Mining leaking stoppage reinforcing agent and preparation method thereof

Abstract

The invention discloses a mining leaking stoppage reinforcing agent and a preparation method thereof, and belongs to the technical field of mining repair materials, the mining leaking stoppage reinforcing agent comprises the following components: 20-40 parts of aluminate cement, 5-15 parts of an early strength agent, 8-20 parts of an expanding agent, 1-5 parts of activated nano silicon dioxide, 0.8-1.5 parts of a fiber reinforced material and 0.5-1.2 parts of a dispersing agent. Through the synergistic effect of the bacillus licheniformis fermentation product and the aluminate cement, the problems that a cement-based grouting material is slow in solidification and difficult to quickly support an area in urgent need of reinforcement are effectively solved. The TA-Fe-KGM complex effectively overcomes the defects that the plugging agent is easily influenced by environmental temperature and humidity, and the curing time and effect are difficult to control.

Description

Technical Field

[0001] The present invention relates to the technical field of mine repair materials, and in particular to a mine plugging and reinforcing agent and a preparation method thereof. Background Art

[0002] During mining operations, the complex geological structure within mines often leads to problems such as holes, rock cracks, and water gushing channels left behind after coal seam gas extraction. If these conditions are not properly addressed, the leakage of harmful gases such as methane can create a flammable and explosive environment, threatening the lives of underground workers. Liquid spills, such as water gushing, can not only disrupt the normal mining process but also cause serious accidents such as mine collapse. Therefore, effectively sealing these leaks and enhancing mine structural stability are crucial to ensuring safe production and improving mining efficiency.

[0003] While various mining plugging materials are currently used to some extent, they all have significant drawbacks. For example, common cement-based grouting materials are widely used due to their relatively low cost and widespread availability. However, cement-based materials exhibit poor setting speeds, typically requiring a long time to reach a certain strength. This inability to quickly provide sufficient support in areas in urgent need of reinforcement can lead to further loosening of the surrounding rock or soil due to a prolonged lack of effective support, increasing the risk of accidents.

[0004] Some inorganic gel-based plugging materials have significant limitations when injected into tiny cracks or pores. Due to their large particles or lack of fluidity, they struggle to fully penetrate the tiny gaps, preventing these leaks from being completely blocked, leading to poor overall plugging effectiveness. Once exposed to high-pressure gas or liquid, these unblocked microscopic gaps can become leak points, causing plugging failure.

[0005] In summary, existing mining plugging materials struggle to meet the complex and ever-changing demands of mine operations in terms of setting speed, early strength, and gas and liquid sealing. Developing a new type of mining plugging enhancer that can rapidly accelerate the setting of grouting materials, significantly improve early strength, and effectively seal gas and liquid leaks has become a critical issue in the mining industry, crucial for promoting safe and efficient mining operations.

[0006] Based on this, the present invention designs a mining plugging enhancer and a preparation method thereof to solve the above problems. Summary of the Invention

[0007] In view of the above-mentioned shortcomings of the prior art, the present invention provides a mining plugging enhancer, comprising the following components:

[0008] 20-40 parts of aluminate cement;

[0009] 5-15 parts of early strength agent; Bacillus licheniformis seed liquid is inoculated with , urea, fish peptone, yeast extract, 、 It is obtained by fermentation in a culture medium made of glucose, sodium citrate and Tween80;

[0010] 8-20 parts of expansion agent; obtained by mixing and grinding boron mud, carbide slag and sodium humate;

[0011] 1-5 parts of activated nano-silicon dioxide;

[0012] 0.8-1.5 parts of fiber reinforcement material; composed of pre-treated glass fiber and pre-treated basalt fiber in a mass ratio of 0.3-0.7:0.5-1.6;

[0013] 0.5-1.2 parts of dispersant; obtained by loading TA-Fe-KGM complex on mica-based nanocarrier.

[0014] A method for preparing the mining plugging and enhancing agent comprises the following steps:

[0015] S1. Preparation of early strength agent;

[0016] Will , urea, fish peptone, yeast extract, 、 , glucose, sodium citrate and Tween80 were dissolved in water to obtain a culture medium;

[0017] Inoculating Bacillus licheniformis seed solution into culture medium, performing shaking culture and then fermenting to obtain fermentation liquid;

[0018] After the fermentation liquid is cooled, cationic polyacrylamide is added for flocculation, and the precipitate is collected by centrifugation;

[0019] adding maltodextrin to the precipitate, spray drying and crushing;

[0020] Add silane coupling agent and mix with calcium nitrate to obtain early strength agent;

[0021] S2. Fiber pretreatment;

[0022] Sand the fiberglass using a belt sander and dry it;

[0023] The nano-silica and gelatin are mixed, water is added to prepare a suspension, the glass fiber is immersed in the suspension, taken out and dried to obtain the pretreated glass fiber;

[0024] Grind kaolin and add water to prepare a suspension, immerse the cleaned basalt fiber in the suspension, take it out and dry it to obtain pretreated basalt fiber;

[0025] S3. Nano-silica activation;

[0026] After mixing nano-silica and calcium carbonate powder, ball milling and sieving to obtain activated nano-silica;

[0027] S4. Prepare a dispersant;

[0028] The mica tailings are mixed with industrial-grade hydrofluoric acid, stirred, and spray-dried to obtain a mica-based nanocarrier;

[0029] Adding ferric sulfate to a konjac glucomannan solution to form an Fe-KGM complex, adding tannic acid and stirring to form a TA-Fe-KGM complex, and adding a mica-based nanocarrier dispersion dropwise to react to obtain a dispersant;

[0030] S5. Preparation of expansion agent;

[0031] Mix and grind boron mud, carbide slag and sodium humate to obtain an expansion agent;

[0032] S6. Raw material compounding;

[0033] The dispersant is prepared into a solution, stirred to form a uniform dispersion, and the activated nano-silica is added into the dispersion;

[0034] Adding pretreated glass fiber and pretreated basalt fiber into a mixer, dry-mixing to obtain mixed fiber, and adding the mixed fiber into a dispersion;

[0035] Dry-mixing aluminate cement, early strength agent and expansion agent, adding dispersion liquid and wet-mixing to form a mixture;

[0036] The mixture is granulated and dried by a granulator to obtain a mining plugging enhancer.

[0037] Furthermore, S1 is specifically: 25-35g / L , 15-25g / L urea, 8-12g / L fish peptone, 3-6g / L yeast extract, 1-1.5g / L , 0.5-1g / L , 5-10 g / L glucose, 1-3 g / L sodium citrate, and 0.1-0.3 g / L Tween80, dissolving each component in deionized water to obtain a culture medium;

[0038] Take the seed liquid of Bacillus licheniformis in the logarithmic growth period, inoculate it into the culture medium at an inoculum rate of 5-8wt%, and culture it under the conditions of 35-38℃ and 180-200r / min for 12-16h, controlling the dissolved oxygen ≥30%. When the pH reaches 0.8-1.0, fermentation begins and fermentation liquid is obtained;

[0039] After the fermentation broth is cooled, 0.05-0.1 wt% cationic polyacrylamide is added for flocculation, and the precipitate is collected by centrifugation at 4000-5000 rpm for 15-20 min, and washed three times with deionized water;

[0040] Add 2-5wt% maltodextrin to the precipitate, spray dry it at an inlet air temperature of 150-160℃ and an outlet air temperature of 70-80℃, and then grind it into powder by air flow. ≤10μm, ≤20μm;

[0041] Add 2-3wt% silane coupling agent and mix with 5-10wt% calcium nitrate after processing in a high-speed mixer to obtain an early strength agent.

