Coal mine grouting and air leakage plugging material and preparation method thereof

Abstract

The invention discloses a coal mine grouting and plugging air leakage material, relating to a mine plugging air leakage material, comprising three parts: material A, material B, and material C, wherein the weight ratio of material A, material B, and material C is 1:1:1; the material A comprises, by weight, 5-8 parts fly ash, 4-6 parts composite filler, 1-1.5 parts sodium silicate, 5-6 parts cross-linking agent, and 5-6 parts water; the material B comprises, by weight, 1-1.2 parts composite foaming agent, 0.5-0.8 parts foam stabilizer, and 40-48 parts water; and the material C comprises, by weight, 1.5-2 parts sodium carboxymethyl cellulose and 100 parts water. The material has low cost, large coverage area, excellent water retention, and good plugging effect.

Description

Technical Field

[0001] The invention relates to a mine air leakage plugging material, in particular to a coal mine grouting air leakage plugging material and a preparation method thereof. Background Art

[0002] Coal spontaneous combustion is one of the main natural disasters faced during coal mining in mines. One of the main factors for coal spontaneous combustion is air leakage. Under the conditions of ventilation and oxygen supply, coal in coal mines is prone to spontaneous combustion. Therefore, plugging air leakage is a key technology for preventing and controlling coal spontaneous combustion. The air leakage plugging technology mainly blocks or reduces the contact between coal and oxygen to achieve the effect of fire prevention and extinguishing. For example, sealing slurry is used to spray cracks and gaps on the sealing wall in the mine, or cracks in the coal seam or broken and loose coal bodies in the goaf and fault cracks are sealed and filled.

[0003] Currently, commonly used materials for plugging air leaks in coal mines include yellow mud grouting, cement-based materials, polymer gel materials, and foam materials. Different plugging materials have varying advantages and disadvantages. For example, yellow mud grouting is low-cost and easily accessible, but it is prone to settling during transportation, exhibits poor stability, and exhibits poor consolidation and water retention. Cement-based materials such as fly ash have difficult-to-control setting times, low toughness, and are prone to shrinkage and cracking after drying, making them ineffective for long-term plugging. Polymer gel materials are relatively expensive. Furthermore, these materials tend to flow to low-lying areas and cannot accumulate in high-lying areas, making them ineffective in preventing and controlling coal in the middle, high, and roof layers. Furthermore, they are prone to gullying and have limited coverage. Foam materials, such as foamed cement, are expansive and effective in plugging air leaks. However, their stability is difficult to control, and they have a high water loss rate, which can lead to collapse and severe pulverization of the foam material, compromising their effectiveness. Therefore, developing a new, low-cost, high-spreading, large-coverage, and excellent air leak plugging material is crucial for coal mine fire prevention and extinguishing. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a coal mine grouting plugging air leakage material to address the deficiencies of the existing technology, which has low cost, large coverage area, excellent water retention performance and good plugging effect.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A coal mine grouting and plugging air leakage material consists of three parts: material A, material B, and material C. The weight ratio of material A, material B, and material C is 1:1:1. The material A comprises, in parts by weight, 5-8 parts of fly ash, 4-6 parts of composite filler, 1-1.5 parts of sodium silicate, 5-6 parts of cross-linking agent, and 5-6 parts of water. The material B comprises, in parts by weight, 1-1.2 parts of composite foaming agent, 0.5-0.8 parts of foam stabilizer, and 40-48 parts of water. The material C comprises, in parts by weight, 1.5-2 parts of sodium carboxymethyl cellulose and 100 parts of water.

[0007] Furthermore, the composite filler is a mixture of expanded vermiculite and loess in a weight ratio of 2:1.

[0008] Furthermore, the loess is loess from a mining area, which is dried and crushed, and particles with a particle size of ≤0.5 mm are sieved.

[0009] Furthermore, the cross-linking agent is a slow-release cross-linking agent, which is prepared by the following steps:

[0010] Soluble starch is dissolved in water, the temperature is raised to 50°C, acrylic acid, ammonium persulfate and aluminum citrate are added and stirred evenly, and finally acrylamide, N,N-methylenebisacrylamide and montmorillonite are added, stirred and reacted for 1 hour, and allowed to stand for 2 hours to obtain a gel product, which is then ground, granulated and sieved by a grinder to obtain a slow-release crosslinking agent with a particle size of 0.1-0.5 mm. The weight ratio of the soluble starch, acrylic acid, acrylamide, aluminum citrate, montmorillonite, ammonium persulfate and N,N-methylenebisacrylamide is 10:5:5:8-10:2:0.01:0.01.

