Inorganic reinforced hole sealing agent and preparation method thereof

Abstract

The invention belongs to the technical field of hole sealing materials, and provides an inorganic reinforced hole sealing agent and a preparation method thereof.The inorganic reinforced hole sealing agent is composed of a hole sealing material and water, and the hole sealing material is prepared from, by weight, 60-75 parts of Portland cement, 10-13 parts of fly ash, 18-23 parts of gypsum, 4-7 parts of inorganic fiber, 2-6 parts of expanding agent, 1-3 parts of water reducing agent and 2-5 parts of modified graphene. The preparation method comprises the following steps: step 1, uniformly mixing the Portland cement, the fly ash, the gypsum, the inorganic fiber, the expanding agent, the water reducing agent and the modified graphene in parts by weight to obtain a hole sealing material; and 2, adding water into the hole sealing material obtained in the step 1, and uniformly stirring and mixing to obtain the inorganic reinforced hole sealing agent. The inorganic reinforced hole sealing agent provided by the invention has the characteristics of no shrinkage, no dry crack, high reliability and simplicity in operation; and meanwhile, the expansion performance is excellent, the interior of a hole can be effectively sealed, and drilling air leakage channels are reduced.

Description

Technical Field

[0001] This invention belongs to the field of sealing material technology, specifically relating to an inorganic reinforcing sealing agent and its preparation method. Background Technology

[0002] Methane gas is a primary technical challenge encountered in mining operations. Underground coal seam gas drainage is an effective method for controlling coal seam gas. Drilling is a fundamental technical means of coal seam gas control. After drilling, the borehole generally needs to be sealed. The quality of the seal determines the effectiveness of the drainage. If the seal is not tight, it can easily lead to air and water leakage, thereby reducing the effectiveness of gas drainage. Conversely, if the seal is tight, it can effectively increase the gas concentration. Therefore, selecting appropriate sealing materials and preparation processes is of great significance.

[0003] Currently, the sealing materials used in coal seams are mostly polymer materials and cement mortar. The former has low compressive strength after sealing, is prone to deformation and shrinkage under rock stress, is somewhat toxic and flammable, some materials fail when exposed to water, has poor sealing performance, and is very expensive, making sealing costly. The latter, if silicate cement is used, does not expand after solidification but rather shrinks slightly. When sealing horizontal holes, it often forms a sealing gap at the top of the borehole, failing to fill the fracture zone at the top. If sulfoaluminate cement is used for consolidation, some microcracks will form internally, causing the material to lose its sealing effect.

[0004] In summary, since the above-mentioned sealing materials all have certain shortcomings, in order to better complete the coal mine gas control work and achieve high extraction concentration and high efficiency in gas extraction, it is urgent to develop a sealing material with excellent expansion performance, airtightness, high strength, low cost, and non-toxicity. Summary of the Invention

[0005] The purpose of this invention is to provide an inorganic reinforcing sealing agent and its preparation method, so as to solve one of the technical problems mentioned in the background art.

[0006] The objective of this invention can be achieved through the following technical solutions: The first aspect of this invention provides an inorganic reinforcing sealing agent, composed of a sealing material and water, wherein the sealing material comprises, by weight, the following raw materials: The composition comprises 60-75 parts silicate cement, 10-13 parts fly ash, 18-23 parts gypsum, 4-7 parts inorganic fiber, 2-6 parts expanding agent, 1-3 parts water-reducing agent, and 2-5 parts modified graphene; wherein the preparation steps of the modified graphene are as follows: Graphene oxide was added to deionized water and anhydrous ethanol and ultrasonically dispersed until uniform. Concentrated ammonia was added dropwise, and stirring was continued for 15-20 minutes. Hexadecyltrimethoxysilane and tetraethyl orthosilicate were added, and stirring was continued for 10-12 hours. After centrifugation, filtration, washing, and vacuum drying, modified graphene was obtained.

[0007] As a preferred embodiment of the present invention, the ratio of graphene oxide, deionized water, anhydrous ethanol, concentrated ammonia, hexadecyltrimethoxysilane and tetraethyl orthosilicate is 0.20-0.25 g: 20 mL: 80 mL: 0.02-0.05 mL: 0.2-0.5 mL: 0.28-0.7 mL.

