Mining composite grouting reinforcement material and preparation method thereof

Abstract

The invention relates to a mining composite grouting reinforcement material and a preparation method thereof.The mining composite grouting reinforcement material comprises a component A and a component B. When the mining composite grouting reinforcement material is used, the volume ratio of the component A to the component B is 1: (0.95-1.05); the component A comprises the following raw materials in parts by weight: 40-70 parts of polyether polyol, 10-30 parts of a flame retardant, 25-40 parts of modified fly ash, 0.1-0.3 part of a catalyst and 0.1-0.3 part of an anti-settling dispersant; the component B comprises the following raw materials in parts by weight: 40-70 parts of isocyanate, 10-30 parts of a flame retardant, 25-40 parts of modified fly ash and 0.1-0.3 part of an anti-settling dispersant. The invention belongs to an environment-friendly mining reinforcing material, and the cheap and easily available fly ash is introduced into a polyurethane system in an organic and inorganic composite manner, so that the use proportion of organic raw materials is reduced, the product cost is reduced, and the comprehensive performance of the material is also improved.

Description

Technical Field

[0001] The present invention relates to the technical field of mine reinforcement materials, and particularly relates to a mine composite grouting reinforcement material and a preparation method thereof. Background Art

[0002] With the deepening of coal mine mining depth, complex geological conditions such as soft rock strata and fault fracture zones are often encountered during the excavation of surrounding rocks in deep roadway. Grouting reinforcement is commonly used in deep roadway tunneling and working face coal mining. Through the grouting equipment, the reinforcement material is injected into the cracks of the broken surrounding rock. After it undergoes a cross-linking curing reaction, the formed consolidated body cements the original loose and broken coal and rock mass into a dense network skeleton, improving the stability of the surrounding rock and the structural bearing capacity, avoiding accidents such as roof falls and rib spalling during the mining process, and ensuring the safe and efficient production of the coal mine.

[0003] Grouting reinforcement is one of the main means for controlling the surrounding rocks of deep roadways at present. The performance of the reinforcement material plays a decisive role in the reinforcement effect. Commonly used polyurethane-based organic reinforcement materials such as Marisal have disadvantages such as high cost, intense reaction heat release, poor flame retardant effect, and easy ignition of underground fires. With the implementation of the new safety standard AQ / T 1089-2020, the curing temperature of organic reinforcement materials is strictly limited within 100°C. Most products on the market sacrifice some mechanical properties to meet the requirements of the new safety standard for the curing temperature, and it is difficult to meet the actual use needs of coal mines. Some products are difficult to meet the requirements of the new safety standard for the curing temperature in order to improve the strength.

[0004] In the field of mine reinforcement, polyurethane-based organic materials are commonly used for double-fluid grouting reinforcement. The A component is generally polyether or polyester polyol, and the B component is generally isocyanate. In essence, a series of reactions occur between the hydroxyl group of the A component and the isocyanate group (-NCO) of the B component to form a block copolymer with alternating hard and soft segments containing urethane groups (-NHCOO-). However, this type of material has disadvantages such as high cost, intense reaction heat release, poor flame retardant effect, and easy ignition of fires.

[0005] Organic-inorganic composite grouting materials are a major development direction in the future. At present, silicate-modified polyurethane materials have been widely used in engineering practice. The A component is an aqueous solution of sodium silicate, and the B component is still isocyanate. After the A and B components are mixed, the CO2 generated by the reaction of isocyanate with water further reacts with the silicate to form a solidification reaction, introducing Si-O chain segments into the organic structure, and finally forming a three-dimensional structure interpenetrating network of an organic phase (polyurethane network) - an inorganic phase (inorganic silicate network). Although it has advantages such as low reaction temperature, good flame retardant performance, and adaptability to water-containing coal seams, the consolidated body of this type of material is brittle, has a high hardness, and has a weak adhesion to the coal seam, and it is difficult to ensure the reinforcement effect under special working conditions, and the actual use effect is still not ideal, and it still cannot completely replace pure organic polyurethane materials.