[0042] Furthermore, the fermentation steps are as follows: maintaining 35-38°C for 0-24 hours, adjusting the pH to 7.0-7.5 with HCl solution, and DO ≥ 30%, so that ≥3.0;

[0043] Adjust the temperature to 28-30°C within 24-48 hours, stop adding acid, and allow the pH to naturally rise to 8.5-9.0. Control the DO at 20-30%.

[0044] Add 0.5-1g / L within 48-72h , reduce the stirring rate to 100-150r / min, and add 5-10g / L urea intermittently. When the concentration is ≤0.5 g / L, the fermentation is terminated to obtain a fermentation liquid.

[0045] Furthermore, the glass fiber pretreatment step is specifically as follows: using a belt sander, the glass fiber is passed through a conveyor belt at a uniform speed of 5-10m / min through the sand belt, the sand belt particle size is 200-400 mesh, the sanded glass fiber is spread flat on the conveyor belt, and passed through a drying channel equipped with an air purge device at a speed of 0.5-1m / min, and the temperature in the drying channel is maintained at 60-80°C;

[0046] Nano-silica and gelatin are mixed in a mass ratio of 1:2-3, deionized water is added to prepare a 1-3wt% suspension, glass fiber is immersed in the suspension for 20-30 minutes, taken out, and dried at 80-100°C for 1-2 hours to obtain pretreated glass fiber.

[0047] Furthermore, the pretreatment steps of the basalt fiber are as follows: placing the basalt fiber in a steam cleaning device, passing saturated steam with a pressure of 0.2-0.4 MPa and a temperature of 120-150°C, and treating for 15-25 minutes;

[0048] The kaolin is ground to a particle size of less than 20 μm, and deionized water is added to prepare a 15-20 wt% suspension. The basalt fiber is immersed in the suspension for 15-20 minutes, taken out and naturally dried at room temperature for 1-2 hours, and then placed in an oven at 80-100° C. for 2-3 hours to obtain the pretreated basalt fiber.

[0049] Furthermore, S3 is specifically as follows: after mixing nano-silica and calcium carbonate powder in a mass ratio of 1-5:0.5-1, adding the mixture into a planetary ball mill, using zirconia balls with a diameter of 3-5 mm, ball milling at a speed of 300-400 r / min for 2-3 hours, with a ball-to-material ratio of 10-12:1, and passing through a 180-200 mesh sieve after ball milling to obtain activated nano-silica.

[0050] Furthermore, S4 is specifically as follows: mica tailings are mixed with industrial-grade hydrofluoric acid at a solid-liquid ratio of 1:2-3, stirred in a water bath at 60-70°C for 2-3 hours, repeatedly washed with deionized water until neutral, and spray-dried to prepare a mica-based nanocarrier;

[0051] Konjac glucomannan is prepared into a 1-3 wt% aqueous solution, and ferric sulfate is added to the KGM solution. The mass ratio of Fe to KGM is 1:8-12, and the mixture is stirred at room temperature for 30-60 minutes to form an Fe-KGM complex. Tannic acid is added at a mass ratio of Fe-KGM complex to tannic acid of 1:0.3-0.6, and stirring is continued for 1-2 hours to form a TA-Fe-KGM complex. Under stirring, the mica-based nanocarrier dispersion with grafted polymer is slowly added dropwise. After the addition is completed, the mixture is reacted at 40-50°C for 2-3 hours to obtain a dispersant.

[0052] Furthermore, S5 is specifically as follows: boron mud, carbide slag and sodium humate with a particle size of ≤10 μm are put into a planetary ball mill in a mass ratio of 40-60:20-35:15-30, alumina balls are used as grinding media, the ball-to-material ratio is 6-8:1, and the mixture is mixed and ground at 300-400 r / min for 2-3 hours to obtain an expander.

[0053] Furthermore, S6 is specifically as follows: ethanol is added to the dispersant to prepare a solution with a concentration of 5-10wt%, and a high-speed disperser is used to stir at a speed of 1500-2000 r / min for 10-15 minutes to prepare a uniform dispersion liquid, and the activated nano-silica is slowly added to the dispersion liquid, and stirring is continued for 20-30 minutes;

[0054] Add the pretreated glass fiber and pretreated basalt fiber into a mixer and dry mix them at a speed of 300-500 r / min for 5-10 minutes to obtain mixed fibers. Add the mixed fibers into a dispersion containing activated nano-silica and stir at a speed of 100-200 r / min for 15-20 minutes.

[0055] Add aluminate cement, early strength agent and expansion agent into a powerful mixer, dry mix at a speed of 200-300 r / min for 10-15 minutes, add the dispersion containing fiber and nano-silica into the mixer, increase the speed to 500-800 r / min, and wet mix for 20-30 minutes to form a mixture with good fluidity and plasticity;

[0056] The mixture is granulated by a granulator to obtain particles with a particle size of 2-5 mm. The particles are placed in a drying oven and dried at a temperature of 60-80° C. for 2-3 hours to remove ethanol, thereby obtaining a mining plugging enhancer.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] 1. The present invention effectively solves the problem of slow solidification of cement-based grouting materials and difficulty in quickly supporting areas in urgent need of reinforcement through the synergistic effect of Bacillus licheniformis fermentation products and aluminate cement. The carbonic anhydrase produced during the fermentation process catalyzes the decomposition of urea to generate calcium carbonate nuclei that accelerate cement hydration and crystallization. Combined with the fast-hardening and early-strengthening properties of aluminate cement, the initial setting time is greatly shortened, and effective support can be quickly formed in emergency reinforcement scenarios in mines, reducing the risk of loosening and collapse of surrounding rock or soil due to lack of support; at the same time, the fermentation product and calcium nitrate promote the rapid hydration of tricalcium aluminate to generate calcium aluminoferrite, and nano-silica fills the pores and participates in the volcanic ash reaction. The synergy of multiple components significantly enhances the early compressive strength of the material, meeting the demand for rapid load-bearing in mine operations.

[0059] 2. This invention utilizes a TA-Fe-KGM complex to effectively overcome the drawbacks of leak-proofing agents, which are susceptible to environmental temperature and humidity, making curing time and effectiveness difficult to control. Konjac glucomannan (KGM) binds to water molecules through hydrogen bonds, buffering the effects of moisture on the cement matrix in high-humidity environments and preventing dilution of hydration products. At low temperatures, its molecular chains form a stable network that sustains the hydration reaction. The coordination complex formed with KGM and tannic acid regulates system activity through reversible changes in coordination bonds during temperature and humidity fluctuations, ensuring a stable setting process. When compounded with a strength accelerator, KGM regulates moisture distribution to create conditions for the strength accelerator to function. The complex's stable network structure ensures the strength accelerator's continued accelerated setting at low temperatures, achieving stable setting performance in complex mining environments such as high humidity and low temperatures, avoiding problems such as incomplete or slow curing caused by environmental factors.

