Novel low-carbon normal-temperature grouting material for mine as well as preparation method and application of novel low-carbon normal-temperature grouting material

Abstract

The invention provides a novel low-carbon normal-temperature grouting material for mining, which is a two-component system composed of sodium silicate, inorganic acid, nano aluminum hydroxide and the like, and realizes accurate regulation and control of gelation time by optimizing a formula. The material has excellent permeability, high compressive strength, strong interface bonding force and good flame retardant property, and is suitable for coal mine goaf reinforcement and fracture treatment. Compared with a traditional material, the initial setting time is adjustable within 1-50 minutes, the final setting time is shorter than 80 minutes, the construction period is remarkably shortened, slurry loss is reduced, and the early strength is improved; the volume shrinkage rate is lower than 4%, and the gas leakage risk is effectively reduced. Industrial field tests show that the grouting material has remarkable safety and economic benefits.

Description

Technical Field

[0001] The present invention belongs to the field of coal mine safety engineering, and specifically relates to a grouting material suitable for grouting reinforcement and sealing of micro-cracks in coal rock masses in coal mines. The grouting material has the characteristics of shortening the construction period, reducing slurry loss, and improving early strength. Background Art

[0002] Grouting sealing technology has become a key solution to the problems of high drilling resistance, drill sticking, and low slag return efficiency caused by geological structures during drilling in complex formations underground in coal mines. This technology injects a specific slurry into the broken surrounding rock of the tunnel under high pressure, causing the loose rock mass to cement into an integral structure, essentially optimizing the physical and mechanical properties of the surrounding rock (such as compressive strength, deformation modulus, etc.), enabling it to independently bear external loads. Compared with traditional support systems, grouting technology has two advantages: first, it significantly improves the self-stability of the surrounding rock by reconstructing the rock microstructure and suppresses the rheology of deep soft rock; second, it forms a high-strength reinforcement layer inside the surrounding rock, providing an effective stress transfer medium for anchor support. The core technology lies in the performance control of grouting materials. The slurry must have Newtonian fluid properties (viscosity <50mPa·s) to achieve long-distance diffusion and penetration. The gel time must be controlled in the range of 5-30 minutes to adapt to dynamic crack sealing. At the same time, the 2-hour compressive strength must reach above 5MPa to ensure that the grouting area quickly forms a load-bearing structure, guaranteeing the continuity of mining operations and the stability of the tunnel.

[0003] Traditional sealing materials are mainly divided into polyurethane-based organic materials and cement-based inorganic materials. Polyurethane materials have the characteristics of low viscosity, rapid gelation, and good ductility and flexibility. They can be injected into fine cracks of a few microns and achieve rock bonding. However, they are expensive, dense, have poor durability, low strength, and pose certain toxicity and heat release risks, which may cause safety accidents such as coal dust combustion. Cement materials are known for their advantages such as high early strength, good chemical inertness, and strong wear resistance. However, they have defects such as poor thixotropy, unstable performance, long setting time, insufficient permeability, unadjustable setting time, and slow improvement in early mechanical properties.

[0004] Field research and technical analysis at multiple mining sites revealed that drilling and grouting in complex underground coal mine formations places specific demands on material performance: First, the grouting reinforcement material must have the shortest possible setting time to shorten the construction period; second, both early and late strength must be stable to meet the demands of repeated drilling; and third, the reaction heat release must be as low as possible to maintain the material's long-term strength stability and reduce safety risks during underground operations. The inherent flaws of traditional polyurethane and cement materials make it difficult to meet the comprehensive performance requirements of the complex working conditions in underground coal mines.

[0005] Traditional sealing materials have their own shortcomings. The setting time of cement and clay materials is difficult to control accurately, and it is difficult to inject them into fine cracks. Although polyurethane and its modified materials, epoxy resin and other materials have good performance, they are expensive, cure quickly and generate a lot of heat in a short time, which makes them more risky to use in coal mines. In view of this, in order to solve the problems of poor permeability of existing grouting reinforcement materials, easy agglomeration and poor dispersion of nano-reinforcements, unadjustable grouting setting time, low compressive strength, weak interface bonding, etc., the present invention has developed a new type of low-carbon room-temperature grouting material for inorganic mining. After formula optimization, it has the advantages of precise and adjustable setting time and good flame retardant properties. It can effectively penetrate fine cracks, has a low volume shrinkage rate, and significantly reduces the risk of disasters underground while ensuring the reinforcement strength, providing a safer and more economical solution for tunnel repair under complex geological conditions. Summary of the Invention

[0006] The purpose of the present invention is to provide a new type of low-carbon room-temperature grouting material for mining and its application in coal mines. The grouting material is designed with a two-component system of sodium silicate, inorganic acid and nano-aluminum hydroxide. By optimizing the formula, precise control of the gel time is achieved. The grouting reinforcement material has good permeability, high compressive strength and other mechanical properties, low volume shrinkage and good flame retardant properties, providing a safe and controllable engineering solution for underground tunnel reinforcement and goaf area fissure management.