[0006] For the "A kind of mining fly ash / polyurethane grouting composite material and its preparation method" with the application number 202410349736.3, 20% of untreated fly ash is added to component A, and a prepolymer is introduced into component B to reduce the content of isocyanate groups (-NCO), so as to reduce the overall reaction temperature and improve the flame retardant performance. The compressive strength can reach 60 MPa. For the "Low-temperature mining coal rock mass reinforcement grouting material and its preparation method" with the application number 202410212007.3, diatomite is wet-modified with a silicone oil solution and then added to component A at a ratio of 10%. The curing temperature and compressive strength are also tested, and the compressive strength can also reach 60 MPa. However, both of these two patents only fill in a single component, and the total addition amount of inorganic substances is still relatively low, failing to fully exert the cost advantage and reinforcement performance of inorganic fillers. Moreover, the wet modification process also requires filtration and drying to obtain the product, and the process is relatively complex and the cost is relatively high. The present invention uses a dry process to surface-modify inorganic mineral powders and then introduce them into the polyurethane system to prepare a low-cost and high-performance mining composite grouting reinforcement material. Summary of the Invention

[0007] The present invention provides a mining composite grouting reinforcement material and its preparation method to solve one or several of the technical problems existing in the prior art.

[0008] The technical solution of the present invention to solve the above technical problems is as follows: A mining composite grouting reinforcement material includes component A and component B. When in use, the volume ratio of component A to component B is 1:(0.95 - 1.05);

[0009] Component A includes the following raw materials in parts by weight: 40 - 70 parts of polyether polyol, 10 - 30 parts of flame retardant, 25 - 40 parts of modified fly ash, 0.1 - 0.3 parts of catalyst, 0.1 - 0.3 parts of anti-settling dispersant;

[0010] Component B includes the following raw materials in parts by weight: 40 - 70 parts of isocyanate, 10 - 30 parts of flame retardant, 25 - 40 parts of modified fly ash, 0.1 - 0.3 parts of anti-settling dispersant.

[0011] The beneficial effects of the present invention are as follows: The mine-used composite grouting reinforcement material of the present invention introduces inexpensive and easily available inorganic fillers such as fly ash as reinforcing materials into the polyurethane system in an organic + inorganic composite manner, reducing the usage ratio of organic raw materials and lowering the product cost. The prepared product has a low curing temperature, good flame retardant effect, and excellent mechanical properties. The compressive strength is as high as 104 Mpa, far exceeding the requirements of the safety standard (greater than 40 MPa), significantly superior to similar products in the market. The tensile fracture elongation and compression strain are large, and the product has high toughness, being able to better adapt to the roadway environment with large mining disturbances. The advantages of the mine-used composite grouting reinforcement material of the present invention benefit from giving full play to the excellent properties of fly ash itself. Through appropriate modification means, the surface polarity of fly ash is made close to that of the polymer resin, improving the interfacial compatibility between the two, enabling fly ash to be better dispersed and filled in the resin matrix, and enhancing the reinforcement effect.

[0012] Filling and modifying polyurethane-based pure organic materials with inorganic minerals such as fly ash. On the one hand, the inorganic minerals themselves have strong chemical stability. After being introduced into the polyurethane system, the usage ratio of organic raw materials can be reduced, the heat release during the reaction can be reduced, and the curing temperature can be lowered. On the other hand, it can also form a synergistic effect with the resin matrix material as a reinforcing phase, playing a reinforcing role. However, the wetting and dispersibility of inorganic fillers in the resin matrix are poor, and the surface of the fillers must be modified to change their surface from hydrophilic and lipophobic to lipophilic and hydrophobic, improving the interfacial compatibility between the two, enabling the fillers to be better dispersed and filled in the resin matrix, and enhancing the reinforcement effect.

[0013] On the basis of the above technical solutions, the present invention can be further improved as follows.

[0014] Further, the hydroxyl value of the polyether polyol is 150 - 550 mgKOH / g, the functionality is 2 - 3, and the viscosity is 250 - 600 mPa·s / 25 °C.