[0008] As a preferred embodiment of the present invention, the graphene oxide is prepared by the Hummers method.

[0009] As a preferred embodiment of the present invention, the mass ratio of the sealing material to water is 1:0.4 to 0.7.

[0010] As a preferred embodiment of the present invention, the gypsum is at least one of anhydrite and dihydrate gypsum.

[0011] In a preferred embodiment of the present invention, the inorganic fiber is one of basalt fiber and glass fiber. The incorporation of inorganic fibers helps to suppress crack development and can also effectively resist excess expansion stress caused by excessive expansion.

[0012] In a preferred embodiment of the present invention, the expanding agent is at least one of bauxite, calcium sulfoaluminate, magnesium oxide, and calcium oxide.

[0013] In a preferred embodiment of the present invention, the particle size of the expanding agent is 5 to 15 μm.

[0014] In a preferred embodiment of the present invention, the water-reducing agent is a polycarboxylate water-reducing agent. The incorporation of the water-reducing agent can improve the fluidity and strength of the slurry and reduce the shrinkage and deformation of the inorganic reinforcing and sealing agent.

[0015] A second aspect of this invention provides a method for preparing an inorganic reinforcing sealing agent, comprising the following preparation steps: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0016] The beneficial effects of this invention are: The inorganic reinforcing and sealing agent in this invention is prepared by uniformly mixing silicate cement, fly ash, gypsum, inorganic fibers, expanding agents, water-reducing agents, and modified graphene in a reasonable proportion. The components in the raw materials work synergistically, resulting in an inorganic reinforcing and sealing agent with good expansion effect, strong fluidity, and good sealing performance. Furthermore, the graphene oxide added to the raw materials has a high specific surface area and excellent mechanical properties. The appropriate addition of graphene oxide can significantly improve the mechanical properties of silicate cement, enhancing the compressive and flexural strength of the cement matrix. In addition, the addition of graphene oxide can accelerate cement hydration and improve the microstructure of hydrated crystals. However, due to the large number of hydrophilic groups on the surface of graphene oxide, severe aggregation easily occurs in water. Therefore, in this invention, hexadecyltrimethoxysilane and tetraethyl orthosilicate are used as silicon sources to load silica onto the surface of graphene oxide, resulting in modified graphene oxide. The surface loading of graphene oxide with silica effectively improves the hydrophobic properties of the graphene oxide surface and enhances its dispersibility in raw materials. At the same time, silica can improve the compressive strength and durability of cement-based materials, thereby further enhancing the mechanical strength and durability of inorganic reinforcing and sealing agents.

[0017] The inorganic reinforcing and sealing agent provided by this invention has the characteristics of not shrinking, not cracking, high reliability, and simple operation; at the same time, it has excellent expansion performance, which can effectively seal the hole, reduce the gas leakage channel in the borehole, and thus extend the gas extraction period and increase the gas extraction concentration during the operation.

[0018] The preparation method provided by this invention is simple, the raw materials are readily available, and the prepared inorganic reinforcing sealing agent has high uniformity and good stability, making it suitable for large-scale industrial production and application. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Obviously, the following description is merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios without any inventive effort. Furthermore, it is understood that although the effort involved in such development may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0021] However, there may be instances where unnecessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of essentially the same structure may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the following description is provided to enable those skilled in the art to fully understand this application and is not intended to limit the subject matter of the claims.

[0022] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions, and all technical features and optional technical features of this application can be combined to form new technical solutions.

[0023] The graphene oxide used in the embodiments and comparative examples of this invention was prepared by the Hummers method, and the specific steps are as follows: 0.3 g of graphene was added to 2.4 mL of concentrated sulfuric acid and stirred for 0.5 h. Then, 0.5 g of sodium nitrate was added, the temperature was raised to 80 °C, and stirring was continued for 5 h. Then, 12 mL of concentrated sulfuric acid was added, and the temperature was controlled below 5 °C. Then, 1.5 g of potassium permanganate was slowly added, the temperature was raised to 35 °C, and stirring was continued for 2 h. Then, 70 mL of deionized water and 2 mL of H2O2 (mass fraction of 30%) were added. The mixture was centrifuged, washed with 5% HCl and deionized water until the pH value was 7, and finally dried in a vacuum drying oven at 60 °C for 10 h to obtain graphene oxide.