[0011] Furthermore, the composite foaming agent is a mixture of animal protein foaming agent, sodium dodecylbenzene sulfonate, sodium α-olefin sulfonate and sodium lauryl sulfate in a weight ratio of 20:1:1:1.

[0012] Furthermore, the foam stabilizer is a mixture of lauryl alcohol, xanthan gum, and nanoparticles in a weight ratio of 2.5:0.5:1-2.

[0013] Furthermore, the nanoparticles are a mixture of nano-calcium carbonate and nano-silicon dioxide in a weight ratio of 1:1-2.

[0014] A method for preparing a coal mine grouting and air leakage plugging material comprises the following steps:

[0015] Mix the raw materials in material B and stir them evenly. Use foaming equipment to foam them. Mix material A into a uniform slurry. Mix the foam and slurry evenly. Then stir them evenly with material C and transport them for grouting.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present application discloses a coal mine grouting and plugging air leakage material, which combines sodium carboxymethyl cellulose-fly ash-based gel material and foam material. After the mixed slurry of fly ash-based material, foam and polymer material are mixed, the sodium carboxymethyl cellulose and cross-linking agent evenly distributed in the foam wall undergo a cross-linking reaction, and at the same time the fly ash-based gel material begins to hydrate, and the sodium carboxymethyl cellulose also cross-links with the metal ions dissolved in the fly ash and composite filler to form an interconnected gel network structure with a large number of pores inside. The structure has strong stability, low cost, large coverage area, strong water retention performance and excellent air leakage plugging effect.

[0018] 2. The preparation process of the air leakage plugging material of the present application is to first prepare foam, then evenly mix it with sodium carboxymethyl cellulose and fly ash-based gel material, foam it first, and then slowly form gel at the foam wall, which helps to increase the mechanical strength of the foam wall membrane, thereby increasing the stability of the foam.

[0019] 3. Composite fillers are added to fly ash, and expanded vermiculite and mining loess are used, which can be obtained locally to reduce production costs. In addition, after the expanded vermiculite and loess are fully mixed, the expanded vermiculite has strong adsorption properties, which can increase the stability of loess in the slurry.

[0020] 4. The grouting of the plugging material requires pipeline transportation. Therefore, the present application controls the time of sodium carboxymethyl cellulose gelation. The crosslinker adopts aluminum citrate as a slow-release crosslinker. The aluminum citrate is coated with a polymer prepared from soluble starch, acrylic acid, acrylamide and montmorillonite. The montmorillonite surface has a large number of hydrophilic groups, and the hydroxyl groups on its surface can react and copolymerize with the monomer to enter the network structure of the polymer, thereby increasing its water absorption and swelling properties. The aluminum citrate is dispersed in the polymer network system, which can solve the problem of excessive release of metal ions and achieve a slow-release effect.

[0021] 5. The main component of the composite foaming agent is animal protein foaming agent. In order to increase the foaming amount of the animal protein foaming agent and reduce the cost, the ionic surfactant sodium dodecylbenzene sulfonate is added to the animal protein foaming agent to reduce the surface tension of the liquid and increase the foaming ability. When the foaming amount increases, the adhesion between the foams is large and it is easy to fuse to form large bubbles and collapse. Therefore, a small amount of sodium α-olefin sulfonate and sodium dodecyl sulfate are added. The foaming pore size is relatively small, the foam pore size is uniform, and the collapse of the bubble is reduced.

[0022] 6. The foam stabilizer is a compound system composed of dodecanol, xanthan gum and nanoparticles. The hydrocarbon chain structure of the dodecanol molecule itself can reduce the surface tension of the solution, promote the formation of micelles, reduce the critical micelle concentration, and increase the amount of foam; the nanoparticles are arranged at the boundary of the foam film to delay the foam precipitation; xanthan gum can increase the viscosity of the system and increase the stability of the nanoparticles at the boundary of the foam film. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the curve diagram of water loss rate change of materials at different times;

[0024] Figure 2 This is a schematic diagram of the air leakage plugging performance test device;

[0025] Figure 3 The pressure-differential pressure curve diagram is applied for the air leakage test of this application. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the accompanying drawings and examples. Example 1

[0027] A coal mine grouting and plugging air leakage material consists of three parts: material A, material B, and material C, wherein the weight ratio of material A, material B, and material C is 1:1:1; the composition of material A, calculated by weight, includes 5 parts of fly ash, 6 parts of composite filler, 1 part of sodium silicate, 5 parts of cross-linking agent, and 5 parts of water; the composition of material B, calculated by weight, includes 1 part of composite foaming agent, 0.5 part of foam stabilizer, and 40 parts of water; and the composition of material C, calculated by weight, includes 1.5 parts of sodium carboxymethyl cellulose and 100 parts of water.