[0015] Optionally, the hydroxyl value of the polyether polyol is 150 mgKOH / g, 230 mgKOH / g, 325 mgKOH / g, 420 mgKOH / g, 550 mgKOH / g, the functionality is 2 or 3, and the viscosity is 250 mPa·s / 25 °C, 300 mPa·s / 25 °C, 350 mPa·s / 25 °C, 450 mPa·s / 25 °C, 600 mPa·s / 25 °C.

[0016] The polyether polyol in component A of the present invention can be a polyol with a single hydroxyl value, a single viscosity value, and a single functionality, or a combination of two or more polyols with different hydroxyl values, viscosity values, and functionalities can be selected for compounding.

[0017] Further, the content of isocyanate groups in the isocyanate is 30% - 32%, and the viscosity is 150 - 450 mPa·s / 25 °C.

[0018] Optionally, the content of isocyanate groups in the isocyanate is 30%, 30.5%, 31%, 31.5%, 32%, and the viscosity is 150 mPa·s / 25°C, 200 mPa·s / 25°C, 250 mPa·s / 25°C, 300 mPa·s / 25°C, 350 mPa·s / 25°C, 400 mPa·s / 25°C, 450 mPa·s / 25°C.

[0019] The isocyanate of component B of the present invention can be an isocyanate with a single isocyanate group content and a single viscosity value, or two or more isocyanates with different isocyanate group contents and viscosity values can be selected for compounding.

[0020] Furthermore, the flame retardant includes one or more of tris(2-chloropropyl) phosphate, tris(2-chloroethyl) phosphate, triethyl phosphate, triphenyl phosphate, and tricresyl phosphate.

[0021] Furthermore, the catalyst is selected from one of dibutyltin dilaurate, lead octoate, stannous octoate, bismuth isooctoate, and zinc isooctoate.

[0022] Furthermore, the anti-settling dispersant is selected from one or more of polyethylene wax, castor oil derivatives, polyamide-modified alkyd resin, polyurethane-modified alkyd resin, copolymer of high molecular carboxylic acid and silicone, and modified polyurea thickener.

[0023] A preparation method of the above-mentioned mine composite grouting reinforcement material includes the following steps:

[0024] S1, pretreat the fly ash to obtain modified fly ash;

[0025] S2, sequentially add the raw materials of component A into the reaction kettle, fully stir and disperse them evenly under nitrogen protection, and maintain the vacuum degree for the first preset time; sequentially add the raw materials of component B into the reaction kettle, fully stir and disperse them evenly under nitrogen protection, and maintain the vacuum degree for the second preset time;

[0026] S3, mix the uniformly dispersed component A and component B according to a preset volume ratio to obtain the mine composite grouting reinforcement material.

[0027] The beneficial effects of the present invention are as follows: The preparation method of the mine composite grouting reinforcement material of the present invention has a simple process, the prepared product has a low curing temperature, good flame retardant effect, excellent mechanical properties, and high shear strength.

[0028] Further, in S1, the fly ash is pretreated, including separating the fly ash to D97 of 800 - 2500 mesh, placing the separated fly ash in a stirring mixer, heating and activating the fly ash under the first preset temperature condition for 30 min - 90 min, then slowly adding a surface modification solution, where the mass of the surface modification solution is 2.5 - 10% of the mass of the fly ash, and mixing the surface modification solution and the fly ash evenly under the second preset temperature condition to obtain modified fly ash. The first preset temperature is 110°C - 130°C, and the second preset temperature is 50°C - 70°C.

[0029] The beneficial effects of adopting the above further scheme are as follows: By separating and modifying the fly ash, the surface polarity of the fly ash is made close to that of the polymer resin, improving the interfacial compatibility between the two, enabling the fly ash to be better dispersed and filled in the resin matrix, and enhancing the reinforcement effect. By dry-modifying the fly ash, it has a wider industrial application. It is more suitable to use the dry process to surface-modify inorganic mineral powders, with relatively low cost and simpler process.

[0030] Further, the preparation process of the surface modification solution is to mix a surface modifier and ethanol according to a preset mass ratio, and then add an acetic acid solution to adjust the pH value to 4 - 6 to obtain the surface modification solution.