[0060] 3. The present invention achieves excellent sealing performance through a multi-level structural design. The hydration of the expansion agent produces expansion products such as calcium aluminite, which fill cracks and holes from a macroscopic level and block the gas and liquid channels; the pretreated glass fiber and basalt fiber form a three-dimensional network structure, intercepting cement particles and enhancing the bonding with the rock mass, preventing the sealing material from falling off; nano-silica, with its high specific surface area and activity, fills microscopic pores and participates in the volcanic ash reaction to form a dense gel film, reducing the permeability of the material. Multiple components work together to form a multi-level sealing system from macroscopic to microscopic, which can achieve efficient sealing regardless of gas leakage or liquid gushing, effectively solving the problem of poor sealing effect of traditional materials in a two-phase medium environment, and significantly improving the safety of mine operations and mining efficiency. DETAILED DESCRIPTION

[0061] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0062] Example 1: This example provides a method for preparing a mining plugging enhancer, comprising the following steps:

[0063] S1. Preparation of early strength agent;

[0064] Press 35g / L , 25g / L urea, 12g / L fish peptone, 6g / L yeast extract, 1.5g / L , 1g / L , 10 g / L glucose, 3 g / L sodium citrate, and 0.3 g / L Tween80, and dissolving each component in deionized water to obtain a culture medium (the culture medium was pre-sterilized at 121°C for 20 minutes and then cooled to room temperature);

[0065] Take the seed liquid of Bacillus licheniformis in the logarithmic growth period, inoculate it into the culture medium at an inoculum rate of 8wt%, and culture it at 38℃ and 200r / min for 16h with the dissolved oxygen controlled at ≥30%. Fermentation begins when the value reaches 1.0;

[0066] Fermentation stage: maintain 38℃ for 0-24h, adjust pH to 7.5 with sterile HCl solution, DO≥30%, ≥3.0;

[0067] Adjust the temperature to 30°C within 24-48 hours, stop adding acid, and allow the pH to naturally rise to 9.0. Control the DO at 30%;

[0068] Add 1g / L within 48-72h , reduce the stirring rate to 150r / min, and add 10g / L urea intermittently. When the concentration is ≤0.5 g / L, the fermentation is terminated to obtain a fermentation liquid;

[0069] The fermentation broth was cooled to 25°C, 0.1 wt% cationic polyacrylamide was added for flocculation, and the precipitate was collected by centrifugation at 5000 rpm for 20 min and washed three times with deionized water.

[0070] Add 5wt% maltodextrin to the precipitate, spray dry it at an inlet air temperature of 160℃ and an outlet air temperature of 80℃, and then grind it into powder by air flow. ≤10μm, ≤20μm;

[0071] Add 3wt% silane coupling agent (KH-550) and process in a high-speed mixer (5000r / min, 10min), and then mix with 10wt% calcium nitrate to obtain an early strength agent;

[0072] S2. Fiber pretreatment;

[0073] Use a belt sander to pass the glass fiber through a conveyor belt at a uniform speed of 10m / min. The sanding belt has a 400-mesh grit. The surface roughness of the glass fiber is increased by physical sanding. The sanded glass fiber is spread flat on the conveyor belt and passed through a drying channel at a speed of 1m / min. The temperature in the drying channel is maintained at 80°C. At the same time, air purge devices are set on both sides of the channel (the compressed air generated by the oil-free air compressor is filtered and dried, and then transported to the purge nozzle through the air supply pipe). The air flow speed is 5m / s, and the air flow direction is 30 degrees to the glass fiber conveying direction to remove the tiny fiber dust and moisture generated by sanding.

[0074] Nano-silica and gelatin were mixed in a mass ratio of 1:3, and deionized water was added to prepare a 3wt% suspension. Glass fiber was immersed in the suspension for 30 minutes. The amino and other active groups in the gelatin molecules could combine with the hydroxyl groups on the surface of the nano-silica, and an adsorption layer was formed on the surface of the glass fiber. After removal, the pretreated glass fiber was dried at 100°C for 2 hours to obtain the pretreated glass fiber.

[0075] The basalt fiber was placed in a steam cleaning device and saturated steam with a pressure of 0.4 MPa and a temperature of 150°C was introduced for 25 minutes.

[0076] The kaolin was ground to a particle size of less than 20 μm, and deionized water was added to prepare a 20 wt% suspension. The basalt fiber was immersed in the suspension for 20 minutes, and then naturally dried at room temperature for 2 hours, and then dried in an oven at 100°C for 3 hours to obtain the pretreated basalt fiber.

[0077] S3. Nano-silica activation;

[0078] Nano-silica and calcium carbonate powder (particle size ≤ 10 μm) were mixed in a mass ratio of 5:1, added to a planetary ball mill, and ball-milled at 400 r / min for 3 h using zirconia balls with a diameter of 5 mm. The ball-to-material ratio was 12:1, and after ball milling, the mixture was passed through a 200-mesh sieve to obtain activated nano-silica.

[0079] S4. Prepare a dispersant;

[0080] Mica tailings were mixed with industrial-grade hydrofluoric acid (50% by mass) at a solid-liquid ratio of 1:3 and stirred in a 70°C water bath for 3 hours. The hydrofluoric acid was used to corrode the silicon and aluminum oxides in the mica tailings to achieve preliminary extraction and activation of the components. The mica-based nanocarriers were prepared by repeatedly washing with deionized water until neutral. The mixture was then spray-dried (inlet air temperature 200°C).

[0081] Konjac glucomannan (KGM) was prepared into a 3 wt% aqueous solution, and iron sulfate was added to the KGM solution. The mass ratio of Fe-KGM to KGM was 1:12, and the mixture was stirred at room temperature for 60 min to form an Fe-KGM complex. Tannic acid was added at a mass ratio of Fe-KGM complex to tannic acid (TA) of 1:0.6, and the mixture was stirred for 2 h. The phenolic hydroxyl groups in the tannic acid reacted with the Fe-KGM complex to form an Fe-KGM complex. A coordination reaction occurs to form a TA-Fe-KGM complex. Under stirring conditions, a dispersion of a polymer-grafted mica-based nanocarrier (solid content 15%) is slowly added dropwise. After the addition is complete, the mixture is reacted at 50°C for 3 hours. The TA-Fe-KGM complex interacts with the polymer chains on the surface of the mica-based nanocarrier through hydrogen bonds and electrostatic interactions, encapsulating and stabilizing the nanocarrier to obtain a dispersant.

[0082] S5. Preparation of expansion agent;

[0083] Boron mud, carbide slag and sodium humate with a particle size of ≤10 μm were put into a planetary ball mill at a mass ratio of 60:35:30, and alumina balls were used as grinding media with a ball-to-material ratio of 8:1. The mixture was mixed and ground at 400 r / min for 3 h to obtain an expansion agent.

