) Add the slurry of component B obtained in step (2) to the slurry of component A obtained in step (1), mix and then form and cure to obtain a multi-level porous material; Based on the amount of the multi-level porous material composition added, the amount of water added in step (1) is 35-62 wt%, and the amount of water added in step (2) is 1-8 wt%.

8. The application of the multi-level porous material as described in any one of claims 1-6 or the multi-level porous material prepared by the preparation method according to claim 7 in the fields of biological filter media, water treatment filter media, wetland filter media, building insulation boards, sound-absorbing boards, or porous boards.

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