[0031] Further, the surface modifier includes at least one of silane coupling agent, aluminate coupling agent, titanate coupling agent, zirconium aluminate coupling agent, higher fatty acid and its salt, higher phosphate ester salt, higher amine salt, polyethylene glycol, polyacrylic acid, sodium polyacrylate, ammonium polyacrylate, polyacrylamide, and silicone oil. Description of the Drawings

[0032] Figure 1 It is a compression strain chart of the mine composite grouting reinforcement material in Example 3 of the present invention under different compressive stresses;

[0033] Figure 2 It is a tensile deformation chart of the mine composite grouting reinforcement material in Example 3 of the present invention under different tensile strengths. Detailed Embodiments

[0034] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0035] The technical solution of the present invention is described below by specific embodiments. It should be understood that the one or more steps mentioned in the present invention do not exclude the existence of other methods and steps before and after the combination step, or other methods and steps can be inserted between these explicitly mentioned steps. It should also be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Unless otherwise specified, the numbering of each method step is only for the purpose of identifying each method step, and does not limit the order of arrangement of each method or limit the scope of implementation of the present invention. The change or adjustment of the relative relationship thereof can also be regarded as the scope of implementation of the present invention without substantial changes in the technical content.

[0036] The sources of the raw materials and instruments used in the examples are not particularly limited and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0037] Example 1

[0038] A composite grouting reinforcement material for mining in this embodiment includes component A and component B, and the volume ratio of component A to component B is 1:1;

[0039] Component A includes the following raw materials in parts by weight: 55 parts of polyether polyol, 20 parts of flame retardant, 25 parts of modified fly ash, 0.1 parts of catalyst, and 0.2 parts of anti-settling dispersant;

[0040] Component B includes the following raw materials in parts by weight: 55 parts of isocyanate, 20 parts of flame retardant, 25 parts of modified fly ash, and 0.2 parts of anti-settling dispersant.

[0041] The polyether polyol is of model H305, purchased from Hongbaoli Group Co., Ltd. The isocyanate is polymethylene polyphenyl isocyanate (Huntsman 5005). The flame retardant is of model TCPP, purchased from Zhejiang Wansheng Co., Ltd. The catalyst is dibutyltin dilaurate (Evonik DABCO T-12). The anti-settling dispersant is DeuRheo 202P from Hemings.

[0042] A method for preparing the above-mentioned composite grouting reinforcement material for mining comprises the following steps:

[0043] S1, pre-treating fly ash to obtain modified fly ash; the fly ash is selected from Guoneng Shouguang Power Generation Co., Ltd.;

[0044] S2, adding each raw material of component A into the reactor in sequence, stirring them thoroughly for 30 to 90 minutes under nitrogen protection to make them evenly dispersed, and maintaining the vacuum degree for 10 to 30 minutes; adding each raw material of component B into the reactor in sequence, stirring them thoroughly for 30 to 90 minutes under nitrogen protection to make them evenly dispersed, and maintaining the vacuum degree for 10 to 30 minutes;

[0045] S3. Mix the evenly dispersed Component A and Component B in a volume ratio of 1:1, stir for about 30 s with an electric stirrer (600 rpm / min), and pour the mixture into the corresponding mold after uniform mixing to obtain the test block to be tested.

[0046] In S1, the fly ash is pretreated, including separating the fly ash to D97 of 800 - 2500 mesh, placing the separated fly ash in a stirring mixer, heating and activating the fly ash at 110 °C for 1 h, then slowly adding a surface modification solution, where the mass of the surface modification solution is 5% of the mass of the fly ash, and mixing the surface modification solution and the fly ash evenly at 60 °C to obtain modified fly ash.

[0047] Furthermore, the preparation process of the surface modification solution is that the surface modification solution is prepared by mixing silane coupling agent KH-560, titanate coupling agent NDZ-201 and ethanol solution in a mass ratio of 1:1:8, and then adding a small amount of acetic acid solution to adjust the pH to 4 - 6.