[0024] Example 1

[0025] This embodiment provides a modified graphene, the preparation steps of which are as follows: 0.20 g of graphene oxide was added to 20 mL of deionized water and 80 mL of anhydrous ethanol and ultrasonically dispersed until uniform. 0.025 mL of concentrated ammonia (28% concentration) was added dropwise, and stirring was continued for 15 min. 0.2 mL of hexadecyltrimethoxysilane and 0.28 mL of tetraethyl orthosilicate were added, and stirring was continued for 12 h. After centrifugation and filtration, the modified graphene was washed three times with anhydrous ethanol and deionized water, respectively, and then vacuum dried.

[0026] Example 2

[0027] This embodiment provides a modified graphene, the preparation steps of which are as follows: 0.22 g of graphene oxide was added to 20 mL of deionized water and 80 mL of anhydrous ethanol and ultrasonically dispersed until uniform. 0.025 mL of concentrated ammonia (28% concentration) was added dropwise, and stirring was continued for 15 min. 0.35 mL of hexadecyltrimethoxysilane and 0.5 mL of tetraethyl orthosilicate were added, and stirring was continued for 12 h. After centrifugation and filtration, the modified graphene was washed three times with anhydrous ethanol and deionized water, respectively, and then vacuum dried.

[0028] Example 3

[0029] This embodiment provides a modified graphene, the preparation steps of which are as follows: 0.25 g of graphene oxide was added to 20 mL of deionized water and 80 mL of anhydrous ethanol and ultrasonically dispersed until uniform. 0.04 mL of concentrated ammonia (28%) was added dropwise, and stirring was continued for 20 min. 0.5 mL of hexadecyltrimethoxysilane and 0.7 mL of tetraethyl orthosilicate were added, and stirring was continued for 12 h. After centrifugation and filtration, the modified graphene was washed three times with anhydrous ethanol and deionized water, respectively, and then vacuum dried.

[0030] Example 4

[0031] This embodiment provides an inorganic reinforcing sealing agent, composed of sealing material and water. The sealing material, by weight, includes the following raw materials: 60 parts silicate cement, 10 parts fly ash, 18 parts anhydrite, 4 parts basalt fiber, 2 parts bauxite (particle size 5μm), 1 part polycarboxylate superplasticizer, and 2 parts modified graphene from Example 1.

[0032] The mass ratio of sealing material to water is 1:0.4; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0033] Example 5

[0034] This embodiment provides an inorganic reinforcing sealing agent, composed of sealing material and water. The sealing material, by weight, includes the following raw materials: 60 parts silicate cement, 10 parts fly ash, 18 parts anhydrite, 4 parts basalt fiber, 2 parts bauxite (particle size 5μm), 1 part polycarboxylate superplasticizer, and 2 parts modified graphene from Example 2.

[0035] The mass ratio of sealing material to water is 1:0.4; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0036] Example 6

[0037] This embodiment provides an inorganic reinforcing sealing agent, composed of sealing material and water. The sealing material, by weight, includes the following raw materials: 60 parts silicate cement, 10 parts fly ash, 18 parts anhydrite, 4 parts basalt fiber, 2 parts bauxite (particle size 5μm), 1 part polycarboxylate superplasticizer, and 2 parts modified graphene from Example 3.

[0038] The mass ratio of sealing material to water is 1:0.4; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0039] Example 7

[0040] This embodiment provides an inorganic reinforcing sealing agent, composed of sealing material and water. The sealing material, by weight, includes the following raw materials: 75 parts silicate cement, 13 parts fly ash, 23 parts anhydrite, 7 parts basalt fiber, 6 parts bauxite (particle size 5μm), 3 parts polycarboxylate superplasticizer, and 5 parts modified graphene from Example 1.

[0041] The mass ratio of sealing material to water is 1:0.6; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0042] Example 8

[0043] This embodiment provides an inorganic reinforcing sealing agent, composed of sealing material and water. The sealing material, by weight, includes the following raw materials: 65 parts silicate cement, 11 parts fly ash, 20 parts anhydrite, 5 parts basalt fiber, 4 parts bauxite (particle size 5μm), 2 parts polycarboxylate superplasticizer, and 4 parts modified graphene from Example 1.