[0007] The present invention provides a new low-carbon room-temperature grouting material for mining, comprising material A and material B with a mass ratio of 4:1:

[0008] Material A includes the following raw materials in parts by weight: 20-45 parts of sodium silicate, 3-8 parts of modified aluminum hydroxide, 3-10 parts of nano silicon powder, 1-3 parts of calcium stearate, 1-5 parts of calcium gluconate, 1-3 parts of polycarboxylate water reducer, 1-10 parts of auxiliary agent, and the balance is water.

[0009] Material B comprises the following raw materials in parts by weight: 5-15 parts of boric acid, 1-3 parts of citric acid, 0.5-1 part of surfactant, and the balance of water.

[0010] Preferably, the modified aluminum hydroxide is first modified with KH570 and then modified with mercapto polyethylene glycol. Preferably, the preparation method of the modified aluminum hydroxide comprises: stirring aluminum hydroxide powder and KH570 at a mass ratio of 100:5-10 for 30-60 minutes; then adding 3-5wt% mercapto polyethylene glycol to the aluminum hydroxide, continuing stirring and mixing under ultraviolet light for 30-60 minutes, and drying to obtain the modified aluminum hydroxide.

[0011] Preferably, the UV light intensity is 10-30 mW / cm 2 The stirring and mixing speed is 300-600r / min.

[0012] Preferably, the drying temperature is 80-100° C., and the drying time is 40-80 min.

[0013] Preferably, the average particle size of the nano-silicon powder is 50-150 nm, and the average particle size of the modified aluminum hydroxide is 200-500 nm.

[0014] Preferably, the mercapto polyethylene glycol is monomercapto polyethylene glycol and / or dimercapto polyethylene glycol, and the molecular weight of the polyethylene glycol is PEG500-PEG5000.

[0015] Preferably, the surfactant of the material B is at least one of sodium dodecylbenzenesulfonate, polysorbate 80, sodium lauryl sulfate, and lignin sulfonate.

[0016] Preferably, the auxiliary agent of the material A includes at least one of a defoaming agent and a coupling agent, the defoaming agent is 0.5-5 parts, and the coupling agent is 1-5 parts.

[0017] Preferably, the defoaming agent is at least one of polydimethylsiloxane and tributyl phosphate, and the coupling agent is at least one of a silane coupling agent and an aluminate coupling agent.

[0018] The modulus of the sodium silicate is 1.5 to 2.5.

[0019] The present invention utilizes the trimethoxysilyl group in the KH570 molecule to react with the hydroxyl group on the surface of aluminum hydroxide to form a strong silicon-oxygen bond, thereby connecting KH570 to the aluminum hydroxide surface. Under ultraviolet light irradiation, the thiol group in the mercaptopolyethylene glycol reacts with the methacryloyloxy double bond in the KH570 molecule, allowing the polyethylene glycol to connect to the aluminum hydroxide surface and enhance the hydrophilicity. Through a step-by-step reaction, KH570 and aluminum hydroxide are first fully bonded, and then the mercaptopolyethylene glycol is introduced. This helps to improve the uniformity of the modifier's coverage and the degree of reaction on the aluminum hydroxide surface, thereby more effectively improving the dispersibility of nano-aluminum hydroxide in aqueous systems.

[0020] After mixing material A and material B, the pH value of the present invention rapidly decreases. The borate ions generated by boric acid hydrolysis react with the silicate ions in the sodium silicate to form a borosilicate gel with a three-dimensional network structure. The sodium silicate reacts with citric acid to increase the degree of crosslinking between the silicate ions, making the gel structure denser. The added modified aluminum hydroxide and nano-silicon powder act as filler and reinforcement phases, increasing the strength and rigidity of the gel and reducing volume shrinkage. Furthermore, they neutralize residual acidic substances, preventing acidic substances from corroding the surrounding environment and materials, further improving the performance and stability of the grouting material.