[0048] The titanate coupling agent NDZ-201 contains a monoalkoxy group and three groups that act with the organic base material. The silane coupling agent KH-560 has three alkoxy groups and one glycidyl ether oxypropyl active functional group. The alkoxy group undergoes a chemical reaction with the hydroxyl group on the fly ash surface, adsorbs on the surface of the inorganic particles, and can also undergo a ring-opening reaction with the epoxy group in the glycidyl ether oxypropyl at the end of the silane. The two coupling agents produce a synergistic effect, forming a firm organic coating layer on the particle surface, improving the unstable spatial structure when using only titanate, and also solving the problem of fewer groups that form chemical bonds or physical entanglements with organic polymer molecules in the system when using only silane. The compounding of the two coupling agents enhances the binding force with the organic polymer matrix and improves the dispersibility and interfacial compatibility of the inorganic filler.

[0049] Example 2

[0050] A kind of mine-used composite grouting reinforcement material in this example includes Component A and Component B, and the volume ratio of Component A to Component B is 1:1;

[0051] Component A includes the following raw materials in parts by weight: 50 parts of polyether polyol, 20 parts of flame retardant, 30 parts of modified fly ash, 0.1 part of catalyst, 0.2 part of anti-settling dispersant;

[0052] Component B includes the following raw materials in parts by weight: 50 parts of isocyanate, 20 parts of flame retardant, 30 parts of modified fly ash, 0.2 part of anti-settling dispersant.

[0053] The rest is the same as in Example 1.

[0054] Example 3

[0055] A kind of mine-used composite grouting reinforcement material in this embodiment comprises component A and component B, and the volume ratio of component A to component B is 1:1;

[0056] Component A comprises the following raw materials in parts by weight: 45 parts of polyether polyol, 20 parts of flame retardant, 35 parts of modified fly ash, 0.1 part of catalyst, 0.2 part of anti-settling dispersant;

[0057] Component B comprises the following raw materials in parts by weight: 45 parts of isocyanate, 20 parts of flame retardant, 35 parts of modified fly ash, 0.2 part of anti-settling dispersant.

[0058] The rest is the same as that in Embodiment 1.

[0059] Embodiment 4

[0060] A kind of mine-used composite grouting reinforcement material in this embodiment comprises component A and component B, and the volume ratio of component A to component B is 1:1;

[0061] Component A comprises the following raw materials in parts by weight: 40 parts of polyether polyol, 20 parts of flame retardant, 40 parts of modified fly ash, 0.1 part of catalyst, 0.2 part of anti-settling dispersant;

[0062] Component B comprises the following raw materials in parts by weight: 40 parts of isocyanate, 20 parts of flame retardant, 40 parts of modified fly ash, 0.2 part of anti-settling dispersant.

[0063] The rest is the same as that in Embodiment 1.

[0064] Comparative Example 1

[0065] A kind of mine-used composite grouting reinforcement material in this embodiment comprises component A and component B, and the volume ratio of component A to component B is 1:1;

[0066] Component A comprises the following raw materials in parts by weight: 80 parts of polyether polyol, 20 parts of flame retardant, 0.1 part of catalyst;

[0067] Component B comprises the following raw materials in parts by weight: 80 parts of isocyanate, 20 parts of flame retardant.

[0068] The rest is the same as that in Embodiment 1.

[0069] Comparative Example 2

[0070] A kind of mine-used composite grouting reinforcement material in this embodiment comprises component A and component B, and the volume ratio of component A to component B is 1:1;

[0071] Component A comprises the following raw materials in parts by weight: 65 parts of polyether polyol, 35 parts of modified fly ash, 0.1 part of catalyst, 0.2 part of anti-settling dispersant;

[0072] Component B comprises the following raw materials in parts by weight: 65 parts of isocyanate and 35 parts of flame retardant.

[0073] The rest is the same as in Example 1.

[0074] Comparative Example 3

[0075] A kind of mine-used composite grouting reinforcement material in this example comprises Component A and Component B, and the volume ratio of Component A to Component B is 1:1;

[0076] Component A comprises the following raw materials in parts by weight: 65 parts of polyether polyol, 35 parts of flame retardant, and 0.1 part of catalyst;

[0077] Component B comprises the following raw materials in parts by weight: 65 parts of isocyanate and 35 parts of modified fly ash.

