A mine inorganic reinforcing material and its preparation method

Abstract

The application relates to the technical field of mine reinforcing materials, and particularly discloses a mine inorganic reinforcing material and a preparation method thereof. The mine inorganic reinforcing material comprises the following raw materials: a sulphoaluminate cement, silica fume, dihydrate gypsum, lime, lithium sulfate, magnesium oxide micro-expansion agent, a polycarboxylate dispersant, hydroxypropyl methyl cellulose ether, metakaolin and pH-metal ion double-response composite functional powder. The pH-metal ion double-response composite functional powder is prepared by chemically grafting a complex unit containing a catechol structure onto a pH-responsive polymer. The sulphoaluminate cement is used as a cementing matrix to compound multiple inorganic additives, and the pH-metal ion double-response composite functional powder is simultaneously added, so that the reinforcing material has the basic advantages of single-component construction convenience, controllable setting, early strength, high flow state, micro-expansion and the like, and the water environment self-adaptive hydrodynamic anti-dispersion capacity.

Description

Technical Field

[0001] This application relates to the field of mining reinforcement materials technology, and more specifically, it relates to an inorganic mining reinforcement material and its preparation method. Background Technology

[0002] In my country's coal and metal mines, problems such as fractured surrounding rock, developed joints and fissures, roof delamination, and water inrush are common during tunnel excavation, face mining, and fault fracture zone management. These issues necessitate the use of grouting reinforcement materials for rapid support and sealing. As mining depths continue to extend below -800m, deep ground stress increases, significantly raising the probability of encountering adverse geological structures such as collapse columns, fault fracture zones, and water-bearing structures. The resulting roof falls, spalling, and water inrushes have become major threats to mine safety, placing comprehensive demands on grouting reinforcement materials, including high early strength, rapid setting, long-distance pumpability, environmental friendliness, and resistance to dynamic water erosion.

[0003] Currently, mining grouting reinforcement materials are mainly divided into two categories: organic chemical grouts and inorganic grouting materials. Organic chemical grouts mainly include polyurethane, phenolic, and polyurea polymer reinforcement materials, which have fast setting and good permeability, but have drawbacks such as high raw material costs, large heat release during reaction, flammability, easy aging, and irritation to the human body. Some products can even cause spontaneous combustion of coal seams within hours to one or two days after use, seriously threatening underground safe production. Among inorganic grouting materials, ordinary cement single-liquid grout has a long initial setting time, low early strength, and low stone formation rate, making it difficult to meet the requirements of rapid emergency reinforcement. Cement-water glass two-liquid grout is a two-component system, which has large on-site mixing errors, is prone to pipe blockage, uneven setting, poor durability, and is prone to shrinkage and cracking. In recent years, single-component inorganic reinforcement materials have been developed through optimization of the cement-mineral powder-gypsum-water-reducing agent system, achieving significant progress in rapid setting and early strength, and have gradually become the mainstream direction of mining grouting reinforcement.

[0004] Patent application CN119430848A discloses a high-strength inorganic mineral reinforcement material and its application method. The raw materials, by mass, include the following components: 50-90 parts cement, 10-50 parts mineral powder, 0.1-3 parts water-reducing agent, 0.1-5 parts accelerator, 0.1-3 parts POSS, and 30-50 parts water. This method involves uniformly mixing cement, mineral powder, water-reducing agent, accelerator, and POSS to obtain a powder. The powder is then added to water and stirred until a slurry is obtained. This slurry is injected into the area to be reinforced using a grouting pump. However, the rheological properties of the slurry lack adaptive response to changes in the external water environment. In conditions containing continuously flowing fissure water, it is easily diluted, washed away, and lost, failing to maintain the integrity of the slurry interface. This easily leads to a false reinforcement phenomenon, with significant deficiencies in stone formation rate, interfacial bonding performance, and post-contraction strength retention under dynamic water conditions. Summary of the Invention

[0005] In order to develop a single-component inorganic reinforcement material for mining that has self-responsive anti-dispersion capabilities in aquatic environments and can effectively avoid erosion and false reinforcement problems caused by flowing water, this application provides an inorganic reinforcement material for mining and its preparation method.

[0006] Firstly, this application provides an inorganic reinforcement material for mining, employing the following technical solution: An inorganic reinforcing material for mining applications comprises the following raw materials in parts by weight: 45-60 parts of sulfoaluminate cement, 5-15 parts of silica fume, 5-10 parts of gypsum dihydrate, 1-3 parts of lime, 0.5-3 parts of lithium sulfate, 1-5 parts of magnesium oxide micro-expansion agent, 0.2-1.5 parts of polycarboxylate dispersant, 0.1-0.8 parts of hydroxypropyl methylcellulose ether, 2-6 parts of metakaolin, and 1-2.5 parts of pH-metal ion dual-responsive composite functional powder; The pH-metal ion dual-responsive composite functional powder is prepared by chemically grafting complexing units containing catechol structures onto a pH-responsive polymer.

[0007] By adopting the above technical solution, using sulfoaluminate cement as the cementitious matrix, and combining it with silica fume, dihydrate gypsum, lime, lithium sulfate, magnesium oxide micro-expansion agent, polycarboxylate dispersant, hydroxypropyl methylcellulose ether, and metakaolin, the reinforcement material possesses the advantages of convenient single-component construction, controllable setting time, high early strength, excellent fluidity, micro-expansion in volume, environmental friendliness, and long-distance pumping capability. This ensures uniform particle dispersion, excellent water retention, and high density of the hardened stone body within the grout. Simultaneously, this application incorporates a pH-metal ion dual-responsive composite functional powder prepared by chemically grafting catechol complexing units onto a pH-responsive polymer. The integrated molecular structure formed by covalent grafting endows the grout with adaptive regulation capabilities in the water environment, enabling the grout to operate in strongly alkaline cement systems (pH...). 12-13) Maintain low viscosity to ensure mixing, pumping and grouting performance; at this time, the carboxyl groups on the main chain of the acrylic acid-acrylamide copolymer are fully dissociated to form anions, and the molecular chains are in an extended state due to the electrostatic repulsion between chain segments, forming a spatial steric hindrance dispersion of cement particles; when the slurry front comes into contact with the mine water, the pH at the slurry-mine water interface forms a continuous gradient from the cement alkaline zone (pH 12-13) across the neutral zone (pH 6-9) to the acidic zone (pH 3-6). In this pH gradient zone: (1) the carboxyl groups located on the slurry side interface layer change from the dissociated state to the protonated state, the molecular chain conformation changes from the extended state to the coiled state, and a dense entangled network is formed through inter-chain hydrogen bonds and hydrophobic association; (2) at the same time, the catechol structure located in the neutral-weakly acidic pH window (pH 5-7) reacts with the Fe in the mine water. 3+ Al 3+Isovalent metal ions form monodentate or bidentate coordination complexes, crosslinking multiple polymer chains into a three-dimensional network structure. Two types of response processes are simultaneously triggered within the interfacial pH gradient region, synergistically forming an interfacial cohesion barrier layer. This rapidly increases the viscosity and structural cohesion of the slurry interface, effectively resisting dilution and erosion by flowing water. It significantly improves the stone-forming rate and strength retention rate under flowing water conditions, overcoming the shortcomings of existing single-component inorganic reinforcement materials such as insufficient response to external water environments, poor resistance to dispersion by flowing water, and susceptibility to pseudo-reinforcement. It is suitable for long-term reinforcement and treatment of complex, fractured surrounding rock in deep mines with flowing water.