[0084] S6. Weigh the raw materials;

[0085] 40 parts of aluminate cement; aluminate cement has the characteristics of rapid hardening and early strength, which can significantly shorten the setting time of the grouting material, thereby effectively preventing further leakage of gas and liquid;

[0086] 15 parts of early strength agent; promotes cement hydration reaction, so that in areas where the mine needs to quickly form a supporting structure, it can achieve a certain strength at an early stage to ensure operational safety;

[0087] 20 parts of expansion agent; it produces volume expansion during the hydration process, compensates for the shrinkage of the material during the hardening process, improves the adhesion with the crack or hole wall, and prevents secondary leakage;

[0088] 5 parts of activated nano-silica; nano-silica has an extremely high specific surface area and activity, which can fill the pores of cement stone, improve the microstructure, and increase the density and strength of the material. In the plugging of tiny pores or cracks, nano-silica can effectively improve the plugging performance of plugging materials;

[0089] 1.5 parts of fiber reinforcement material; pre-treated glass fiber and pre-treated basalt fiber are selected in a mass ratio of 0.7:1.6; the basalt fiber is 15mm long and 35μm in diameter; the glass fiber is 12mm long and 30μm in diameter; this enhances the toughness of the material, prevents crack expansion, and improves the impact resistance of the plugging material;

[0090] 1.2 parts of dispersant; it can effectively improve the dispersibility of raw materials, enhance the uniformity and fluidity of materials, ensure that all raw materials are fully mixed during the preparation process, and ensure the stability of the enhancer performance;

[0091] S7. Raw material compounding;

[0092] The dispersant was added to ethanol to prepare a solution with a concentration of 10 wt%, and stirred at a speed of 2000 r / min for 15 minutes using a high-speed disperser to prepare a uniform dispersion. The activated nano-silica was slowly added to the dispersion and stirred for 30 minutes to fully disperse the nano-silica and avoid agglomeration.

[0093] The pretreated glass fiber and pretreated basalt fiber were added to a blender and dry-mixed at a speed of 500 r / min for 10 minutes to obtain a mixed fiber. The mixed fiber was added to a dispersion containing activated nano-silica and stirred at a speed of 200 r / min for 20 minutes to allow the fiber surface to evenly absorb the dispersion and enhance the interfacial bonding between the fiber and other raw materials.

[0094] Add aluminate cement, early strength agent and expansion agent into a powerful mixer and dry mix them at a speed of 300 r / min for 15 minutes to ensure that the cement and admixtures are fully in contact. Add the dispersion containing fiber and nano-silica into the mixer and increase the speed to 800 r / min. Wet mix for 30 minutes to ensure that all raw materials are evenly distributed in the cement matrix to form a mixture with good fluidity and plasticity.

[0095] The mixture is granulated by a granulator to prepare particles with a particle size of 5 mm. The particles are placed in a drying oven and dried at a temperature of 80°C for 3 hours to remove ethanol, thereby increasing the strength of the particles and facilitating storage and transportation, thereby obtaining a mining plugging enhancer.

[0096] Example 2: This example provides a method for preparing a mining plugging enhancer, comprising the following steps:

[0097] S1. Preparation of early strength agent;

[0098] Press 25g / L , 15g / L urea, 8g / L fish peptone, 3g / L yeast extract, 1g / L , 0.5g / L , 5 g / L glucose, 1 g / L sodium citrate, and 0.1 g / L Tween80, and dissolving each component in deionized water to obtain a culture medium (the culture medium was pre-sterilized at 121°C for 20 minutes and then cooled to room temperature);

[0099] Take the seed liquid of Bacillus licheniformis in the logarithmic growth period, inoculate it into the culture medium at a rate of 5wt%, and culture it at 35℃ and 180r / min for 12h, controlling the dissolved oxygen to be ≥30%. Fermentation begins when the temperature reaches 0.8;

[0100] Fermentation stage: maintain 35℃ for 0-24h, adjust pH to 7.0 with sterile HCl solution, DO≥30%, ≥3.0;

[0101] Adjust the temperature to 28°C within 24-48 hours, stop adding acid, and allow the pH to naturally rise to 8.5. Control the DO at 20%;

[0102] Add 0.5g / L within 48-72h , reduce the stirring rate to 100r / min, and add 5g / L urea intermittently. When the concentration is ≤0.5 g / L, the fermentation is terminated to obtain a fermentation liquid;

[0103] The fermentation broth was cooled to 25°C, 0.05 wt% cationic polyacrylamide was added for flocculation, and the precipitate was collected by centrifugation at 4000 rpm for 15 min and washed three times with deionized water.

[0104] Add 2wt% maltodextrin to the precipitate, spray dry it at an inlet air temperature of 150℃ and an outlet air temperature of 70℃, and then grind it into powder by air flow. ≤10μm, ≤20μm;

[0105] Add 2wt% silane coupling agent (KH-550) and process in a high-speed mixer (5000r / min, 10min), and then mix with 5wt% calcium nitrate to obtain an early strength agent;

[0106] S2. Fiber pretreatment;

[0107] Use a belt sander to pass the glass fiber through a conveyor belt at a uniform speed of 5m / min. The sanding belt has a particle size of 200 mesh. The surface roughness of the glass fiber is increased by physical sanding. The sanded glass fiber is spread flat on the conveyor belt and passed through a drying channel at a speed of 0.5m / min. The temperature in the drying channel is maintained at 60°C. At the same time, air purge devices are set on both sides of the channel (the compressed air generated by the oil-free air compressor is filtered and dried, and then transported to the purge nozzle through the air supply pipe). The air flow speed is 5m / s, and the air flow direction is 30 degrees to the glass fiber conveying direction to remove the tiny fiber dust and moisture generated by sanding.

[0108] Nano-silica and gelatin were mixed in a mass ratio of 1:2, and deionized water was added to prepare a 1wt% suspension. Glass fiber was immersed in the suspension for 20 minutes. The amino and other active groups in the gelatin molecules could combine with the hydroxyl groups on the surface of the nano-silica, and an adsorption layer was formed on the surface of the glass fiber. After removal, the pretreated glass fiber was dried at 80°C for 1 hour to obtain the pretreated glass fiber.

[0109] The basalt fiber was placed in a steam cleaning device and saturated steam with a pressure of 0.2 MPa and a temperature of 120°C was introduced for 15 minutes.

[0110] The kaolin was ground to a particle size of less than 20 μm, and deionized water was added to prepare a 15 wt% suspension. The basalt fiber was immersed in the suspension for 15 minutes, and then naturally dried at room temperature for 1 hour, and then dried in an oven at 80°C for 2 hours to obtain the pretreated basalt fiber.

[0111] S3. Nano-silica activation;

[0112] Nano-silica and calcium carbonate powder (particle size ≤ 10 μm) were mixed in a mass ratio of 1:0.5, added to a planetary ball mill, and ball-milled at 300 r / min for 2 h using zirconia balls with a diameter of 3 mm, with a ball-to-material ratio of 10:1. After ball milling, the mixture was passed through a 180-mesh sieve to obtain activated nano-silica.

[0113] S4. Prepare a dispersant;

[0114] Mica tailings were mixed with industrial-grade hydrofluoric acid (40% by mass) at a solid-liquid ratio of 1:2 and stirred in a 60°C water bath for 2 hours. The hydrofluoric acid was used to corrode the silicon and aluminum oxides in the mica tailings to achieve preliminary extraction and activation of the components. The mixture was then repeatedly washed with deionized water until neutral, and then spray-dried (inlet air temperature 180°C) to prepare mica-based nanocarriers.