[0078] The rest is the same as in Example 1.

[0079] Now, the properties of the mine-used composite grouting reinforcement materials prepared in Examples 1 to 4 and Comparative Examples 1 to 3 are tested.

[0080] The test method adopts the industrial safety standard AQ / T 1089-2020, and tests the curing temperature of Component A and Component B, as well as the compressive strength, tensile strength and oxygen index of the consolidated body.

[0081] The test results are shown in Table 1, Figure 1 and Figure 2 as follows:

[0082] Table 1 Performance test table of mine-used composite grouting reinforcement materials

[0083] Curing temperature / °C Compressive strength / Mpa Tensile strength / Mpa Oxygen index / % Example 1 99.6℃ 79.7 Mpa 14.8 Mpa 28.0％ Example 2 96.0℃ 90.0 Mpa 15.9 Mpa 28.2％ Example 3 94.5℃ 104.2 Mpa 16.6 Mpa 28.7％ Example 4 92.9℃ 107.9 Mpa 16.0 Mpa 29.0％ Comparative example 1 130℃ 46.8 Mpa 13.1 Mpa 25.5％ Comparative example 2 115℃ 69.0 Mpa 13.6 Mpa 27％ Comparative example 3 119℃ 63.5 Mpa 14.0 Mpa 26.8％

[0084] As can be seen from Table 1, from Example 1 to Example 4, with the increase in the parts by weight of modified fly ash in Component A and Component B, the content of organic matter decreases accordingly, the curing temperature of the mine-used composite grouting reinforcement material gradually decreases, and the compressive strength, tensile strength and oxygen index generally show an increasing trend, indicating that the modified fly ash can be well wetted and dispersed in the organic polymer matrix, improving the mechanical properties and flame retardant properties of the composite material. After the parts by weight of the modified fly ash in Example 4 increase to 40 parts, the overall performance is not much different from that of Example 3. However, considering that a high solid content will make the storage stability of the material poor and a too high slurry viscosity is also not conducive to grouting construction, considering the product economy and construction convenience comprehensively, the optimal choice can be the parts by weight of the modified fly ash in Example 3. It is equivalent to using a certain amount of solid waste fly ash as a functional filler to partially replace the organic matter in Component A and Component B at low cost.

[0085] In Example 3, when the overall filling amount of modified fly ash is 35%, the curing temperature is 94.5°C, the compressive strength reaches 104.2 MPa, and the tensile strength is 16.6 MPa. As Figure 1 shown, the maximum compressive strength deformation is 55%, and the oxygen index is 28.7%. This shows that the modified fly ash has a beneficial effect of enhancing and toughening in the polyurethane resin. At the same time, since fly ash is a product formed after the high-temperature combustion of pulverized coal in the furnace, it itself has excellent properties such as incombustibility, high temperature resistance, and low thermal conductivity. After being compounded with organic polymers, the flame retardant performance is improved. This product solves the pain points and problems in the field of current mine reinforcement materials, and at the same time realizes the high-value resource utilization of coal-based solid waste fly ash.

[0086] In Comparative Example 1, no modified fly ash is added to both Component A and Component B. The curing temperature reaches 130°C, and the oxygen index is also lower than 28%, which does not meet the requirements of the safety standard, and the safety is poor. Especially when there is a large volume of slurry aggregation at the grouting position, the large amount of reaction heat released during curing is difficult to dissipate, which may cause the spontaneous combustion of the surrounding coal seams and trigger a fire accident. In Comparative Example 2 and Comparative Example 3, modified fly ash is only added to a single component, and at the same time, the isocyanate index (n (-NCO) :n (-OH) ) is kept the same to make it comparable. It can be seen from the results that the curing temperature is significantly reduced, and the mechanical properties and flame retardant properties are improved to a certain extent, but still cannot fully meet the requirements of the safety standard, and the compressive strength is still relatively low, and it cannot well adapt to complex geological conditions such as large-deformation soft coal and rock roadways. Moreover, the filling of a single component will cause a large difference in the viscosities of Component A and Component B, and it is difficult to accurately control the double-liquid ratio during grouting, affecting the grouting effect.