[0021] The calcium stearate and calcium gluconate used in the present invention are both organic calcium salt retarders and have a certain degree of surface activity. They mainly play the following two roles in grouting materials: first, they are adsorbed on the surface of silicate particles to achieve a retarding effect; second, they form a water film layer by combining with hydrogen bonds in water molecules through hydrophilic groups, which wraps around the surface of cement particles, hindering the development of cement hydration and thus achieving a retarding effect. Calcium stearate is adsorbed on the surface of reactants or products through its hydrophobic long-chain fatty acid groups to form an isolation film, hindering the contact of reactants, while improving the dispersibility of reactant particles and preventing them from aggregating too quickly; calcium gluconate generates a stable complex through coordination reaction between gluconate ions and silicate ions, etc., reducing its activity, and hydrolyzing to produce acidic substances to reduce the pH value of the system, inhibiting the reaction between alkaline substances and acidic substances. The two synergistically control the cross-linking reaction rate of sodium silicate and material B in coal mine grouting materials.

[0022] The nano-silicon powder and nano-aluminum hydroxide used in the present invention can shorten the setting time of cement curing agents, reduce the time interval between initial setting and final setting, significantly improve the compressive strength and other mechanical properties of the filling material, and steadily increase the later strength, while having good flame retardant properties; in addition, the silicon powder and nano-aluminum hydroxide have different particle sizes. By utilizing their particle size difference, it is beneficial for the grouting material to enter the tiny gaps, making the slurry structure more dense. In addition, the average particle size of the nano-silicon powder of the present invention is 50-150nm, and the average particle size of the modified aluminum hydroxide is 200-500nm. It is further preferred that the average particle size of the nano-silicon powder is 50-100nm, and the average particle size of the modified aluminum hydroxide is 300-400nm.

[0023] Preferably, the polycarboxylate water-reducing agent used in the present invention has a higher initial dispersibility for the grouting material than other types, such as naphthalene-based water-reducing agents, and can improve the fluidity of the grouting material and prevent water loss and secondary pollution. In addition, the polycarboxylate water-reducing agent can also improve the surface tension, making the surface tension lower and the permeability stronger, thereby improving the durability of the grouting material and having almost no inhibitory effect on its gel curing.

[0024] The present invention also provides a method for preparing a new low-carbon room-temperature grouting material for mining, which specifically comprises the following steps:

[0025] S1: Weigh the raw materials in material A according to the stoichiometric ratio, mix them evenly, and stir them at a water-cement ratio of 0.3 to 0.5:1 to obtain slurry A;

[0026] S2: Weigh the raw materials in material B according to the stoichiometric ratio, mix the raw materials evenly, and stir them according to a water-cement ratio of 0.3 to 0.5:1 to obtain material B slurry.

[0027] The present invention also provides an application of a new low-carbon room-temperature grouting material for mining in coal mines, comprising the following steps: using a grouting pump to suck slurry A and slurry B into a mixing pipe, and then injecting them into a grouting hole drilled in advance.

[0028] The advantages or beneficial effects of the novel low-carbon room-temperature grouting material for mining of the present invention include at least:

[0029] The grouting material of the present invention possesses excellent permeability, capable of penetrating deeply into micropores and cracks in coal mine rocks, a capability difficult to achieve with conventional suspension-based grouting materials. This grouting material not only exhibits good permeability but also possesses high mechanical strength, including compressive strength, excellent flame retardancy, and low volume shrinkage, effectively reducing the risk of gas leakage. This provides a safe and controllable engineering solution for the reinforcement of underground coal mine tunnels and the management of cracks in goaf areas. DETAILED DESCRIPTION

[0030] To more clearly illustrate the objectives, technical solutions, and advantages of the present invention, the technical solutions of the present invention will be described in detail below through specific embodiments. It should be noted that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention. The actual scope of protection of the present invention shall be based on the definition of the claims.

[0031] Unless otherwise specified, the materials and reagents used in the following examples and comparative examples are commercially available. The amounts of the components in the following examples are 1 g per part by weight or per portion unless otherwise specified.

[0032] 1. Preparation of modified aluminum hydroxide.