[0008] Secondly, this application provides a method for preparing an inorganic reinforcing material for mining, employing the following technical solution: A method for preparing an inorganic reinforcing material for mining includes the following steps: Sulfoaluminate cement, silica fume, gypsum dihydrate, lime, lithium sulfate, magnesium oxide micro-expansion agent, polycarboxylate dispersant, hydroxypropyl methylcellulose ether, and metakaolin are stirred at 18-25 r / min for 3 min. Then, pH-metal ion dual-responsive composite functional powder is added, and the mixture is stirred at 35-45 r / min for 5 min to obtain an inorganic reinforcing material for mining.

[0009] By adopting the above technical solution and using a differentiated stirring process to prepare inorganic reinforcing materials for mining, the inorganic substrate is first stirred at a low speed to avoid the stratification and sedimentation of powders with large density differences and the flying of dust, thus achieving preliminary uniform mixing of inorganic components. Then, the dual-response functional powder is added by stirring at a medium speed, which can ensure that the trace functional components are uniformly dispersed in a large amount of inorganic substrate, and will not damage the surface coating layer and organic molecular structure of the dual-response powder due to excessive shear force, effectively ensuring the consistency and stability of product batch performance.

[0010] Preferably, the magnesium oxide micro-expansion agent is prepared by mixing the magnesium oxide expansion agent for M-type concrete and the magnesium oxide expansion agent for S-type concrete with a 0.8-1.5wt% calcium stearate ethanol solution at 90-110℃, stirring, and then mixing the resulting products.

[0011] By adopting the above technical solution, the process of preparing micro-expansion agents by separately coating and then mixing the magnesium oxide expansion agents for M-type and S-type concrete can effectively avoid the selective adsorption and uneven coating problems caused by the difference in surface energy of the two magnesium oxides. By regulating the hydration rate of different active magnesium oxides through the hydrophobic coating layer of calcium stearate, the gradient release of early expansion of magnesium oxide expansion agent for M-type concrete and late expansion of magnesium oxide expansion agent for S-type concrete can be achieved, thus constructing a gapless shrinkage compensation system throughout the entire age, avoiding early rapid expansion and late delayed expansion defects, and improving the long-term volume stability and crack resistance of the stone body.

[0012] Preferably, the mass ratio of the magnesium oxide expansive agent for M-type concrete to the magnesium oxide expansive agent for S-type concrete is 6-7:3-4; The particle size of the magnesium oxide expansive agent for M-type concrete is 8-15μm, and the particle size of the magnesium oxide expansive agent for S-type concrete is 15-25μm.

[0013] By adopting the above technical solution, the magnesium oxide expansive agent for M-type and S-type concrete is designed with differentiated particle size, constructing a composite expansion system with a double-active gradient and a bimodal particle size distribution. The active magnesium oxide in the small particle size matches the particle size of the cement particles, is evenly distributed in the slurry, and has fully exposed hydration reaction sites. It can provide the main expansion amount by rapid hydration after the slurry solidifies, and timely compensate for the chemical shrinkage induced by cement hydration. The hydration reaction of the low-activity magnesium oxide in the large particle size is slow and delayed, and can continuously provide micro-expansion in the later stage of hardening, compensating for drying shrinkage and creep shrinkage. This composite system works synergistically with the expansion of ettringite generated in the early stage of cement hydration to form a three-level gradient expansion system covering the stone body from the plastic stage to the long-term hardening stage. There is no expansion vacuum period. Compared with a single active magnesium oxide micro-expansive agent, it effectively improves the expansion efficiency and long-term stability, avoids the defects of early rapid expansion and late delayed expansion, and can effectively prevent the stone body from separating from the surrounding rock interface and the generation of internal micro-cracks, significantly improving the long-term service performance of the reinforcement material.

[0014] Preferably, the preparation method of the pH-metal ion dual-response composite functional powder includes the following steps: Step 1: Dissolve 100 parts by weight of acrylic acid-acrylamide copolymer in deionized water to form a 6wt% aqueous solution, then add 8-15 parts by weight of catechol functional monomer, stir to dissolve, adjust the pH of the system to 5-5.5, then add 12-18 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-6 parts by weight of N-hydroxysuccinimide, and activate for 15 min; under nitrogen protection, react at 25℃ for 12-18 h to obtain the reaction solution; the acrylic acid-acrylamide copolymer is prepared by copolymerizing sodium acrylate and acrylamide in a molar ratio of (2-4):(6-8); Step 2: The reaction solution is subjected to ultrafiltration dialysis to obtain the mother liquor. 0.2-0.5 parts by weight of KH-570 silane coupling agent is added to the mother liquor, stirred evenly, spray dried, and sieved to obtain the pH-metal ion dual-response composite functional powder.

[0015] By adopting the above technical solution, the amidation grafting process covalently grafts catechol functional monomers onto the main chain of acrylic acid-acrylamide copolymer. The grafting reaction conditions are mild and the functional group retention rate is high, which can stably introduce pH-responsive carboxyl groups and metal ion complexation catechol bifunctional sites. Subsequently, KH-570 silane coupling agent is added to modify the surface of organic polymers by silanization. Without destroying the biresponsive structure, the interfacial compatibility between organic functional powders and inorganic cementitious substrates is effectively improved, avoiding powder agglomeration in inorganic slurry, ensuring uniform distribution of biresponsive functional units, and improving the stability of dynamic water anti-dispersion effect.

[0016] Preferably, in step 1, 100 parts by weight of acrylic acid-acrylamide copolymer are dissolved in deionized water to form a 6wt% aqueous solution, then 8-15 parts by weight of catechol functional monomers and 2-4 parts by weight of 2-acrylamido-2-methylpropanesulfonic acid are added, stirred and dissolved, the pH of the system is adjusted to 5-5.5, then 12-18 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-6 parts by weight of N-hydroxysuccinimide are added, and activated for 15 min; under nitrogen protection, the reaction is carried out at 25°C for 12-18 h to obtain the reaction solution.

[0017] By adopting the above technical solution, 2-acrylamido-2-methylpropanesulfonic acid is introduced simultaneously during the grafting reaction stage. This introduces hydrophilic sulfonic acid groups into the polymer backbone, significantly improving the mineralization resistance and sulfate interference resistance of the dual-response powder. It avoids the cation shielding of carboxyl dissociation and catechol complexation sites in high-salt mine water, enabling the powder to maintain good pH conformational transition and metal ion crosslinking ability in complex water environments with high mineralization and high sulfate content, thus greatly expanding the applicable working conditions of the reinforcement material.