[0028] The composite filler is a mixture of expanded vermiculite and loess in a weight ratio of 2:1. The expanded vermiculite particle size is 60-80 mesh. The loess is from the mining area, dried, crushed, and sieved to obtain particles ≤0.5mm. The colloidal mixture (calculated as magnesium oxide) content of the mining area loess is 20-30%.

[0029] The cross-linking agent is a slow-release cross-linking agent, which is prepared by the following steps: dissolving soluble starch in an appropriate amount of water (the mass fraction of starch is 5%), heating to 50°C, adding acrylic acid (neutralization degree 70%), ammonium persulfate and aluminum citrate and stirring evenly (N2 environment), and finally adding acrylamide, N,N-methylenebisacrylamide and montmorillonite, stirring and reacting for 1 hour, standing for 2 hours to obtain a gel product, grinding, granulating and screening with a grinder to obtain a slow-release cross-linking agent with a particle size of 0.1-0.5 mm; the weight ratio of the soluble starch, acrylic acid, acrylamide, aluminum citrate, montmorillonite, ammonium persulfate and N,N-methylenebisacrylamide is 10:5:5:8:2:0.01:0.01.

[0030] The composite foaming agent is a mixture of animal protein foaming agent, sodium dodecylbenzene sulfonate, sodium α-olefin sulfonate and sodium lauryl sulfate in a weight ratio of 20:1:1:1. The foaming multiple of the animal protein foaming agent is 40 times and the density is 1.10 g / cm 3 .

[0031] The foam stabilizer is a mixture of lauryl alcohol, xanthan gum, and nanoparticles in a weight ratio of 2.5:0.5:1; the nanoparticles are a mixture of nano-calcium carbonate and nano-silicon dioxide in a weight ratio of 1:1; the nanoparticles used in the examples of the present application have been surface-modified, and the specific modification method is:

[0032] The nanoparticles were dispersed in three times their weight of water, and toluene (twice their weight) was added. Ultrasonic oscillation was then applied to the nanoparticles, followed by a small amount of dodecyltrimethoxysilane. The mixture was stirred at 60°C for 30 minutes, followed by the addition of a certain amount of KH550. The reaction continued for 30 minutes, followed by vacuum filtration, washing, drying, and ball milling to obtain a product with a weight ratio of 1:2:2 for the nanoparticles, dodecyltrimethoxysilane, and KH550. The nanoparticles were surface treated with dodecyltrimethoxysilane and KH550 to introduce both hydrophilic and hydrophobic groups onto their surfaces, increasing their dispersibility within the foam wall and further enhancing the foam stabilization effect.

[0033] A method for preparing a coal mine grouting and air leakage plugging material comprises the following steps:

[0034] Mix the raw materials in material B and stir them evenly. Use foaming equipment to foam them. Mix material A into a uniform slurry. Then mix the foam and slurry evenly. Then mix them evenly with material C and transport them for grouting. Example 2

[0035] A coal mine grouting and plugging air leakage material consists of three parts: material A, material B, and material C, wherein the weight ratio of material A, material B, and material C is 1:1:1; the composition of material A, calculated by weight, includes 6 parts of fly ash, 5 parts of composite filler, 1.2 parts of sodium silicate, 5.5 parts of cross-linking agent, and 5 parts of water; the composition of material B, calculated by weight, includes 1.1 parts of composite foaming agent, 0.6 parts of foam stabilizer, and 42 parts of water; and the composition of material C, calculated by weight, includes 1.6 parts of sodium carboxymethyl cellulose and 100 parts of water.

[0036] The composite filler is a mixture of expanded vermiculite and loess in a weight ratio of 2:1. The expanded vermiculite has a particle size of 60-80 mesh. The loess is from a mining area, dried, crushed, and sieved to obtain particles with a size of ≤0.5 mm. The content of the mining area loess colloid mixture (calculated as magnesium oxide) is 26%.