[0115] Konjac glucomannan (KGM) was prepared into a 1 wt% aqueous solution, and iron sulfate was added to the KGM solution. The mass ratio of Fe-KGM to KGM was 1:8, and the mixture was stirred at room temperature for 30 minutes to form an Fe-KGM complex. Tannic acid was added at a mass ratio of Fe-KGM complex to tannic acid (TA) of 1:0.3, and the mixture was stirred for 1 hour. The phenolic hydroxyl groups in the tannic acid reacted with the Fe-KGM complex to form an Fe-KGM complex. A coordination reaction occurs to form a TA-Fe-KGM complex. Under stirring conditions, a dispersion of a polymer-grafted mica-based nanocarrier (solid content 10%) is slowly added dropwise. After the addition is complete, the mixture is reacted at 40°C for 2 hours. The TA-Fe-KGM complex interacts with the polymer chains on the surface of the mica-based nanocarrier through hydrogen bonds and electrostatic interactions, encapsulating and stabilizing the nanocarrier to obtain a dispersant.

[0116] S5. Preparation of expansion agent;

[0117] Boron mud, carbide slag and sodium humate with a particle size of ≤10 μm were put into a planetary ball mill at a mass ratio of 40:20:15, and alumina balls were used as grinding media with a ball-to-material ratio of 6:1. The mixture was mixed and ground at 300 r / min for 2 h to obtain an expansion agent.

[0118] S6. Weigh the raw materials;

[0119] 20 parts of aluminate cement; aluminate cement has the characteristics of rapid hardening and early strength, which can significantly shorten the setting time of the grouting material, thereby effectively preventing further leakage of gas and liquid;

[0120] 5 parts of early strength agent; promotes cement hydration reaction, so that in areas where the mine needs to quickly form a supporting structure, it can achieve a certain strength at an early stage to ensure operational safety;

[0121] 8 parts of expansion agent; it produces volume expansion during the hydration process, compensates for the shrinkage of the material during the hardening process, improves the adhesion with the crack or hole wall, and prevents secondary leakage;

[0122] 1 part of activated nano-silica; nano-silica has a very high specific surface area and activity, which can fill the pores of cement stone, improve the microstructure, and increase the density and strength of the material. In the plugging of tiny pores or cracks, nano-silica can effectively improve the plugging performance of plugging materials;

[0123] 0.8 parts of fiber reinforcement material; pre-treated glass fiber and pre-treated basalt fiber are selected in a mass ratio of 0.3:0.5; the basalt fiber is 5mm long and 15μm in diameter; the glass fiber is 4mm long and 12μm in diameter; this enhances the toughness of the material, prevents crack expansion, and improves the impact resistance of the plugging material;

[0124] 0.5 parts of dispersant; it can effectively improve the dispersibility of raw materials, enhance the uniformity and fluidity of materials, make all raw materials fully mixed during the preparation process, and ensure the stability of the enhancer performance;

[0125] S7. Raw material compounding;

[0126] The dispersant was added to ethanol to prepare a solution with a concentration of 5wt%, and stirred at a speed of 1500r / min for 10min using a high-speed disperser to prepare a uniform dispersion. The activated nano-silica was slowly added to the dispersion and stirred for 20min to fully disperse the nano-silica and avoid agglomeration.

[0127] The pretreated glass fiber and pretreated basalt fiber were added to a blender and dry-mixed at a speed of 300-500 r / min for 5 minutes to obtain a mixed fiber. The mixed fiber was added to a dispersion containing activated nano-silica and stirred at a speed of 100 r / min for 15 minutes to allow the fiber surface to evenly absorb the dispersion and enhance the interfacial bonding between the fiber and other raw materials.

[0128] Add aluminate cement, early strength agent and expansion agent into a powerful mixer and dry mix them at a speed of 200 r / min for 10 minutes to ensure that the cement and the admixtures are fully in contact. Add the dispersion containing fiber and nano-silica into the mixer and increase the speed to 500 r / min. Wet mix for 20 minutes to ensure that all raw materials are evenly distributed in the cement matrix to form a mixture with good fluidity and plasticity.

[0129] The mixture is granulated by a granulator to prepare particles with a particle size of 2 mm. The particles are placed in a drying oven and dried at a temperature of 60° C. for 2 hours to remove ethanol, thereby increasing the strength of the particles and facilitating storage and transportation, thereby obtaining a mining plugging enhancer.

[0130] Example 3: This example provides a method for preparing a mining plugging enhancer, comprising the following steps:

[0131] S1. Preparation of early strength agent;

[0132] According to 32g / L , 21g / L urea, 9g / L fish peptone, 5g / L yeast extract, 1.2g / L , 0.7g / L , 7 g / L glucose, 2 g / L sodium citrate, and 0.2 g / L Tween80, and dissolving each component in deionized water to obtain a culture medium (the culture medium was pre-sterilized at 121°C for 20 minutes and then cooled to room temperature);

[0133] Take the seed liquid of Bacillus licheniformis in the logarithmic growth period, inoculate it into the culture medium at a rate of 6wt%, and culture it at 36℃ and 180r / min for 15h with the dissolved oxygen controlled at ≥30%. Fermentation begins when the temperature reaches 0.9;

[0134] Fermentation stage: maintain 36℃ for 0-24h, adjust pH to 7.3 with sterile HCl solution, DO≥30%, ≥3.0;

[0135] Adjust the temperature to 30°C within 24-48 hours, stop adding acid, and allow the pH to naturally rise to 8.7. The DO is controlled at 25%.

[0136] Add 0.6g / L within 48-72h , reduce the stirring rate to 120r / min, and add 8g / L urea intermittently. When the concentration is ≤0.5 g / L, the fermentation is terminated to obtain a fermentation liquid;

[0137] The fermentation broth was cooled to 25°C, 0.08 wt% cationic polyacrylamide was added for flocculation, and the precipitate was collected by centrifugation at 4300 rpm for 18 min and washed three times with deionized water.

[0138] Add 3wt% maltodextrin to the precipitate, spray dry it at an inlet air temperature of 157℃ and an outlet air temperature of 77℃, and then grind it into powder by air flow. ≤10μm, ≤20μm;

[0139] Add 2.8wt% of silane coupling agent (KH-550) and process in a high-speed mixer (5000r / min, 10min), and then mix with 8wt% of calcium nitrate to obtain an early strength agent;

[0140] S2. Fiber pretreatment;

[0141] Use a belt sander to pass the glass fiber through a conveyor belt at a uniform speed of 6m / min. The sanding belt has a 300-mesh grit. The surface roughness of the glass fiber is increased by physical sanding. The sanded glass fiber is spread flat on the conveyor belt and passed through a drying channel at a speed of 0.7m / min. The temperature in the drying channel is maintained at 70°C. At the same time, air purge devices are set on both sides of the channel (the compressed air generated by the oil-free air compressor is filtered and dried, and then transported to the purge nozzle through the air supply pipe). The air flow speed is 5m / s, and the air flow direction is 30 degrees to the glass fiber conveying direction to remove the tiny fiber dust and moisture generated by sanding.

[0142] Nano-silica and gelatin were mixed in a mass ratio of 1:2, and deionized water was added to prepare a 2wt% suspension. Glass fibers were immersed in the suspension for 26 minutes. The amino groups and other active groups in the gelatin molecules could combine with the hydroxyl groups on the surface of the nano-silica, and an adsorption layer was formed on the surface of the glass fibers. After removal, the pretreated glass fibers were dried at 95°C for 2 hours to obtain pretreated glass fibers.

[0143] The basalt fibers were placed in a steam cleaning device and saturated steam with a pressure of 0.2 MPa and a temperature of 140°C was introduced for 22 minutes.