[0018] Preferably, the catechol functional monomer is one or more of dopamine hydrochloride, gallic acid, and 3,4-dihydroxyphenylpropionic acid, and more preferably dopamine hydrochloride.

[0019] By adopting the above technical solution, dopamine hydrochloride is selected as the catechol functional monomer. Its molecule contains both a highly reactive primary amino group and a catechol chelating group, exhibiting excellent compatibility with the EDC / NHS amidation grafting system. The grafting conversion rate can reach over 85%, and the resulting amide bond has good chemical stability, not easily hydrolyzed in an aqueous environment. Simultaneously, dopamine exhibits good chemical stability against Fe2+ commonly found in mine water. 3+ Al 3+ Ca 2+ Plasma has extremely strong chelating ability and a pH response range covering 4.0 to 9.0, which can significantly improve the dynamic water dispersion resistance and environmental adaptability of reinforcement materials.

[0020] Preferably, in step 2, the reaction solution is subjected to ultrafiltration dialysis to obtain a mother liquor, and 1.5-3 parts by weight of composite aluminosilicate micro powder is added to the mother liquor, stirred evenly, spray-dried, and sieved to obtain the pH-metal ion dual-response composite functional powder.

[0021] By adopting the above technical solution, the composite aluminosilicate micro powder modifies the purified polymer mother liquor, forming a uniform inorganic coating layer on the surface of the organic functional powder during the spray drying process. This effectively reduces the interfacial polarity difference between the organic phase and the inorganic cementitious matrix, significantly improving the compatibility and dispersion uniformity of the two. At the same time, the composite aluminosilicate micro powder has stable chemical properties, does not participate in the cement hydration reaction, does not interfere with the dual-response core function, and can also improve the flowability and anti-moisture agglomeration performance of the powder, thereby enhancing the storage stability of the product.

[0022] Preferably, in step 2, the reaction solution is subjected to ultrafiltration dialysis to obtain a mother liquor. 1.5-3 parts by weight of composite aluminosilicate micro powder are added to the mother liquor. The mixture is first stirred at a speed of 150-250 r / min for 10 min, then heated to 50-55℃ and the pH is adjusted to 6-6.5. The mixture is stirred at a speed of 800-1200 r / min for 30 min, spray dried, and sieved to obtain the pH-metal ion dual-response composite functional powder.

[0023] By adopting the above technical solution, the micro powder is first fully wetted and dispersed by low-speed stirring to avoid the dry powder from clumping. Then, by moderately raising the temperature and adjusting the pH, the hydroxyl groups on the surface of the polymer and the silanol and aluminol groups on the surface of the micro powder undergo an interfacial dehydration condensation reaction to form Si-OC and Al-OC covalent association bonds. This upgrades the original simple physical adsorption coating to a physical-chemical composite combination, which greatly improves the bonding strength of the coating layer, prevents the coating layer from falling off during stirring and pumping, further enhances the organic-inorganic interfacial bonding force, and ensures the stable performance of the dual-response function.

[0024] Preferably, the composite aluminosilicate powder is a mixture of quartz powder, calcined kaolin, and diatomaceous earth in a mass ratio of (50-65):(25-35):15.

[0025] By adopting the above technical solutions, quartz micro powder provides a stable inorganic framework and chemical inertness, calcined kaolin provides abundant surface hydroxyl groups to ensure interfacial bonding strength, and the porous structure of diatomaceous earth enhances adsorption and anchoring effects. The synergistic effect of the three can form a uniform, dense and firmly bonded inorganic coating layer, while avoiding the introduction of highly active components that may interfere with the cement hydration process, thus ensuring the consistency and stability of product batch performance.

[0026] In summary, this application has the following beneficial effects: 1. This application uses sulfoaluminate cement as the cementitious matrix and combines it with a variety of inorganic additives. At the same time, it incorporates pH-metal ion dual-responsive composite functional powder, so that the reinforcement material has the basic advantages of single-component construction, controllable setting, early strength and high fluidity, and micro-expansion, as well as the water environment adaptive dynamic water anti-dispersion ability. It effectively solves the defects of existing single-component inorganic reinforcement materials that are easily diluted and washed away by dynamic water and are prone to false reinforcement. It is suitable for long-term reinforcement and treatment of complex dynamic water fractured surrounding rock in deep mines.

[0027] 2. This application uses composite aluminosilicate micro powder to modify the purified polymer mother liquor, forming a uniform inorganic coating layer on the surface of the organic functional powder. This effectively reduces the interfacial polarity difference between the organic phase and the inorganic cementitious matrix, significantly improves the compatibility and dispersion uniformity of the blend, and because of its stable chemical properties, it does not participate in cement hydration and does not interfere with the dual-response core function. It can also improve the powder's flowability and anti-moisture agglomeration performance, and enhance the product's storage stability.

[0028] 3. This application uses a process of separately coating M-type and S-type concrete magnesium oxide expansion agents and then mixing them to prepare micro-expansion agents. Through a composite expansion system with a dual-activity gradient and a dual-peak particle size distribution, it works in synergy with the early-stage expansion of ettringite in cement hydration to form a three-level gradient expansion system covering the entire age of the stone body. This effectively avoids defects such as selective adsorption and uneven coating, early-stage rapid expansion and late-stage delayed expansion, and achieves gapless shrinkage compensation throughout the entire age. It can prevent the stone body from separating from the surrounding rock interface and the generation of internal microcracks, and significantly improve the long-term volume stability, crack resistance and service performance of the reinforcement material. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the embodiments.

[0030] Unless otherwise specified, the raw materials used in the preparation examples, embodiments, and comparative examples of this application are all commercially available.