[0037] The cross-linking agent is a slow-release cross-linking agent, which is prepared by the following steps:

[0038] Soluble starch is dissolved in an appropriate amount of water, the temperature is raised to 50°C, acrylic acid (neutralization degree 70%), ammonium persulfate and aluminum citrate are added and stirred evenly, and finally acrylamide, N,N-methylenebisacrylamide and montmorillonite are added, stirred and reacted for 1 hour, and allowed to stand for 2 hours to obtain a gel product, which is then ground, granulated and sieved with a grinder to obtain a slow-release crosslinking agent with a particle size of 0.1-0.5 mm. The weight ratio of the soluble starch, acrylic acid, acrylamide, aluminum citrate, montmorillonite, ammonium persulfate and N,N-methylenebisacrylamide is 10:5:5:9:2:0.01:0.01.

[0039] The foaming agent is prepared by mixing an animal protein foaming agent, sodium dodecylbenzene sulfonate, sodium α-olefin sulfonate and sodium lauryl sulfate in a weight ratio of 20:1:1:1.

[0040] The foam stabilizer is a mixture of lauryl alcohol, xanthan gum and nanoparticles in a weight ratio of 2.5:0.5:1.5, wherein the nanoparticles are a mixture of nano calcium carbonate and nano silicon dioxide in a weight ratio of 1:1.5.

[0041] The other processes are the same as those in Example 1. Example 3

[0042] A coal mine grouting and plugging air leakage material consists of three parts: material A, material B, and material C, wherein the weight ratio of material A, material B, and material C is 1:1:1; the composition of material A, calculated by weight, includes 7 parts of fly ash, 5 parts of composite filler, 1.4 parts of sodium silicate, 6 parts of cross-linking agent, and 6 parts of water; the composition of material B, calculated by weight, includes 1.2 parts of composite foaming agent, 0.7 parts of foam stabilizer, and 45 parts of water; and the composition of material C, calculated by weight, includes 1.8 parts of sodium carboxymethyl cellulose and 100 parts of water.

[0043] The cross-linking agent is a slow-release cross-linking agent, which is prepared by the following steps:

[0044] Soluble starch is dissolved in water, the temperature is raised to 50°C, acrylic acid (neutralization degree 70%), ammonium persulfate and aluminum citrate are added and stirred evenly, and finally acrylamide, N,N-methylenebisacrylamide and montmorillonite are added, stirred and reacted for 1 hour, and allowed to stand for 2 hours to obtain a gel product, which is then ground, granulated and sieved with a grinder to obtain a slow-release crosslinking agent with a particle size of 0.1-0.5 mm. The weight ratio of the soluble starch, acrylic acid, acrylamide, aluminum citrate, montmorillonite, ammonium persulfate and N,N-methylenebisacrylamide is 10:5:5:9:2:0.01:0.01.

[0045] The foaming agent is prepared by mixing an animal protein foaming agent, sodium dodecylbenzene sulfonate, sodium α-olefin sulfonate and sodium lauryl sulfate in a weight ratio of 20:1:1:1.

[0046] The foam stabilizer is a mixture of lauryl alcohol, xanthan gum and nanoparticles in a weight ratio of 2.5:0.5:2, wherein the nanoparticles are a mixture of nano calcium carbonate and nano silicon dioxide in a weight ratio of 1:2.

[0047] The other processes are the same as those in Example 2. Example 4

[0048] A coal mine grouting and plugging air leakage material consists of three parts: material A, material B, and material C, wherein the weight ratio of material A, material B, and material C is 1:1:1; the composition of material A, calculated by weight, includes 8 parts of fly ash, 4 parts of composite filler, 1.5 parts of sodium silicate, 5.5 parts of cross-linking agent, and 6 parts of water; the composition of material B, calculated by weight, includes 1.1 parts of composite foaming agent, 0.8 parts of foam stabilizer, and 48 parts of water; and the composition of material C, calculated by weight, includes 2 parts of sodium carboxymethyl cellulose and 100 parts of water.

[0049] The cross-linking agent is a slow-release cross-linking agent, which is prepared by the following steps:

[0050] Soluble starch is dissolved in water, the temperature is raised to 50°C, acrylic acid (neutralization degree 70%), ammonium persulfate and aluminum citrate are added and stirred evenly, and finally acrylamide, N,N-methylenebisacrylamide and montmorillonite are added, stirred and reacted for 1 hour, and allowed to stand for 2 hours to obtain a gel product, which is then ground, granulated and sieved with a grinder to obtain a slow-release crosslinking agent with a particle size of 0.1-0.5 mm. The weight ratio of the soluble starch, acrylic acid, acrylamide, aluminum citrate, montmorillonite, ammonium persulfate and N,N-methylenebisacrylamide is 10:5:5:10:2:0.01:0.01.