[0033] 1. Modified aluminum hydroxide 1#, the preparation method comprises: mixing aluminum hydroxide powder with an average particle size of 200nm and KH570 at a mass ratio of 100:5 for 30 minutes; then adding 3wt% mercapto polyethylene glycol to the aluminum hydroxide powder, and 2 Under the above conditions, stirring and mixing were continued for 30 min, and dried at 80° C. for 50 min to obtain modified aluminum hydroxide 1#.

[0034] 2. Modified aluminum hydroxide 2#, the preparation method includes: mixing aluminum hydroxide powder with an average particle size of 300nm and KH570 at a mass ratio of 100:8 for 40 minutes; then adding 5wt% mercapto polyethylene glycol to the aluminum hydroxide powder, and 2 Under the above conditions, stirring and mixing were continued for 30 min, and dried at 90° C. for 40 min to obtain modified aluminum hydroxide 2#.

[0035] 3. Modified aluminum hydroxide 3#, the preparation method includes: the same as modified aluminum hydroxide 2#, the difference is that the average particle size of the aluminum hydroxide powder is 400nm.

[0036] 4. Modified aluminum hydroxide 4#, the preparation method includes: the same as modified aluminum hydroxide 2#, the difference is that the average particle size of the aluminum hydroxide powder is 500nm.

[0037] 5. Modified aluminum hydroxide 5#, the preparation method includes: mixing aluminum hydroxide powder with an average particle size of 300nm and KH570 at a mass ratio of 100:8 for 40 minutes, and 2 Under the above conditions, stirring and mixing were continued for 30 min, and dried at 90° C. for 40 min to obtain modified aluminum hydroxide 5#.

[0038] 6. Modified aluminum hydroxide 6#, the preparation method comprises: mixing aluminum hydroxide powder with an average particle size of 300nm and mercapto polyethylene glycol at a mass ratio of 100:5 for 40 minutes, and 2 Under the above conditions, stirring and mixing were continued for 30 min, and dried at 90° C. for 40 min to obtain modified aluminum hydroxide 6#.

[0039] 2. Prepare new low-carbon room-temperature grouting materials for mining.

[0040] The present invention relates to a method for preparing a new low-carbon room-temperature grouting material for mining, comprising material A and material B with a mass ratio of 4:1, and specifically comprising the following steps:

[0041] S1: Preparation method of material A: According to the composition and content of material A in Table 1, use a high-speed mixer, mix at 800 r / min for 5 minutes, and stir according to a water-cement ratio of 0.4:1 to obtain material A slurry.

[0042] S2: Preparation method of material B: According to the composition and content of material B in Table 1, use a high-speed mixer, mix at 800 r / min for 5 minutes, and stir according to a water-cement ratio of 0.4:1 to obtain material B slurry.

[0043] Table 1: The mass parts (g) of each component in Examples 1-7 are as follows.

[0044]

[0045]

[0046] Table 2: The mass parts (g) of each component in Comparative Examples 1-7 are as follows.

[0047]

[0048] Comparative Example 8: The difference from Example 2 is that the nano-aluminum hydroxide is not modified, and other conditions are the same as those in Example 2.

[0049] 3. Performance evaluation:

[0050] The application of the grouting materials prepared in the embodiment and the comparative example in a coal mine comprises the following steps: respectively mixing material A and material B into material A slurry and material B slurry according to a water-material ratio of 0.4, and injecting the slurry A and slurry B into the grouting holes drilled in advance by using a grouting pump.

[0051] 1. Stability and liquidity analysis

[0052] 50g of each of the slurries A obtained in the Examples and Comparative Examples were stirred and mixed with 150g of water. The slurry stability was measured using the graduated cylinder standing method to observe whether there was precipitation or other phenomena, thereby characterizing the stability of the mixed slurry. The test results showed that after standing for 5 minutes, there was almost no precipitation in Examples 1-7 and Comparative Examples 1-5, slight precipitation occurred in the mixed slurries of Comparative Examples 6-7, and significant precipitation occurred in the mixed slurry of Comparative Example 8.

[0053] The slurry fluidity was measured using the standard GBT8077-2000. The mixed slurries A and B in the examples and comparative examples showed no significant loss of fluidity within 30 minutes, demonstrating excellent and stable slurry fluidity. From the perspective of construction injectability, good fluidity helps the slurry flow smoothly, fill, and penetrate into every corner and tiny gap in the construction area during the grouting process, improving grouting efficiency and quality and ensuring smooth construction.