[0031] Preparation Examples 1-6: pH-Metal Ion Dual-Response Composite Functional Powders Preparation Example 1 This preparation example discloses a method for preparing a pH-metal ion dual-responsive composite functional powder, which specifically includes the following steps: (1) Add 1 kg of acrylic acid-acrylamide copolymer to 15.67 kg of deionized water and stir at 300 r / min for 30 min at 25 °C until completely dissolved; add 0.12 kg of dopamine hydrochloride and stir at 300 r / min for 15 min at 25 °C until completely dissolved; add 0.1 mol / L hydrochloric acid dropwise to adjust the pH of the system to 5.2 ± 0.02, add 0.15 kg of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.05 kg of N-hydroxysuccinimide, and stir at 200 r / min for 15 min to activate; purge the air in the reactor by introducing nitrogen gas (flow rate 50 mL / min) for 10 min, and maintain nitrogen Under nitrogen protection, the reaction was carried out at 25℃ and 150 r / min for 15 h to obtain a reaction solution. The preparation method of the acrylic acid-acrylamide copolymer was as follows: 250 g of sodium acrylate and 750 g of acrylamide were dissolved in 3000 g of deionized water, and after purging with nitrogen for 20 min to remove oxygen, the mixture was stirred until completely dissolved, and the pH of the system was adjusted to 7. The temperature was raised to 40℃ and nitrogen was continuously purged for protection. 0.5 g of potassium persulfate was dissolved in 25 mL of deionized water, and 0.2 g of sodium bisulfite was dissolved in 25 mL of deionized water. These were added dropwise to the above system simultaneously, and the reaction was kept at this temperature for 6 h to obtain a colloid. The colloid was sheared into 1-2 cm particles, vacuum dried at 80℃ for 12 h, pulverized, and passed through an 80 mesh sieve to obtain powdered acrylic acid-acrylamide copolymer. (2) The reaction solution was transferred to an ultrafiltration system (polyethersulfone ultrafiltration membrane, membrane area 0.1 m², molecular weight cutoff 100,000 Da), and ultrafiltration dialysis was performed at an operating pressure of 0.2 MPa and a temperature of 25 °C. The dialysis solution (deionized water) was replaced every 30 min, and dialysis was continued until the conductivity of the dialysis solution was ≤10 μS / cm (dialysis was performed 7 times in total) to obtain the purified polymer mother liquor. 3.5 g of KH-570 silane coupling agent was added to the mother liquor and stirred at 200 r / min at 25 °C for 20 min until uniform. The mixture was transferred to a spray dryer, and the inlet air temperature was set to 180 °C, the outlet air temperature to 80 °C, the feed rate to 5 mL / min, and the atomizer speed to 25000 r / min. The powder was collected using a cyclone separator. The dried powder was collected and passed through a 200-mesh standard sieve to obtain pH-metal ion dual-response composite functional powder.

[0032] Preparation Example 2 This preparation example is basically the same as Preparation Example 1, except that in step (1), 1 kg of acrylic acid-acrylamide copolymer (prepared by the same method as Preparation Example 1) is added to 15.67 kg of deionized water and stirred at 300 r / min for 30 min at 25 °C until completely dissolved; 0.12 kg of dopamine hydrochloride and 0.03 kg of [unclear text - possibly a type of chemical compound] are added. 2-Acrylamido-2-methylpropanesulfonic acid was stirred at 25°C and 300 rpm for 15 min until completely dissolved. 0.1 mol / L hydrochloric acid was added dropwise to adjust the pH of the system to 5.2 ± 0.02. 0.15 kg of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.05 kg of N-hydroxysuccinimide were added, and the mixture was stirred at 200 rpm for 15 min to activate it. Nitrogen gas (flow rate 50 mL / min) was introduced to purge the air from the reactor (for 10 min). The reactor was kept under nitrogen protection and reacted at 25°C and 150 rpm for 15 h to obtain the reaction solution.

[0033] Preparation Example 3 This preparation example is basically the same as Preparation Example 1, except that in step (2), the reaction solution is transferred to an ultrafiltration system (polyethersulfone ultrafiltration membrane, membrane area 0.1 m²). 2 The polymer was subjected to ultrafiltration dialysis at an operating pressure of 0.2 MPa and a temperature of 25 °C, with the dialysate (deionized water) replaced every 30 min. Dialysis was continued until the conductivity of the dialysate was ≤10 μS / cm (a total of 7 dialysis cycles) to obtain a purified polymer mother liquor. 2 kg of composite aluminosilicate micro powder (pre-mixed with 1.1 kg of quartz micro powder, 0.6 kg of calcined kaolin, and 0.3 kg of diatomaceous earth) was added to the mother liquor and stirred at 200 r / min for 30 min at 25 °C until homogeneous. The mixture was transferred to a spray dryer with an inlet air temperature of 180 °C, an outlet air temperature of 80 °C, a feed rate of 50 L / h, and an atomizer speed of 15000 r / min. A cyclone separator was used to collect the powder. The dried powder was collected and passed through a 200-mesh standard sieve to obtain a pH-metal ion dual-response composite functional powder.

[0034] Preparation Example 4 This preparation example is basically the same as Preparation Example 1, except that in step (2), the reaction solution is transferred to an ultrafiltration system (polyethersulfone ultrafiltration membrane, membrane area 0.1 m²). 2The molecular weight cutoff was 100,000 Da. Ultrafiltration dialysis was performed at an operating pressure of 0.2 MPa and a temperature of 25 °C. The dialysate (deionized water) was replaced every 30 min, and dialysis was continued until the conductivity of the dialysate was ≤10 μS / cm (a total of 7 dialysis cycles) to obtain the purified polymer mother liquor. 2 kg of composite aluminosilicate micro powder (prepared by uniformly mixing 1.1 kg of quartz micro powder, 0.6 kg of calcined kaolin, and 0.3 kg of diatomaceous earth) was added to the mother liquor and stirred at a low speed of 200 r / min for 10 min. The system was then heated to 52℃, and 0.1 mol / L sodium hydroxide solution was added dropwise to adjust the pH of the system to 6.2 ± 0.05. The mixture was then stirred at a constant temperature and high speed of 1000 r / min for 30 min. The mixture was then transferred to a spray dryer, and the inlet air temperature was set to 180℃, the outlet air temperature to 80℃, the feed rate to 50 L / h, and the atomizer speed to 15000 r / min. The powder was collected using a cyclone separator. The dried powder was collected and passed through a 200-mesh standard sieve to obtain pH-metal ion dual-response composite functional powder.

[0035] Preparation Example 5 This preparation example discloses a method for preparing a pH-metal ion dual-responsive composite functional powder, which specifically includes the following steps: (1) 1 kg of acrylic acid-acrylamide copolymer (preparation method is the same as in preparation example 1) was added to 15.67 kg of deionized water and stirred at 300 r / min for 30 min at 25 °C until completely dissolved; 80 g of dopamine hydrochloride and 20 g of 2-acrylamido-2-methylpropanesulfonic acid were added and stirred at 300 r / min at 25 °C for 15 min until completely dissolved; 0.1 mol / L hydrochloric acid was added dropwise to adjust the pH of the system to 5.0 ± 0.02; 0.12 kg of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.04 kg of N-hydroxysuccinimide were added and stirred at 200 r / min for 15 min to activate; nitrogen gas (flow rate 50 mL / min) was introduced to purge the air in the reactor (for 10 min) and nitrogen protection was maintained. The reaction was carried out at 150 r / min at 25 °C for 12 h to obtain the reaction solution; (2) Transfer the reaction solution to an ultrafiltration system (polyethersulfone ultrafiltration membrane, membrane area 0.1 m²). 2The polymer (with a molecular weight cutoff of 100,000 Da) was subjected to ultrafiltration dialysis at an operating pressure of 0.2 MPa and a temperature of 25 °C. The dialysate (deionized water) was replaced every 30 minutes, and dialysis was continued until the conductivity of the dialysate was ≤10 μS / cm (a total of 7 dialysis cycles) to obtain a purified polymer mother liquor. 1.5 kg of composite aluminosilicate micro powder (prepared by uniformly mixing 0.75 kg of quartz micro powder, 0.525 kg of calcined kaolin, and 0.225 kg of diatomaceous earth) was added to the mother liquor, and the mixture was first stirred at a low speed of 150 r / min for 10 minutes. min; then heat the system to 50℃, add 0.1mol / L sodium hydroxide solution dropwise to adjust the pH of the system to 6.0±0.05, switch to 800r / min speed and stir at a constant temperature for 30min; transfer the mixture to a spray dryer, set the inlet air temperature to 180℃, the outlet air temperature to 80℃, the feed rate to 50L / h, and the atomizer speed to 15000r / min, and use a cyclone separator to collect the powder; collect the dried powder and pass it through a 200-mesh standard sieve to obtain pH-metal ion dual-response composite functional powder.