[0051] The foaming agent is a mixture of animal protein foaming agent, sodium dodecylbenzene sulfonate, sodium α-olefin sulfonate, and sodium lauryl sulfate in a weight ratio of 20:1:1:1. The foam stabilizer is a mixture of lauryl alcohol, xanthan gum, and nanoparticles in a weight ratio of 2.5:0.5:1.5; the nanoparticles are a mixture of nano-calcium carbonate and nano-silicon dioxide in a weight ratio of 1:2.

[0052] The other processes are the same as those in Example 3.

[0053] Comparative Example 1

[0054] Comparative Example 1 is a comparative example of Example 4, and differs therefrom in that: Material C is not added in Comparative Example 1.

[0055] Comparative Example 2

[0056] Comparative Example 2 is a comparative example of Example 4, and differs from it in that: in Comparative Example 1, Material A consists of only one raw material: 5.5 parts of a cross-linking agent.

[0057] Comparative Example 3

[0058] The difference between Comparative Example 3 and Example 4 is that no foam stabilizer is added to the raw materials.

[0059] Comparative Example 4

[0060] The difference between Comparative Example 4 and Example 4 is that the foam stabilizer is a mixture of dodecyl alcohol and xanthan gum in a weight ratio of 5:1.

[0061] Comparative Example 5

[0062] The difference between Comparative Example 5 and Example 4 is that the foaming agent is an animal protein foaming agent.

[0063] Comparative Example 6

[0064] The difference between Comparative Example 6 and Example 4 is that the foaming agent is a mixture of animal protein foaming agent and sodium dodecylbenzenesulfonate in a weight ratio of 20:1.

[0065] Performance testing

[0066] The foaming ability and foam stability of material B in Examples 1-4 and Comparative Examples 1-6 were tested. The testing method was as follows: 100 mL of the mixed solution of material B was added to a measuring cup, stirred at 2000 r / min for 60 seconds, and then stopped. The volume of foam generated was recorded to measure the foaming ability of the solution. As time went on, liquid continued to precipitate from the foam, and the time required for the foam to defoam to half was recorded as the foam half-life, which was used to measure the stability of the foam. The test results are shown in Table 1.

[0067] The gel time, 7d compressive strength (sample size 70.7mm*70.7mm*70.7mm), water loss rate and air leakage plugging performance of the materials of Examples 1-4 and Comparative Examples 1-2 were tested.

[0068] Water loss rate test: Place the fully gelled material in a drying oven, set the temperature to 80℃, take it out and weigh it every 2 hours to test the water loss rate. The results are shown in Figure 1 .

[0069] Air leakage performance test: Test device see Figure 2 The pressure is provided by a compressed air cylinder. The cylinder is connected to one end of the pressure test tube through a pressure reducing valve, a pressure stabilizing valve and a pressure gauge. The other side of the pressure test tube is connected to a pressure gauge. The pressure test tube is 25 cm long and 12 cm in diameter. A 2.5 cm gap is left on both sides. The middle part is fixed with copper wire. The coal sample treated with the plugging material (200 g of coal particles with a particle size of 0.5-3 mm are laid on the wire mesh, 20 g of the material is sprayed on the surface of the coal particles, and after the gel is completely formed, the device is pressed Figure 2 Assemble), apply pressure to the pressure test tube, and measure the pressure difference between the two ends of the pressure test tube as the material's withstand pressure. Figure 3 .

[0070] Table 1 Performance test data

[0071]

[0072] The air leakage plugging materials prepared in Examples 1-4 of the present application have an initial setting time of 13-15 minutes and a final setting time of about 16-18 minutes, which can meet the requirements of underground transportation.

[0073] As can be seen from the data in Table 1, the foaming agent of Material B in this application has a large foaming volume, slow foam decay, and high stability. The material strength of Comparative Examples 1 and 2 is lower than that of Example 4, indicating that the cross-linked gel network structure developed in this application can increase the strength of the material.