[0144] Kaolin was ground to a particle size of less than 20 μm, and deionized water was added to prepare a 16 wt% suspension. Basalt fiber was immersed in the suspension for 17 minutes, then naturally dried at room temperature for 2 hours, and dried in an oven at 85°C for 2.5 hours to obtain pretreated basalt fiber.

[0145] S3. Nano-silica activation;

[0146] Nano-silica and calcium carbonate powder (particle size ≤ 10 μm) were mixed in a mass ratio of 4:0.7, added to a planetary ball mill, and ball-milled at 360 r / min for 2 h using zirconia balls with a diameter of 4 mm. The ball-to-material ratio was 11:1, and the mixture was passed through a 200-mesh sieve to obtain activated nano-silica.

[0147] S4. Prepare a dispersant;

[0148] Mica tailings were mixed with industrial-grade hydrofluoric acid (46% by mass) at a solid-liquid ratio of 1:2 and stirred in a 62°C water bath for 2 hours. The hydrofluoric acid was used to corrode the silicon and aluminum oxides in the mica tailings to achieve preliminary extraction and activation of the components. The mixture was then repeatedly washed with deionized water until neutral, and spray-dried (inlet air temperature 188°C) to prepare mica-based nanocarriers.

[0149] Konjac glucomannan (KGM) was prepared into a 2 wt% aqueous solution, and iron sulfate was added to the KGM solution. The mass ratio of Fe-KGM to KGM was 1:11, and the mixture was stirred at room temperature for 40 minutes to form an Fe-KGM complex. Tannic acid was added at a mass ratio of Fe-KGM complex to tannic acid (TA) of 1:0.5, and the mixture was stirred for 1 hour. The phenolic hydroxyl groups in the tannic acid reacted with the Fe-KGM complex to form an Fe-KGM complex. A coordination reaction occurs to form a TA-Fe-KGM complex. Under stirring conditions, a dispersion of a polymer-grafted mica-based nanocarrier (solid content 12%) is slowly added dropwise. After the addition is complete, the mixture is reacted at 43°C for 2 hours. The TA-Fe-KGM complex interacts with the polymer chains on the surface of the mica-based nanocarrier through hydrogen bonds and electrostatic interactions, encapsulating and stabilizing the nanocarrier to obtain a dispersant.

[0150] S5. Preparation of expansion agent;

[0151] Boron mud, carbide slag and sodium humate with a particle size of ≤10 μm were put into a planetary ball mill at a mass ratio of 52:28:20, and alumina balls were used as grinding media with a ball-to-material ratio of 7:1. The mixture was mixed and ground at 380 r / min for 2 h to obtain an expansion agent.

[0152] S6. Weigh the raw materials;

[0153] 32 parts of aluminate cement; aluminate cement has the characteristics of rapid hardening and early strength, which can significantly shorten the setting time of the grouting material, thereby effectively preventing further leakage of gas and liquid;

[0154] 12 parts of early strength agent; promotes cement hydration reaction, so that in areas where the mine needs to quickly form a supporting structure, it can achieve a certain strength at an early stage to ensure operational safety;

[0155] 12 parts of expansion agent; it produces volume expansion during the hydration process, compensates for the shrinkage of the material during the hardening process, improves the adhesion with the crack or hole wall, and prevents secondary leakage;

[0156] 3 parts of activated nano-silica; nano-silica has an extremely high specific surface area and activity, which can fill the pores of cement stone, improve the microstructure, and increase the density and strength of the material. In the plugging of tiny pores or cracks, nano-silica can effectively improve the plugging performance of plugging materials;

[0157] 1.2 parts of fiber reinforcement material; pre-treated glass fiber and pre-treated basalt fiber are selected in a mass ratio of 0.4:1.2; the basalt fiber is 10mm long and 20μm in diameter; the glass fiber is 8mm long and 22μm in diameter; this enhances the toughness of the material, prevents crack expansion, and improves the impact resistance of the plugging material;

[0158] 0.8 parts of dispersant; it can effectively improve the dispersibility of raw materials, enhance the uniformity and fluidity of materials, make all raw materials fully mixed during the preparation process, and ensure the stability of the enhancer performance;

[0159] S7. Raw material compounding;

[0160] The dispersant was added to ethanol to prepare a solution with a concentration of 8 wt %. The solution was stirred at 1700 rpm for 12 min using a high-speed disperser to prepare a uniform dispersion. The activated nano-silica was slowly added to the dispersion and stirred for 24 min to fully disperse the nano-silica and avoid agglomeration.

[0161] The pretreated glass fiber and pretreated basalt fiber were added to a blender and dry-mixed at a speed of 400 r / min for 8 minutes to obtain a mixed fiber. The mixed fiber was added to a dispersion containing activated nano-silica and stirred at a speed of 160 r / min for 17 minutes to allow the fiber surface to evenly absorb the dispersion and enhance the interfacial bonding between the fiber and other raw materials.

[0162] Add aluminate cement, early strength agent and expansion agent into a high-power mixer and dry-mix for 12 minutes at a speed of 270 r / min to ensure that the cement and admixtures are fully in contact. Add the dispersion containing fiber and nano-silica into the mixer and increase the speed to 700 r / min. Wet-mix for 22 minutes to ensure that all raw materials are evenly distributed in the cement matrix to form a mixture with good fluidity and plasticity.

[0163] The mixture is granulated by a granulator to obtain particles with a particle size of 4 mm. The particles are placed in a drying oven and dried at a temperature of 75° C. for 2.5 hours to remove ethanol, thereby increasing the strength of the particles and facilitating storage and transportation, thereby obtaining a mining plugging enhancer.

[0164] Comparative Example 1: This comparative example differs from Example 3 in that, when preparing the early strength agent, the Bacillus licheniformis seed solution is inoculated into the culture medium without fermentation, but is directly cooled and then cationic polyacrylamide is added for flocculation.

[0165] Comparative Example 2: This comparative example differs from Example 3 in that, when preparing the dispersant, konjac glucomannan is replaced with unprocessed and purified konjac flour.

[0166] Comparative Example 3: This comparative example differs from Example 3 in that konjac glucomannan is replaced with unprocessed and purified konjac flour, and the Bacillus licheniformis seed solution is inoculated into the culture medium without fermentation.

[0167] Experimental Example: 1. Initial setting time of the mining plugging enhancer (belonging to the ultra-fast hardening type cement) prepared according to GB / T1346-2011 standard at 25°C and 50% humidity (i.e., time to lose fluidity, s) and initial setting time at 2°C and 95% humidity (s).

[0168] The results are shown in Table 1;

[0169] Table 1

[0170]

[0171] As can be seen from the above table, the present invention is to introduce the Bacillus licheniformis seed solution into the , urea, fish peptone, yeast extract, 、 The culture medium made of glucose, sodium citrate and Tween80 was fermented, which significantly improved the initial coagulation rate.

[0172] The TA-Fe-KGM complex formed by processed and purified konjac glucomannan, iron sulfate and tannic acid effectively improves the stability of coagulation performance under low temperature and high humidity environments.

[0173] After the two are compounded, they have a synergistic effect on improving the initial setting speed and the stability of the solidification performance under low temperature and high humidity environments.

[0174] The principle is as follows: Bacillus licheniformis is rich in The carbonic anhydrase secreted by its metabolic activity plays a key catalytic role in decomposing urea into and . Quickly and in the system A chemical reaction occurs, forming calcium carbonate nuclei. These nuclei provide the initial framework for the crystallization of cement hydration products, greatly accelerating the crystallization process and effectively shortening the initial setting time. Aluminate cement inherently hardens and strengthens quickly. Its mineral components rapidly initiate hydration reactions upon contact with water, further promoting rapid setting of the entire system.