[0036] Preparation Example 6 This preparation example discloses a method for preparing a pH-metal ion dual-responsive composite functional powder, which specifically includes the following steps: (1) 1 kg of acrylic acid-acrylamide copolymer (preparation method is the same as in preparation example 1) was added to 15.67 kg of deionized water and stirred at 300 r / min at 25 °C for 30 min until completely dissolved; 0.15 kg of dopamine hydrochloride and 40 g of 2-acrylamido-2-methylpropanesulfonic acid were added and stirred at 300 r / min at 25 °C for 15 min until completely dissolved; 0.1 mol / L hydrochloric acid was added dropwise to adjust the pH of the system to 5.5 ± 0.02; 0.18 kg of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.06 kg of N-hydroxysuccinimide were added and stirred at 200 r / min for 15 min to activate; nitrogen gas (flow rate 50 mL / min) was introduced to purge the air in the reactor (for 10 min) and nitrogen protection was maintained. The reaction was carried out at 25 °C at 150 r / min for 18 h to obtain the reaction solution; (2) Transfer the reaction solution to an ultrafiltration system (polyethersulfone ultrafiltration membrane, membrane area 0.1 m²). 2The polymer (with a molecular weight cutoff of 100,000 Da) was subjected to ultrafiltration dialysis at an operating pressure of 0.2 MPa and a temperature of 25 °C. The dialysate (deionized water) was replaced every 30 minutes, and dialysis was continued until the conductivity of the dialysate was ≤10 μS / cm (a total of 7 dialysis cycles) to obtain a purified polymer mother liquor. 3 kg of composite aluminosilicate powder (prepared by uniformly mixing 1.8 kg of quartz powder, 0.75 kg of calcined kaolin, and 0.45 kg of diatomaceous earth) was added to the mother liquor, and the mixture was first stirred at a low speed of 250 r / min for 10 minutes. The system was then heated to 55℃, and 0.1 mol / L sodium hydroxide solution was added dropwise to adjust the pH of the system to 6.5 ± 0.05. The mixture was then stirred at a constant temperature and high speed of 1200 r / min for 30 min. The mixture was then transferred to a spray dryer, with the inlet air temperature set to 180℃, the outlet air temperature to 80℃, the feed rate to 50 L / h, and the atomizer speed to 15000 r / min. A cyclone separator was used to collect the powder. The dried powder was collected and passed through a 200-mesh standard sieve to obtain a pH-metal ion dual-response composite functional powder.

[0037] Preparation Examples 7-9: Magnesium Oxide Micro-Expansion Agent Preparation Example 7 This preparation example discloses a method for preparing a magnesium oxide micro-expansion agent, specifically including the following steps: 0.6 kg of magnesium oxide expansive agent for M-type concrete with a particle size of 8-15 μm was added to a constant-temperature stirred reactor and heated to 90°C. 0.21 kg of 0.8 wt% calcium stearate ethanol solution was added. After solid-liquid mixing, the mixture was continuously stirred at a constant temperature at 200 r / min until the material changed from a wet and viscous state to a loose and dry powder state. The difference in material mass between two weighings 10 min apart was no more than 0.2%. The mixture was then allowed to cool naturally to room temperature and passed through a 200-mesh sieve to obtain calcium stearate-coated magnesium oxide expansive agent for M-type concrete. 0.4 kg of S-type concrete magnesium oxide expansive agent with a particle size of 15-25 μm was added to a constant-temperature stirred reactor and heated to 90°C. 0.14 kg of 0.8 wt% calcium stearate ethanol solution was added. After solid-liquid mixing, the mixture was continuously stirred at a constant temperature at 200 r / min until the material changed from a wet and viscous state to a loose and dry powder state. The difference in material mass between two weighings 10 min apart was no more than 0.2%. The mixture was then allowed to cool naturally to room temperature and passed through a 200-mesh sieve to obtain calcium stearate-coated magnesium oxide expansive agent for S-type concrete. The above-mentioned calcium stearate-coated magnesium oxide expansion agent for M-type concrete and calcium stearate-coated magnesium oxide expansion agent for S-type concrete are stirred at 30 r / min for 5 min to obtain magnesium oxide micro-expansion agent.

[0038] Preparation Example 8 This preparation example discloses a method for preparing a magnesium oxide micro-expansion agent, specifically including the following steps: 0.65 kg of magnesium oxide expansive agent for M-type concrete with a particle size of 8-15 μm was added to a constant-temperature stirred reactor and heated to 100°C. 0.228 kg of 1.15 wt% calcium stearate ethanol solution was added. After solid-liquid mixing, the mixture was continuously stirred at a constant temperature at 200 r / min until the material changed from a wet and viscous state to a loose and dry powder state. The difference in material mass between two weighings 10 min apart was no more than 0.2%. The mixture was then allowed to cool naturally to room temperature and passed through a 200-mesh sieve to obtain calcium stearate-coated magnesium oxide expansive agent for M-type concrete. 0.35 kg of S-type concrete magnesium oxide expansive agent with a particle size of 15-25 μm was added to a constant-temperature stirred reactor and heated to 100°C. 0.123 kg of 1.15 wt% calcium stearate ethanol solution was added. After solid-liquid mixing, the mixture was continuously stirred at a constant temperature at 200 r / min until the material changed from a wet and viscous state to a loose and dry powder state. The difference in material mass between two weighings at 10 min intervals was no more than 0.2%. The mixture was then allowed to cool naturally to room temperature and passed through a 200-mesh sieve to obtain calcium stearate-coated magnesium oxide expansive agent for S-type concrete. The above-mentioned calcium stearate-coated magnesium oxide expansion agent for M-type concrete and calcium stearate-coated magnesium oxide expansion agent for S-type concrete are stirred at 30 r / min for 5 min to obtain magnesium oxide micro-expansion agent.