[0074] Comparative Examples 3-6 investigate the influence of the composition of composite foaming agent and foam stabilizer on foaming performance. In Examples 1-4 of the present application, the foam half-life can reach 2180-2220min, the foam decays slowly, and the stability is high. The stability of Comparative Examples 3-4 is significantly lower than that of Example 4, and Comparative Example 3 is the lowest. In Comparative Example 4, adding lauryl alcohol and xanthan gum can significantly improve the stability of foam, but it is still far lower than that of Example 4, indicating that lauryl alcohol, xanthan gum and nanoparticles have a synergistic foam-stabilizing effect. The foaming amount of Comparative Examples 5-6 is significantly lower than that of Example 4, and the stability is also reduced to a certain extent, and the foaming volume of Example 5 is small, indicating that when simply using animal protein as a foaming agent, the foaming amount and stability are not enough. After adding sodium dodecylbenzenesulfonate, the foaming performance is improved, but it is still far lower than that of Example 4, indicating that the composite system of the composite foaming agent can significantly improve the foaming amount and also has certain foam-stabilizing performance.

[0075] Figure 1 The water loss rate curve of the materials of Examples 1-4 and Comparative Examples 1-2 is shown in FIG. Figure 1 It can be seen that the water loss rate of the material increases rapidly in the early stage, and tends to be stable in the later stage as the moisture in the material decreases. The water retention performance of Comparative Examples 1-4 is significantly better than that of Comparative Examples 1 and 2, indicating that the network system of the present application greatly increases the water retention performance of the material and helps to increase the fire extinguishing performance of the material.

[0076] Figure 3 The applied pressure-pressure difference curve shows that when the same pressure is applied, the pressure difference of Examples 1-4, that is, the pressure tolerance of the material, is significantly better than that of Comparative Example 1 and Comparative Example 2, indicating that the system composed of sodium carboxymethyl cellulose-fly ash-based gel material and foam in the present application can achieve excellent air leakage plugging effect.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and are not limiting. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A coal mine grouting and plugging material, consisting of three parts: material A, material B, and material C, characterized in that: The weight ratio of the materials A, B, and C is 1:1:1; the composition of the material A, in parts by weight, includes: 5-8 parts of fly ash, 4-6 parts of composite filler, 1-1.5 parts of sodium silicate, 5-6 parts of cross-linking agent, and 5-6 parts of water; the composition of the material B, in parts by weight, includes: 1-1.2 parts of composite foaming agent, 0.5-0.8 parts of foam stabilizer, and 40-48 parts of water; the composition of the material C, in parts by weight, includes: 1.5-2 parts of sodium carboxymethyl cellulose and 100 parts of water; The cross-linking agent is a slow-release cross-linking agent, which is prepared by the following steps: Dissolve soluble starch in water, heat to 50°C, add acrylic acid, ammonium persulfate and aluminum citrate and stir evenly, finally add acrylamide, N,N-methylenebisacrylamide and montmorillonite, stir and react for 1 hour, let stand for 2 hours to obtain a gel product, grind and granulate with a grinder and sieve to obtain a slow-release crosslinking agent with a particle size of 0.1-0.5 mm; the weight ratio of the soluble starch, acrylic acid, acrylamide, aluminum citrate, montmorillonite, ammonium persulfate and N,N-methylenebisacrylamide is 10:5:5:8-10:2:0.01:0.01; The preparation method of the coal mine grouting and plugging air leakage material comprises the following steps: mixing and stirring the raw materials in material B uniformly, foaming the material A with a foaming device, mixing the foam and the slurry uniformly, and then uniformly stirring the mixture with material C, and transporting the mixture for grouting.

2. The coal mine grouting and air leakage plugging material according to claim 1, characterized in that: The composite filler is prepared by mixing expanded vermiculite and loess in a weight ratio of 2:

1.

3. The coal mine grouting and air leakage plugging material according to claim 2, characterized in that: The loess is loess from a mining area, which is dried and crushed, and sieved to obtain particles with a particle size of ≤0.5 mm.

4. The coal mine grouting and air leakage plugging material according to claim 1, characterized in that: The composite foaming agent is prepared by mixing an animal protein foaming agent, sodium dodecylbenzene sulfonate, sodium α-olefin sulfonate and sodium lauryl sulfate in a weight ratio of 20:1:1:

1.

5. The coal mine grouting and air leakage plugging material according to claim 1, characterized in that: The foam stabilizer is prepared by mixing lauryl alcohol, xanthan gum and nanoparticles in a weight ratio of 2.5:0.5:1-2.

6. The coal mine grouting and air leakage plugging material according to claim 5, characterized in that: The nanoparticles are a mixture of nano calcium carbonate and nano silicon dioxide in a weight ratio of 1:1-2.

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