[0054] 2. Performance test of grouting materials

[0055] The compressive strength, tensile strength, shear strength, and bond strength of the grouting material were tested according to the AQ / T 1089-2020 standard. The initial and final setting times of the grouting material were tested in accordance with the "Standard for Test Methods for Properties of Ordinary Concrete Mixtures" (GB / T50080-2016). The volume shrinkage was tested in accordance with GB / T 13477.19-2019, "Test Methods for Building Sealing Materials." The test results are shown in Table 3.

[0056] Table 3 Grouting material properties of different embodiments and control examples

[0057]

[0058] According to the data in Performance Test Table 3, the grouting material prepared by the present invention has high mechanical strength for coal mine filling, and the compressive strength, tensile strength, shear strength and bonding strength are respectively greater than 40Mpa, 5.5MPa, 16MPa and 3.5MPa, which can significantly improve the overall safety of soft and broken coal rock formations. In addition, the initial setting time is less than 50min, the final setting time is less than 80min, and the time interval between initial setting and final setting is short, which significantly shortens the construction period, enhances the grouting effect, reduces slurry loss and improves early strength, and reduces monitoring waiting time and other advantages. The volume shrinkage rate of the grouting material of the present invention is less than 4%, and the volume change during the curing process is small, indicating that the grouting material can fill the pores and cracks of the coal rock mass more tightly, reduce the pores caused by material shrinkage, thereby reducing the risk of gas leakage and avoiding geological disasters and safety hazards. At the same time, the aluminum hydroxide contained in the grouting material has good flame retardancy, and all raw materials are inorganic materials, which further enhances the flame retardancy of the grouting material.

[0059] From the comparison of Example 4-5 with Examples 2 and 6-7, it can be seen that the preferred combination is one in which the average particle size of the nano-silicon powder is 50-100 nm and the average particle size of the modified aluminum hydroxide is 300-400 nm. The silicon powder and the nano-aluminum hydroxide have different particle sizes. The difference in particle size is utilized to facilitate the grouting material to enter the fine gaps, making the slurry structure denser, significantly improving the mechanical strength of the coal mine filling, and reducing the volume shrinkage rate and solidification time.

[0060] Comparing the results of Example 2 with Comparative Examples 1-2 reveals that, due to the omission of boric acid in Comparative Example 1, a three-dimensional borosilicate gel network cannot be formed. This results in a slower setting speed of the grouting material, a significant decrease in mechanical strength, and a significant increase in volume shrinkage. Furthermore, due to the omission of nano-silicon powder in Comparative Example 2, the mechanical strength and setting time interval of the grouting material also decrease significantly.

[0061] Comparing Example 2 with Comparative Examples 3-4, it was found that using only calcium stearate or calcium gluconate as a retarder had little effect on the mechanical strength and volume shrinkage of the coal mine filling, but significantly prolonged the time interval between initial and final setting, which increased monitoring waiting time and made it difficult to meet the construction requirements of rapid filling and curing. Therefore, the synergistic effect of calcium stearate and calcium gluconate is required to effectively control the crosslinking reaction rate between sodium silicate and material B in the coal mine grouting material.

[0062] Comparison of Example 2 with Comparative Examples 5-8 reveals that when nano-aluminum hydroxide is not modified, or is modified only with KH570 or mercapto polyethylene glycol, the hydrophilicity of the aluminum hydroxide deteriorates and poor dispersion occurs in aqueous systems. This prevents the grouting material from tightly filling the pores and cracks in the coal rock mass, thereby reducing the mechanical strength of the coal filling and increasing the volume shrinkage, significantly affecting the performance of the grouting material.

[0063] 3. Industrial field test

[0064] To save experimental costs and enhance comparative results, the grouting materials of Examples 2, 4-5, and Comparative Examples 1-8 were selected for grouting and sealing in a field test at a coal mine. Representative test holes were selected to ensure consistency in drilling parameters, including a grouting pressure of 1.5 MPa, a hole diameter of 100 mm, and a hole depth of 10 m. After one month of field observation, changes in gas concentration in the test and comparison holes were recorded. Details are shown in Table 4:

[0065] Table 4 Industrial field test results

[0066]

[0067]

[0068] According to the data in Table 4, the gas extraction concentration in the boreholes plugged in Examples 2, 4-5 was significantly higher than that in Comparative Examples 1-8, and this difference became more pronounced with increasing extraction time. Specifically, the average gas extraction concentration in Examples 2, 4-5 was 6-13% higher than that in the Comparative Examples, and by day 30, the concentration was 20-30% higher. This indicates that the gas extraction concentration decay rate in the Examples was significantly reduced. This result confirms that the grouting material of the present invention performs well in plugging cracks and pores in coal and rock masses, effectively preventing gas leakage and reducing gas leakage inside and outside the borehole, thereby significantly extending the effective extraction period of the borehole.