[0039] Preparation Example 9 This preparation example discloses a method for preparing a magnesium oxide micro-expansion agent, specifically including the following steps: 0.7 kg of magnesium oxide expansive agent for M-type concrete with a particle size of 8-15 μm was added to a constant-temperature stirred reactor and heated to 110°C. 0.245 kg of 1.5 wt% calcium stearate ethanol solution was added. After solid-liquid mixing, the mixture was continuously stirred at a constant temperature at 200 r / min until the material changed from a wet and viscous state to a loose and dry powder state. The difference in material mass between two weighings at 10 min intervals was no more than 0.2%. The mixture was then allowed to cool naturally to room temperature and passed through a 200-mesh sieve to obtain calcium stearate-coated magnesium oxide expansive agent for M-type concrete. 0.3 kg of S-type concrete magnesium oxide expansive agent with a particle size of 15-25 μm was added to a constant temperature stirred reactor and heated to 110℃. 0.105 kg of 1.5 wt% calcium stearate ethanol solution was added. After solid-liquid mixing, the mixture was stirred continuously at a constant temperature at 200 r / min until the material changed from a wet and viscous state to a loose and dry powder state. The difference in material mass between two weighings at 10 min intervals was no more than 0.2%. The mixture was then allowed to cool naturally to room temperature and passed through a 200-mesh sieve to obtain calcium stearate-coated magnesium oxide expansive agent for S-type concrete. The above-mentioned calcium stearate-coated magnesium oxide expansion agent for M-type concrete and calcium stearate-coated magnesium oxide expansion agent for S-type concrete are stirred at 30 r / min for 5 min to obtain magnesium oxide micro-expansion agent.

[0040] Example 1 This embodiment provides a method for preparing an inorganic reinforcement material for mining. 52.5 kg of sulfoaluminate cement, 10 kg of silica fume, 7.5 kg of gypsum dihydrate, 2 kg of lime, 1.75 kg of lithium sulfate, 3 kg of magnesium oxide micro-expansion agent (obtained in Preparation Example 7), 0.85 kg of polycarboxylate dispersant, 0.45 kg of hydroxypropyl methylcellulose ether, and 4 kg of metakaolin are stirred at 22 r / min for 3 min. Then, 1.75 kg of pH-metal ion dual-response composite functional powder (obtained in Preparation Example 1) is added, and the mixture is stirred at 40 r / min for 5 min to obtain the inorganic reinforcement material for mining.

[0041] Example 2 This embodiment is basically the same as Example 1, except that the pH-metal ion dual-response composite functional powder is the one obtained in Preparation Example 2.

[0042] Example 3 This embodiment is basically the same as Example 1, except that the pH-metal ion dual-response composite functional powder is the one obtained in Preparation Example 3.

[0043] Example 4 This embodiment is basically the same as Example 1, except that the pH-metal ion dual-response composite functional powder is the one obtained in Preparation Example 4.

[0044] Example 5 This embodiment provides a method for preparing an inorganic reinforcement material for mining. 45 kg of sulfoaluminate cement, 5 kg of silica fume, 5 kg of gypsum dihydrate, 1 kg of lime, 0.5 kg of lithium sulfate, 1 kg of magnesium oxide micro-expansion agent (obtained in Preparation Example 8), 0.2 kg of polycarboxylate dispersant, 0.1 kg of hydroxypropyl methylcellulose ether, and 2 kg of metakaolin are stirred at 18 r / min for 3 min. Then, 1 kg of pH-metal ion dual-response composite functional powder (obtained in Preparation Example 5) is added, and the mixture is stirred at 35 r / min for 5 min to obtain the inorganic reinforcement material for mining.

[0045] Example 6 This embodiment provides a method for preparing an inorganic reinforcement material for mining. 60 kg of sulfoaluminate cement, 15 kg of silica fume, 10 kg of gypsum dihydrate, 3 kg of lime, 3 kg of lithium sulfate, 5 kg of magnesium oxide micro-expansion agent (obtained in Preparation Example 9), 1.5 kg of polycarboxylate dispersant, 0.8 kg of hydroxypropyl methylcellulose ether, and 6 kg of metakaolin are stirred at 25 r / min for 3 min. Then, 2.5 kg of pH-metal ion dual-response composite functional powder (obtained in Preparation Example 6) is added, and the mixture is stirred at 45 r / min for 5 min to obtain the inorganic reinforcement material for mining.

[0046] Comparative Example 1 This comparative example provides a method for preparing an inorganic reinforcing material for mining. 52.5 kg of sulfoaluminate cement, 10 kg of silica fume, 7.5 kg of gypsum dihydrate, 2 kg of lime, 1.75 kg of lithium sulfate, 3 kg of magnesium oxide micro-expansion agent (obtained from Preparation Example 7), 0.85 kg of polycarboxylate dispersant, 0.45 kg of hydroxypropyl methylcellulose ether, and 4 kg of metakaolin are stirred at 22 r / min for 3 min to obtain the inorganic reinforcing material for mining.

[0047] Comparative Example 2 This comparative example provides a method for preparing an inorganic reinforcement material for mining. 52.5 kg of sulfoaluminate cement, 10 kg of silica fume, 7.5 kg of gypsum dihydrate, 2 kg of lime, 1.75 kg of lithium sulfate, 3 kg of magnesium oxide micro-expansion agent (obtained in Preparation Example 7), 0.85 kg of polycarboxylate dispersant, 0.45 kg of hydroxypropyl methylcellulose ether, and 4 kg of metakaolin are stirred at 22 r / min for 3 min. Then, 1.75 kg of functional powder is added, and the mixture is stirred at 40 r / min for 5 min to obtain the inorganic reinforcement material for mining. The preparation method of the functional powder is as follows: 0.5g KH-570 is dissolved in 3kg anhydrous ethanol to prepare a diluent. 100kg of acrylic acid-acrylamide copolymer with a molecular weight of 3 million Da is heated to 65℃ and stirred at 1500r / min to fluidize the powder. The diluent is atomized and sprayed onto the powder at a speed of 0.5kg / min. The mixture is then kept warm and stirred for 12min. Subsequently, it is vacuum cured at 75℃ and -0.08MPa for 1.5h. After cooling to room temperature, it is passed through a 200-mesh sieve to obtain the silane-modified acrylic acid-acrylamide copolymer.

[0048] Comparative Example 3 This comparative example provides a method for preparing an inorganic reinforcing material for mining. 52.5 kg of sulfoaluminate cement, 10 kg of silica fume, 7.5 kg of dihydrate gypsum, 2 kg of lime, 1.75 kg of lithium sulfate, 3 kg of magnesium oxide micro-expansion agent (obtained in Preparation Example 7), 0.85 kg of polycarboxylate dispersant, 0.45 kg of hydroxypropyl methylcellulose ether, and 4 kg of metakaolin are stirred at 22 r / min for 3 min. Then, 1.75 kg of functional powder is added, and the mixture is stirred at 40 r / min for 5 min. n, to obtain an inorganic reinforcing material for mining; wherein, the preparation method of the functional powder is as follows: 10g KH-570 is dissolved in 50g anhydrous ethanol to prepare a diluent, 1kg dopamine hydrochloride is heated to 60℃, and under high-speed stirring at 1500r / min, the diluent is uniformly atomized and sprayed into the dopamine hydrochloride within 2min, and the temperature is maintained and stirred for 10min; then, it is vacuum cured at 80℃ and -0.08MPa for 2h, cooled to room temperature and passed through a 200-mesh sieve to obtain silane-modified polydopamine hydrochloride.