[0044] The mass ratio of sealing material to water is 1:0.5; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0045] Example 9

[0046] This embodiment provides an inorganic reinforcing sealing agent, composed of sealing material and water. The sealing material, by weight, includes the following raw materials: 70 parts silicate cement, 10 parts fly ash, 20 parts anhydrite, 6 parts glass fiber, 4 parts magnesium oxide (particle size 10 μm), 3 parts polycarboxylate superplasticizer, and 5 parts modified graphene from Example 1.

[0047] The mass ratio of sealing material to water is 1:0.7; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0048] Comparative Example 1

[0049] This comparative example provides an inorganic reinforcing sealing agent, composed of sealing material and water. Compared with Example 4, the sealing material raw material does not contain modified graphene. The sealing material, by weight, includes the following raw materials: 60 parts silicate cement, 10 parts fly ash, 18 parts anhydrite, 4 parts basalt fiber, 2 parts bauxite (particle size 5μm), and 1 part polycarboxylate superplasticizer.

[0050] The mass ratio of sealing material to water is 1:0.4; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent and water-reducing agent evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0051] Comparative Example 2

[0052] This comparative example provides an inorganic reinforcing sealing agent, composed of sealing material and water. Compared with Example 4, only graphene oxide is added to the sealing material raw material. The sealing material, by weight, includes the following raw materials: 60 parts silicate cement, 10 parts fly ash, 18 parts anhydrite, 4 parts basalt fiber, 2 parts bauxite (particle size 5μm), 1 part polycarboxylate superplasticizer, and 2 parts graphene oxide.

[0053] The mass ratio of sealing material to water is 1:0.4; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and graphene oxide evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0054] Comparative Example 3

[0055] This comparative example provides an inorganic reinforcing sealing agent, composed of sealing material and water. Compared with Example 4, the amount of modified graphene in the sealing material raw material is different. The sealing material, by weight, includes the following raw materials: 60 parts silicate cement, 10 parts fly ash, 18 parts anhydrite, 4 parts basalt fiber, 2 parts bauxite (particle size 5μm), 1 part polycarboxylate superplasticizer, and 1 part modified graphene from Example 1.

[0056] The mass ratio of sealing material to water is 1:0.4; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0057] Comparative Example 4

[0058] This comparative example provides an inorganic reinforcing sealing agent, composed of sealing material and water. Compared with Example 7, the amount of modified graphene in the sealing material raw material is different. The sealing material, by weight, includes the following raw materials: 75 parts silicate cement, 13 parts fly ash, 23 parts anhydrite, 7 parts basalt fiber, 6 parts bauxite (particle size 5μm), 3 parts polycarboxylate superplasticizer, and 6.5 parts modified graphene from Example 1.

[0059] The mass ratio of sealing material to water is 1:0.6; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0060] Comparative Example 5

[0061] This comparative example provides an inorganic reinforcing sealing agent, composed of sealing material and water. Compared with Example 4, the amount of raw materials used in the sealing material is different. The sealing material, by weight, includes the following raw materials: 55 parts silicate cement, 10 parts fly ash, 18 parts anhydrite, 4 parts basalt fiber, 2 parts bauxite (particle size 5μm), 1 part polycarboxylate superplasticizer, and 2 parts modified graphene from Example 1.

[0062] The mass ratio of sealing material to water is 1:0.4; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0063] Comparative Example 6

[0064] This comparative example provides an inorganic reinforcing sealing agent, composed of sealing material and water. Compared with Example 4, the amount of raw materials used in the sealing material is different. The sealing material, by weight, includes the following raw materials: 55 parts silicate cement, 10 parts fly ash, 15 parts anhydrite, 4 parts basalt fiber, 2 parts bauxite (particle size 5μm), 1 part polycarboxylate superplasticizer, and 2 parts modified graphene from Example 1.