[0087] The above examples only describe the specific implementation manners of the present invention, and do not limit the scope of the present invention. Those skilled in the art can make various modifications and changes based on the prior art. Without departing from the design spirit of the present invention, various variations and improvements made by ordinary engineering and technical personnel in the art to the technical solution of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A composite grouting reinforcement material for mining, characterized in that: It comprises component A and component B, wherein the volume ratio of component A to component B is 1:(0.95-1.05); Component A includes the following raw materials in parts by weight: 40-70 parts of polyether polyol, 10-30 parts of flame retardant, 25-40 parts of modified fly ash, 0.1-0.3 parts of catalyst, and 0.1-0.3 parts of anti-settling dispersant; Component B comprises the following raw materials in parts by weight: 40-70 parts of isocyanate, 10-30 parts of flame retardant, 25-40 parts of modified fly ash, and 0.1-0.3 parts of anti-settling dispersant.

2. A composite grouting reinforcement material for mining according to claim 1, characterized in that: The polyether polyol has a hydroxyl value of 150 to 550 mgKOH / g, a functionality of 2 to 3, and a viscosity of 250 to 600 mPa·s / 25°C.

3. A composite grouting reinforcement material for mining according to claim 1, characterized in that: The content of isocyanate in isocyanate is 30% to 32%, and the viscosity is 150 to 450 mPa·s / 25°C.

4. A composite grouting reinforcement material for mining according to claim 1, characterized in that: The flame retardant includes one or more of tris(2-chloropropyl) phosphate, tris(2-chloroethyl) phosphate, triethyl phosphate, triphenyl phosphate, and tricresyl phosphate.

5. A composite grouting reinforcement material for mining according to claim 1, characterized in that: The catalyst is selected from one of dibutyltin dilaurate, lead octoate, stannous octoate, bismuth isooctanoate and zinc isooctanoate.

6. A composite grouting reinforcement material for mining according to claim 1, characterized in that: The anti-settling dispersant is selected from one or more of polyethylene wax, castor oil derivatives, polyamide modified alkyd resin, polyurethane modified alkyd resin, polymer carboxylic acid and silicone copolymer, and modified polyurea thickener.

7. A method for preparing the composite grouting reinforcement material for mining according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, pretreating fly ash to obtain modified fly ash; S2, adding each raw material of component A to the reactor in sequence, stirring and dispersing them evenly under the protection of nitrogen, and maintaining the vacuum degree for a first preset time; adding each raw material of component B to the reactor in sequence, stirring and dispersing them evenly under the protection of nitrogen, and maintaining the vacuum degree for a second preset time; S3, mixing the evenly dispersed component A and component B according to a preset volume ratio to obtain the composite grouting reinforcement material for mining.

8. The preparation method according to claim 7, characterized in that: In S1, the fly ash is pretreated, including sorting the fly ash to a D97 of 800-2500 mesh, placing the sorted fly ash in a stirring mixer, heating and activating the fly ash under a first preset temperature condition, slowly adding a surface modification solution, the mass of the surface modification solution is 4-6% of the mass of the fly ash, and uniformly mixing the surface modification solution and the fly ash under a second preset temperature condition to obtain modified fly ash.

9. The preparation method according to claim 8, characterized in that: The preparation process of the surface modification solution is to mix the surface modifier and ethanol according to a preset mass ratio, and then add acetic acid solution to adjust the pH value to 4-6 to obtain the surface modification solution.

10. The preparation method according to claim 9, characterized in that: The surface modifier includes at least one of silane coupling agent, aluminate coupling agent, titanate coupling agent, zirconium aluminate coupling agent, higher fatty acids and their salts, higher phosphate salts, higher amine salts, polyethylene glycol, polyacrylic acid, sodium polyacrylate, ammonium polyacrylate, polyacrylamide, and silicone oil.

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