[0069] The above embodiments are merely examples provided to illustrate the present invention and are not intended to limit the possible implementations of the present invention. Based on the disclosure of the present invention, those skilled in the relevant art may make various modifications and adjustments. It is neither possible nor necessary to enumerate all possible implementations. Any modification, equivalent substitution, or improvement made within the basic principles and scope of the present invention shall be deemed to fall within the scope of protection of the present invention.

Claims

1. A new type of low-carbon room temperature grouting material for mining, characterized in that: Including material A and material B with a mass ratio of 4:1: Material A includes the following raw materials in parts by weight: 20-45 parts of sodium silicate, 3-8 parts of modified aluminum hydroxide, 3-10 parts of nano silicon powder, 1-3 parts of calcium stearate, 1-5 parts of calcium gluconate, 1-3 parts of polycarboxylate water reducer, 1-10 parts of auxiliary agent, and the balance is water; Material B includes the following raw materials in parts by weight: 5-15 parts of boric acid, 1-3 parts of citric acid, 0.5-1 parts of surfactant, and the balance of water; The preparation method of the modified aluminum hydroxide comprises: mixing aluminum hydroxide powder and KH570 at a mass ratio of 100:5-10 for 30-60 minutes; Then, 3-5 wt % of mercapto polyethylene glycol is added to the aluminum hydroxide, and the mixture is stirred and mixed for 30-60 minutes under ultraviolet light, and dried to obtain modified aluminum hydroxide.

2. A new low-carbon room temperature grouting material for mining according to claim 1, characterized in that: The ultraviolet light intensity is 10-30 mW / cm 2 The stirring and mixing speed is 300-600r / min; the drying temperature is 80-100℃, and the drying time is 40-80min.

3. A new low-carbon room-temperature grouting material for mining according to claim 1, characterized in that: The average particle size of the nano-silicon powder is 50-150 nm, and the average particle size of the modified aluminum hydroxide is 200-500 nm.

4. A new low-carbon room-temperature grouting material for mining according to claim 3, characterized in that: The average particle size of the nano-silicon powder is 50-100 nm, and the average particle size of the modified aluminum hydroxide is 300-400 nm.

5. A new type of low-carbon room temperature grouting material for mining according to claim 1, characterized in that: The mercapto polyethylene glycol is monomercapto polyethylene glycol and / or dimercapto polyethylene glycol, and the polyethylene glycol involved is PEG500-PEG5000.

6. A new type of low-carbon room temperature grouting material for mining according to claim 1, characterized in that: The surfactant of the material B is at least one of sodium dodecylbenzene sulfonate, polysorbate 80, sodium lauryl sulfate, and lignin sulfonate.

7. A new low-carbon room-temperature grouting material for mining according to claim 1, characterized in that: The auxiliary agent of the material A includes at least one of a defoaming agent and a coupling agent, wherein the defoaming agent is 0.5-5 parts and the coupling agent is 1-5 parts.

8. A new low-carbon room-temperature grouting material for mining according to claim 7, characterized in that: The defoaming agent is at least one of polydimethylsiloxane and tributyl phosphate, and the coupling agent is at least one of a silane coupling agent and an aluminate coupling agent.

9. A new low-carbon room temperature grouting material for mining according to any one of claims 1 to 8, characterized in that: The specific steps include: The raw materials in material A are weighed according to stoichiometric measurement, and stirred at a water-cement ratio of 0.3 to 0.5:1 to obtain material A slurry; the raw materials in material B are weighed according to stoichiometric measurement, and stirred at a water-cement ratio of 0.3 to 0.5:1 to obtain material B slurry.

10. Use of the novel low-carbon room-temperature grouting material for mining according to any one of claims 1 to 8 or the novel low-carbon room-temperature grouting material for mining prepared according to claim 9 in coal mines, characterized in that: The following steps are involved: Material A and material B are sucked into the mixing pipe using a grouting pump, and then injected into the grouting holes drilled in advance.

Images