[0065] The mass ratio of sealing material to water is 1:0.4; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0066] Comparative Example 7

[0067] This comparative example provides an inorganic reinforcing sealing agent, composed of sealing material and water. Compared with Example 4, the ratio of sealing material to water is different. The sealing material, by weight, includes the following raw materials: 60 parts silicate cement, 10 parts fly ash, 18 parts anhydrite, 4 parts basalt fiber, 2 parts bauxite (particle size 5μm), 1 part polycarboxylate superplasticizer, and 2 parts modified graphene from Example 1.

[0068] The mass ratio of sealing material to water is 1:0.3; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0069] Comparative Example 8

[0070] This comparative example provides an inorganic reinforcing sealing agent, composed of sealing material and water. Compared with Example 4, the ratio of sealing material to water is different. The sealing material, by weight, includes the following raw materials: 60 parts silicate cement, 10 parts fly ash, 18 parts anhydrite, 4 parts basalt fiber, 2 parts bauxite (particle size 5μm), 1 part polycarboxylate superplasticizer, and 2 parts modified graphene from Example 1.

[0071] The mass ratio of sealing material to water is 1:0.8; The preparation steps are as follows: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

[0072] The inorganic pore-reinforcing sealing agents obtained in Examples 4 to 9 and Comparative Examples 1 to 8 were subjected to performance tests, and the test results are shown in Table 1: Table 1

[0073] As can be seen from Table 1, compared with Comparative Examples 1-8, the inorganic reinforcing and sealing agents prepared in Examples 4-9 have the advantages of faster curing speed, higher expansion rate, and greater strength.

[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0075] It should be understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0076] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application are available on the market or can be prepared by existing methods.

[0077] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An inorganic reinforcing and sealing agent, characterized in that, Composed of sealing material and water, the sealing material comprises, by weight, the following raw materials: The composition comprises 60-75 parts silicate cement, 10-13 parts fly ash, 18-23 parts gypsum, 4-7 parts inorganic fiber, 2-6 parts expanding agent, 1-3 parts water-reducing agent, and 2-5 parts modified graphene; wherein the preparation steps of the modified graphene are as follows: Graphene oxide was added to deionized water and anhydrous ethanol and ultrasonically dispersed until uniform. Concentrated ammonia was added dropwise, and stirring was continued for 15-20 minutes. Hexadecyltrimethoxysilane and tetraethyl orthosilicate were added, and stirring was continued for 10-12 hours. After centrifugation, filtration, washing, and vacuum drying, modified graphene was obtained.

2. The inorganic reinforcing and sealing agent according to claim 1, characterized in that, The ratio of graphene oxide, deionized water, anhydrous ethanol, concentrated ammonia, hexadecyltrimethoxysilane and tetraethyl orthosilicate is 0.20-0.25 g: 20 mL: 80 mL: 0.02-0.05 mL: 0.2-0.5 mL: 0.28-0.7 mL.

3. The inorganic reinforcing and sealing agent according to claim 1, characterized in that, The graphene oxide was prepared using the Hummers method.

4. The inorganic reinforcing and sealing agent according to claim 1, characterized in that, The mass ratio of the sealing material to water is 1:0.4 to 0.

7.

5. The inorganic reinforcing and sealing agent according to claim 1, characterized in that, The gypsum is at least one of anhydrite and dihydrate gypsum.

6. The inorganic reinforcing and sealing agent according to claim 1, characterized in that, The inorganic fiber is one of basalt fiber and glass fiber.

7. The inorganic reinforcing and sealing agent according to claim 1, characterized in that, The expanding agent is at least one of bauxite, calcium sulfoaluminate, magnesium oxide, and calcium oxide.

8. The inorganic reinforcing and sealing agent according to claim 1, characterized in that, The particle size of the expanding agent is 5–15 μm.

9. An inorganic reinforcing and sealing agent according to claim 1, characterized in that, The water-reducing agent is a polycarboxylate water-reducing agent.

10. A method for preparing an inorganic reinforcing sealing agent according to any one of claims 1 to 9, characterized in that, The preparation steps include the following: Step 1: Mix silicate cement, fly ash, gypsum, inorganic fiber, expanding agent, water-reducing agent and modified graphene evenly according to the weight ratio to obtain sealing material; Step 2: Add water to the sealing material obtained in Step 1 and stir until uniform to obtain the inorganic reinforcing sealing agent.

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