[0175] Konjac glucomannan (KGM), a hydrophilic polymer, forms numerous hydrogen bonds with water molecules thanks to its abundant hydroxyl groups on the molecular chain. In high-humidity environments, this helps buffer excessive water infiltration into the cement matrix, preventing excessive water dilution of hydration products and the subsequent hindrance of solidification. At low temperatures, the KGM molecular chains become less flexible, exhibiting a more ordered arrangement, forming a relatively stable three-dimensional network structure that maintains the continuous progress of the cement hydration reaction and prevents stagnation or delay due to temperature drops. It forms a stable TA-Fe-KGM complex through coordination with the hydroxyl groups of KGM and the phenolic hydroxyl groups of tannic acid (TA). When the temperature and humidity fluctuate, the coordination bonds can flexibly adjust the microstructure and reactivity of the system through reversible breaking and reorganization, ensuring that the solidification process is not disturbed by the environment and achieving initial coagulation stably and efficiently.

[0176] The calcium carbonate nuclei generated by the accelerator provide numerous starting points for cement hydration, accelerating the formation of hydration products. The TA-Fe-KGM complex, with its control over water molecules and stable network structure, ensures a relatively stable reaction environment during the initial stages of cement hydration, creating a suitable microenvironment for the accelerator to function. In high-humidity environments, KGM absorbs excess moisture, preventing it from interfering with the formation of calcium carbonate nuclei in the accelerator and the cement hydration reaction. In low-temperature environments, the TA-Fe-KGM complex maintains the system's reactivity, allowing the accelerator to continue its accelerating effect, jointly promoting rapid cement setting and significantly increasing the initial setting rate.

[0177] 2. The mining plugging enhancer prepared according to the GB / T17671-2021 standard test has a 2h compressive strength (MPa), 4h compressive strength (MPa), 8h compressive strength (MPa) and 24h compressive strength (MPa) after curing at 2°C and 95% humidity.

[0178] The results are shown in Table 2;

[0179] Table 2

[0180]

[0181] As can be seen from the above table, the early compressive strength was significantly improved by inoculating the Bacillus licheniformis seed liquid into the culture medium made from the above raw materials and then fermenting it.

[0182] The principle is as follows: the fermentation products of Bacillus licheniformis in the early strength agent, in addition to generating calcium carbonate crystal nuclei to accelerate initial setting, also work together with calcium nitrate to promote cement hydration reaction. On the one hand, it provides sufficient raw materials for the formation of cement hydration products, and on the other hand, it promotes the hydration reaction of tricalcium aluminate, quickly generating a large amount of ettringite. Etringite grows in the form of needle- or rod-shaped crystals, interweaving to form a dense network structure, giving the material high early strength.

[0183] 3. The examples and comparative examples were tested for their impermeability grades according to GB50164-2011 (P8 indicates the concrete can withstand a hydrostatic pressure of 0.8 MPa or higher, and concrete with an impermeability grade ≥ P6 is considered impermeable concrete).

[0184] According to API Std 65-2 (2010) standard, the gas permeability is tested (mD: millidarcy).

[0185] The results are shown in Table 3;

[0186] Table 3

[0187]

[0188] As can be seen from the above table, the mining plugging enhancer prepared by the present invention exhibits excellent sealing performance in a gas and liquid two-phase medium environment and has excellent anti-leakage ability.

[0189] The principle is as follows: Boron mud, carbide slag, and other components in the expansion agent undergo a complex chemical reaction during hydration, producing products such as ettringite, which exhibits expansion properties. As the reaction proceeds, the ettringite crystals continue to grow and expand, tightly filling cracks and pores in the rock. This directly blocks the flow of gas and liquid at a macroscopic level, forming the first physical barrier. Sodium humate, acting as an expansion regulator, precisely controls the rate of the expansion reaction, ensuring that the expansion process is synchronized with the cement setting and hardening process, thus avoiding secondary leakage caused by premature or delayed expansion.

[0190] Glass fibers and basalt fibers form a three-dimensional network within the material. When used for plugging, the fiber network effectively traps cement particles, reducing the loss of cement slurry under pressure and improving the slurry's impermeability. In cracks or pores, the fibers act as bridges and anchors, strengthening the bond between the plugging material and the surrounding rock mass, preventing it from falling out under the impact of gas or liquid pressure and maintaining the stability of the plugging structure.

[0191] Nanosilica further optimizes the material's sealing properties at the microscopic scale. Its ability to fill tiny pores significantly reduces the material's internal porosity and gas permeability. Furthermore, the gel formed by the nanosilica's reaction with the volcanic ash not only fills the pores but also forms a dense gel film on the pore surface, further blocking gas and liquid penetration. The combined components, from the macroscopic filling of the expander, the network reinforcement of the fibers, to the microscopic densification of the nanosilica, form a multi-level structural sealing system from the macroscopic to the microscopic.

[0192] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A mining plugging enhancer, characterized in that: Includes the following components: 20-40 parts of aluminate cement; 5-15 parts of early strength agent; Bacillus licheniformis seed liquid is inoculated with , urea, fish peptone, yeast extract, 、 It is obtained by fermentation in a culture medium made of glucose, sodium citrate and Tween80; 8-20 parts of expansion agent; It is obtained by mixing and grinding boron mud, carbide slag and sodium humate; 1-5 parts of activated nano-silicon dioxide; 0.8-1.5 parts of fiber reinforcement material; composed of pre-treated glass fiber and pre-treated basalt fiber in a mass ratio of 0.3-0.7:0.5-1.6; 0.5-1.2 parts of dispersant; obtained by loading TA-Fe-KGM complex on mica-based nanocarrier.

2. A method for preparing the mining plugging enhancer according to claim 1, characterized in that: The following steps are involved: S1. Preparation of early strength agent; Will , urea, fish peptone, yeast extract, 、 , glucose, sodium citrate and Tween80 were dissolved in water to obtain a culture medium; Inoculating Bacillus licheniformis seed solution into culture medium, performing shaking culture and then fermenting to obtain fermentation liquid; After the fermentation liquid is cooled, cationic polyacrylamide is added for flocculation, and the precipitate is collected by centrifugation; adding maltodextrin to the precipitate, spray drying and crushing; Add silane coupling agent and mix with calcium nitrate to obtain early strength agent; S2. Fiber pretreatment; Sand the fiberglass using a belt sander and dry it; The nano-silica and gelatin are mixed, water is added to prepare a suspension, the glass fiber is immersed in the suspension, taken out and dried to obtain the pretreated glass fiber; Grind kaolin and add water to prepare a suspension, immerse the cleaned basalt fiber in the suspension, take it out and dry it to obtain pretreated basalt fiber; S3. Nano-silica activation; After mixing nano-silica and calcium carbonate powder, ball milling and sieving to obtain activated nano-silica; S4. Prepare a dispersant; The mica tailings are mixed with industrial-grade hydrofluoric acid, stirred, and spray-dried to obtain a mica-based nanocarrier; Adding ferric sulfate to a konjac glucomannan solution to form an Fe-KGM complex, adding tannic acid and stirring to form a TA-Fe-KGM complex, and adding a mica-based nanocarrier dispersion dropwise to react to obtain a dispersant; S5. Preparation of expansion agent; Mix and grind boron mud, carbide slag and sodium humate to obtain an expansion agent; S6. Raw material compounding; The dispersant is prepared into a solution, stirred to form a uniform dispersion, and the activated nano-silica is added into the dispersion; Adding pretreated glass fiber and pretreated basalt fiber into a mixer, dry-mixing to obtain mixed fiber, and adding the mixed fiber into a dispersion; Dry-mixing aluminate cement, early strength agent and expansion agent, adding dispersion liquid and wet-mixing to form a mixture; The mixture is granulated and dried by a granulator to obtain a mining plugging enhancer.