[0049] Comparative Example 4 This comparative example provides a method for preparing an inorganic reinforcing material for mining. 52.5 kg of sulfoaluminate cement, 10 kg of silica fume, 7.5 kg of gypsum dihydrate, 2 kg of lime, 1.75 kg of lithium sulfate, 3 kg of magnesium oxide micro-expansion agent (obtained in Preparation Example 7), 0.85 kg of polycarboxylate dispersant, 0.45 kg of hydroxypropyl methylcellulose ether, and 4 kg of metakaolin are stirred at 22 r / min for 3 min. Then, 1.75 kg of functional powder is added, and the mixture is stirred at 40 r / min for 5 min to obtain the inorganic reinforcing material for mining. The functional powder is prepared by stirring 1 kg of silane-modified acrylic-acrylamide copolymer (preparation method as in Comparative Example 2) and 0.12 kg of silane-modified polydopamine hydrochloride (preparation method as in Comparative Example 3) at 30 r / min for 5 min to obtain the functional powder.

[0050] Performance testing The performance of the inorganic reinforcing materials for mining prepared in Examples 1-6 and Comparative Examples 1-4 was tested according to the following method. All samples were mixed with water at a water-cement ratio of 0.4 to form a slurry. The mixing regime was to first mix at a speed of 60 r / min for 60 s, and then mix at a speed of 120 r / min for 120 s.

[0051] 1. Basic physical and mechanical properties (1) Setting time: Referring to GB / T1346-2011 "Test methods for standard consistency water consumption, setting time and soundness of cement", the initial setting time and final setting time of the reinforcing grout were determined by the Vicat method. The test results are recorded in Table 1.

[0052] (2) Compressive strength: Refer to GB / T17671-2021 "Test method for strength of cement mortar (ISO method)" and pour the grout into a 40mm×40mm×40mm cube mold. After standard curing to the specified age (1d, 3d, 28d), the compressive strength is measured and the test results are recorded in Table 1.

[0053] 2. Dynamic water anti-dispersion performance (1) Underwater anti-dispersion (suspended solids content): Refer to DL / T5117-2021 "Test Procedure for Underwater Non-dispersible Concrete", prepare simulated mine water (pH=5.0, containing Fe) 3+ 80mg / L, Al 3+ 50mg / L, Ca 2+ 200 mg / L, SO4 2- 100g of slurry was dropped freely into 500mL of simulated mine water (drop distance 50cm). After standing for 30min, the supernatant was taken to determine the suspended solids (SS) content. The lower the suspended solids content, the better the anti-dispersion property of the dynamic water. The test results are recorded in Table 2.

[0054] (2) Stasis rate of dynamic water: The self-closing water flushing device (flow rate 0.3m / s, mine water pH=5.0) was used to cure 200g of slurry under dynamic water flushing for 24h. The stasis was rinsed with clean water and dried to constant weight. Stasis rate = dry weight of stasis / dry mass of slurry × 100%. The test results are recorded in Table 2.

[0055] (3) High mineralization tolerance: The SO4 content of the above simulated mine water 2- Concentration increased to 8000 mg / L, Cl - High-mineralization mine water with a concentration of 5000 mg / L was prepared, and the suspended solids content in the high-mineralization mine water was determined according to the above method (1). The test results are recorded in Table 2.

[0056] 3. Reinforcement performance (1) Bond strength with rock interface: Referring to GB / T50448-2015 "Technical Specification for Application of Cement-based Grouting Materials", the grout was injected between two standard sandstone test blocks (50mm×50mm×20mm) to form a 5mm grout layer. After standard curing for 28 days, the interface bond strength was determined by splitting tensile test. The test results are recorded in Table 3.

[0057] (2) Restricted expansion rate: Refer to JC / T313-2009 "Test method for expansion rate of expansive cement", and determine the restricted expansion rate after curing in water for 28 days. The test results are recorded in Table 3.

[0058] Table 1. Basic physical and mechanical performance test data of Examples 1-6 and Comparative Examples 1-4

[0059] Table 2. Test data on the anti-dispersion performance of Examples 1-6 and Comparative Examples 1-4 in dynamic water flow.

[0060] Table 3. Test data on reinforcement performance and storage stability of Examples 1-6 and Comparative Examples 1-4.

[0061] Referring to Tables 1-3, and combining Example 1 and Comparative Example 1, it can be seen that Example 1, compared with Comparative Example 1 without the addition of dual-response functional powder, shows a significant improvement in overall mechanical strength. The setting time is slightly prolonged, but it still meets the needs of rapid underground construction. The slurry fluidity remains good and does not affect on-site pumping operations. The anti-dispersion ability in mine water environment is greatly improved, the amount of impurities precipitated in water is significantly reduced, and the integrity of stone formation is better under dynamic water conditions. At the same time, it still has better anti-dispersion stability in the face of complex mine water quality with high salt and high sulfate. The interface bonding with the surrounding rock mass is stronger, and the interface bonding performance is better. Relying on the composite expansion component, a gradient micro-expansion effect can be stably achieved, effectively compensating for the hardening shrinkage defect of the slurry. Only the fluidity retention effect of the powder is slightly reduced during long-term storage. The overall comprehensive application performance is far superior to pure inorganic matrix reinforcement materials, and it is more suitable for the grouting and reinforcement of fractured surrounding rock in deep mines with dynamic water.

[0062] Referring to Tables 1-3, and in conjunction with Example 1 and Comparative Examples 2-4, it can be seen that compared to silane-modified polymer powder, silane-modified dopamine powder, and functional powders physically compounded from both, the dual-response composite functional powder prepared by molecular-level covalent grafting in this application can further enhance the mechanical strength and interfacial bonding ability of inorganic reinforcing materials at all ages while ensuring normal setting rhythm and construction flow performance. It leverages the integrated molecular structure to achieve synergistic effects of pH response and metal ion complexation, significantly optimizing the anti-dispersion ability and water-flow stone formation effect of the slurry in different pH levels and high-mineralization mine water. Performance retention is even more outstanding in high-salt complex water environments. Furthermore, the inorganic coating modification effectively improves the compatibility of functional components with the cementitious substrate, enhancing the long-term storage stability of the product. This fully demonstrates the irreplaceable synergistic advantages of the chemically grafted integrated structure compared to simple surface modification and physical blending.