3. The method for preparing the mine plugging and enhancing agent according to claim 2, wherein: S1 is specifically: 25-35g / L , 15-25g / L urea, 8-12g / L fish peptone, 3-6g / L yeast extract, 1-1.5g / L , 0.5-1g / L , 5-10 g / L glucose, 1-3 g / L sodium citrate, and 0.1-0.3 g / L Tween80, dissolving each component in deionized water to obtain a culture medium; Take the seed liquid of Bacillus licheniformis in the logarithmic growth period, inoculate it into the culture medium at an inoculum rate of 5-8wt%, and culture it under the conditions of 35-38℃ and 180-200r / min for 12-16h, controlling the dissolved oxygen ≥30%. When the pH reaches 0.8-1.0, fermentation begins and fermentation liquid is obtained; After the fermentation broth is cooled, 0.05-0.1 wt% cationic polyacrylamide is added for flocculation, and the precipitate is collected by centrifugation at 4000-5000 rpm for 15-20 min, and washed three times with deionized water; Add 2-5wt% maltodextrin to the precipitate, spray dry it at an inlet air temperature of 150-160℃ and an outlet air temperature of 70-80℃, and then grind it into powder by air flow. ≤10μm, ≤20μm; Add 2-3wt% silane coupling agent and mix with 5-10wt% calcium nitrate after processing in a high-speed mixer to obtain an early strength agent.

4. The method for preparing the mining plugging and enhancing agent according to claim 2, wherein: The specific fermentation steps are: maintain 35-38℃ for 0-24h, adjust pH to 7.0-7.5 with HCl solution, DO ≥ 30%, and make ≥3.0; Adjust the temperature to 28-30°C within 24-48 hours, stop adding acid, and allow the pH to naturally rise to 8.5-9.

0. Control the DO at 20-30%. Add 0.5-1g / L within 48-72h , reduce the stirring rate to 100-150r / min, and add 5-10g / L urea intermittently. When the concentration is ≤0.5 g / L, the fermentation is terminated to obtain a fermentation liquid.

5. The method for preparing the mining plugging and reinforcing agent according to claim 2, wherein: The specific steps of glass fiber pretreatment are as follows: using a belt sander, the glass fiber is passed through a conveyor belt at a uniform speed of 5-10m / min through the sand belt, the sand belt particle size is 200-400 mesh, the polished glass fiber is spread flat on the conveyor belt, and passed through a drying channel equipped with an air purge device at a speed of 0.5-1m / min. The temperature in the drying channel is maintained at 60-80℃; Nano-silica and gelatin are mixed in a mass ratio of 1:2-3, deionized water is added to prepare a 1-3wt% suspension, glass fiber is immersed in the suspension for 20-30 minutes, taken out, and dried at 80-100°C for 1-2 hours to obtain pretreated glass fiber.

6. The method for preparing the mine plugging and enhancing agent according to claim 2, wherein: The specific pretreatment steps of basalt fiber are as follows: place the basalt fiber in a steam cleaning device, introduce saturated steam with a pressure of 0.2-0.4MPa and a temperature of 120-150℃, and treat for 15-25 minutes; The kaolin is ground to a particle size of less than 20 μm, and deionized water is added to prepare a 15-20 wt% suspension. The basalt fiber is immersed in the suspension for 15-20 minutes, taken out and naturally dried at room temperature for 1-2 hours, and then placed in an oven at 80-100° C. for 2-3 hours to obtain the pretreated basalt fiber.

7. The method for preparing the mining plugging and enhancing agent according to claim 2, wherein: S3 is specifically as follows: after mixing nano-silica and calcium carbonate powder in a mass ratio of 1-5:0.5-1, adding the mixture into a planetary ball mill, using zirconia balls with a diameter of 3-5 mm, ball milling at a speed of 300-400 r / min for 2-3 hours, with a ball-to-material ratio of 10-12:1, and passing through a 180-200 mesh sieve after ball milling to obtain activated nano-silica.

8. The method for preparing the mine plugging and enhancing agent according to claim 2, wherein: S4 is specifically as follows: mica tailings and industrial-grade hydrofluoric acid are mixed at a solid-liquid ratio of 1:2-3, stirred in a water bath at 60-70°C for 2-3 hours, repeatedly washed with deionized water until neutral, and spray-dried to prepare a mica-based nanocarrier; Konjac glucomannan is prepared into a 1-3 wt% aqueous solution, and ferric sulfate is added to the KGM solution. The mass ratio of Fe to KGM is 1:8-12, and the mixture is stirred at room temperature for 30-60 minutes to form an Fe-KGM complex. Tannic acid is added at a mass ratio of Fe-KGM complex to tannic acid of 1:0.3-0.6, and stirring is continued for 1-2 hours to form a TA-Fe-KGM complex. Under stirring, the mica-based nanocarrier dispersion with grafted polymer is slowly added dropwise. After the addition is completed, the mixture is reacted at 40-50°C for 2-3 hours to obtain a dispersant.

9. The method for preparing a mine plugging and enhancing agent according to claim 2, wherein: S5 is specifically as follows: Boron mud with a particle size of ≤10 μm, calcium carbide slag, and sodium humate are put into a planetary ball mill in a mass ratio of 40-60:20-35:15-30, alumina balls are used as grinding media, the ball-to-material ratio is 6-8:1, and the mixture is mixed and ground at 300-400 r / min for 2-3 hours to obtain an expander.

10. The method for preparing the mining plugging and enhancing agent according to claim 2, characterized in that: S6 is specifically as follows: adding ethanol to the dispersant to prepare a solution with a concentration of 5-10wt%, stirring at a speed of 1500-2000r / min using a high-speed disperser for 10-15min to prepare a uniform dispersion, slowly adding the activated nano-silica to the dispersion, and continuing to stir for 20-30min; Add the pretreated glass fiber and pretreated basalt fiber into a mixer and dry mix them at a speed of 300-500 r / min for 5-10 minutes to obtain mixed fibers. Add the mixed fibers into a dispersion containing activated nano-silica and stir at a speed of 100-200 r / min for 15-20 minutes. Add aluminate cement, early strength agent and expansion agent into a powerful mixer, dry mix at a speed of 200-300 r / min for 10-15 minutes, add the dispersion containing fiber and nano-silica into the mixer, increase the speed to 500-800 r / min, and wet mix for 20-30 minutes to form a mixture with good fluidity and plasticity; The mixture is granulated by a granulator to obtain particles with a particle size of 2-5 mm. The particles are placed in a drying oven and dried at a temperature of 60-80° C. for 2-3 hours to remove ethanol, thereby obtaining a mining plugging enhancer.

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