[0063] Referring to Tables 1-3 and combining Examples 1 and 2, it can be seen that, compared with Example 1, Example 2 introduces 2-acrylamido-2-methylpropanesulfonic acid during the preparation of dual-response functional powder. Without significantly changing the slurry's setting rhythm and pumping flow performance, it further improves the mechanical strength of the reinforcement material at all ages and its interfacial bonding ability with the rock matrix. At the same time, it significantly enhances the slurry's anti-dispersion adaptability in different acid and alkaline environments and high-mineralization water bodies, effectively reduces the shielding interference of high-salt ions on the responsive functional sites, and has a better adaptive regulation effect in the water environment. The overall service stability and application range under complex working conditions are further broadened, and the comprehensive performance of the material is more excellent.

[0064] Referring to Tables 1-3 and combining Examples 1 and 3, it can be seen that, compared with Example 1, Example 3 introduces composite aluminosilicate micro powder for modification during the functional powder preparation stage. While basically maintaining the slurry's coagulation characteristics and construction flow properties, it effectively improves the overall mechanical strength and interfacial bonding effect of the reinforcement material, optimizes the interfacial compatibility between the organic functional powder and the inorganic cementing system, further improves the slurry's anti-dispersion performance in flowing water and different water quality environments, and enhances the powder's own moisture resistance, thereby improving the long-term storage stability of the reinforcement material and making its overall engineering application stability more advantageous.

[0065] Referring to Tables 1-3 and combining Examples 1 and 4, it can be seen that, compared with Example 1, Example 4 further modifies the interface by adjusting the system temperature and pH based on the addition of composite aluminosilicate micro powder. This makes the inorganic coating layer and the polymer matrix more firmly bonded, which not only maintains the normal setting characteristics and flowability of the slurry, but also further improves the mechanical strength of the reinforcement material and the bonding effect of the rock mass interface. It also enhances the anti-dispersion ability and working condition adaptability of the slurry in water bodies with different pH levels and in high mineralization environments. The functional components are not easy to fall off and fail during the mixing and pumping process. The overall comprehensive performance and long-term stability of the material are significantly optimized.

[0066] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A mining inorganic reinforcement material, characterized in that, The raw materials include the following parts by weight: 45-60 parts of sulfoaluminate cement, 5-15 parts of silica fume, 5-10 parts of gypsum dihydrate, 1-3 parts of lime, 0.5-3 parts of lithium sulfate, 1-5 parts of magnesium oxide micro-expansion agent, 0.2-1.5 parts of polycarboxylate dispersant, 0.1-0.8 parts of hydroxypropyl methylcellulose ether, 2-6 parts of metakaolin, and 1-2.5 parts of pH-metal ion dual-responsive composite functional powder; The pH-metal ion dual-responsive composite functional powder is prepared by chemically grafting a complex unit containing a catechol structure onto a pH-responsive polymer.

2. A method for preparing an inorganic reinforcing material for mining according to claim 1, characterized in that, Includes the following steps: Sulfoaluminate cement, silica fume, gypsum dihydrate, lime, lithium sulfate, magnesium oxide micro-expansion agent, polycarboxylate dispersant, hydroxypropyl methylcellulose ether, and metakaolin are stirred at 18-25 r / min for 3 min. Then, pH-metal ion dual-responsive composite functional powder is added, and the mixture is stirred at 35-45 r / min for 5 min to obtain an inorganic reinforcing material for mining.

3. The method for preparing the inorganic reinforcing material for mining according to claim 2, characterized in that, The magnesium oxide micro-expansion agent is prepared by mixing the magnesium oxide expansion agent for M-type concrete and the magnesium oxide expansion agent for S-type concrete with a 0.8-1.5wt% calcium stearate ethanol solution at 90-110℃, stirring, and then mixing the resulting products.

4. The method for preparing the inorganic reinforcing material for mining according to claim 3, characterized in that, The mass ratio of the magnesium oxide expansive agent for M-type concrete to the magnesium oxide expansive agent for S-type concrete is 6-7:3-4; The particle size of the magnesium oxide expansive agent for M-type concrete is 8-15μm, and the particle size of the magnesium oxide expansive agent for S-type concrete is 15-25μm.

5. The method for preparing the inorganic reinforcing material for mining according to claim 2, characterized in that, The preparation method of the pH-metal ion dual-responsive composite functional powder includes the following steps: Step 1: Dissolve 100 parts by weight of acrylic acid-acrylamide copolymer in deionized water to form a 6 wt% aqueous solution. Then add 8-15 parts by weight of catechol functional monomers, stir to dissolve, adjust the pH of the system to 5-5.5, add 12-18 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-6 parts by weight of N-hydroxysuccinimide, and activate for 15 min. Under nitrogen protection, react at 25°C for 12-18 h to obtain the reaction solution. Step 2: The reaction solution is subjected to ultrafiltration dialysis to obtain the mother liquor. 0.2-0.5 parts by weight of KH-570 silane coupling agent is added to the mother liquor, stirred evenly, spray dried, and sieved to obtain the pH-metal ion dual-response composite functional powder.

6. The method for preparing the inorganic reinforcing material for mining according to claim 5, characterized in that, Step 1: Dissolve 100 parts by weight of acrylic acid-acrylamide copolymer in deionized water to form a 6 wt% aqueous solution. Then add 8-15 parts by weight of catechol functional monomer and 2-4 parts by weight of 2-acrylamido-2-methylpropanesulfonic acid. Stir to dissolve and adjust the pH of the system to 5-5.

5. Then add 12-18 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-6 parts by weight of N-hydroxysuccinimide. Activate for 15 min. Under nitrogen protection, react at 25°C for 12-18 h to obtain the reaction solution.

7. The method for preparing the inorganic reinforcing material for mining according to claim 6, characterized in that, The catechol functional monomers are one or more of dopamine hydrochloride, gallic acid, and 3,4-dihydroxyphenylpropionic acid.

8. The method for preparing the inorganic reinforcing material for mining according to claim 5, characterized in that, Step 2: The reaction solution is subjected to ultrafiltration dialysis to obtain the mother liquor. 1.5-3 parts by weight of composite aluminosilicate micro powder is added to the mother liquor, stirred evenly, spray dried, and sieved to obtain the pH-metal ion dual-response composite functional powder.

9. The method for preparing the inorganic reinforcing material for mining according to claim 5, characterized in that, Step 2: The reaction solution is subjected to ultrafiltration dialysis to obtain the mother liquor. 1.5-3 parts by weight of composite aluminosilicate micro powder is added to the mother liquor. First, stir at a speed of 150-250 r / min for 10 min, then heat to 50-55℃ and adjust the pH to 6-6.

5. Stir at a speed of 800-1200 r / min for 30 min, spray dry, and sieve to obtain the pH-metal ion dual-response composite functional powder.

10. The method for preparing the inorganic reinforcing material for mining according to claim 9, characterized in that, The composite aluminosilicate powder is a mixture of quartz powder, calcined kaolin, and diatomaceous earth in a mass ratio of 50-65:25-35:15.

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