Rapid-setting, high-strength, erosion-resistant grouting material for treating runoff water in ultra-deep metal mine tunnels and its preparation method.

Abstract

This invention belongs to the field of mining engineering and building materials technology, and relates to a rapid-setting, high-strength, and erosion-resistant grouting material for the treatment of seepage water in ultra-deep metal mine roadways, and its preparation method. The grouting material, by weight, comprises: 42-52 parts ultrafine silicate cement, 23-28 parts ultrafine sulfoaluminate cement, 14-18 parts mineral powder, 3-6 parts silica fume, 1-5 parts calcined hydrotalcite, a polycarboxylate superplasticizer, and a slow-release accelerator. The slow-release accelerator uses lithium carbonate as the core material and stearic acid or a stearic acid-polymer wax composite system as the shell material, formed through melt coating. This invention achieves controllable grout setting time (initial setting approximately 30 min), high fluidity (≥40 cm), and rapid early strength development at a high temperature of 40-60℃ by constructing a synergistic effect between an ultrafine composite cementitious system and a slow-release accelerator system. Simultaneously, it significantly improves the material's resistance to chloride erosion by utilizing the ion adsorption capacity of calcined hydrotalcite and the hydrophobic structure formed by stearic acid saponification. This material is suitable for sealing water seepage in tunnels under high temperature, high salinity, and flowing water conditions.

Description

Technical Field

[0001] This invention belongs to the field of mining engineering and building materials technology, specifically relating to a fast-setting, high-strength, erosion-resistant grouting material for the treatment of seepage water in ultra-deep metal mine roadways and its preparation method. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] As mineral resource extraction progresses to deeper levels, ultra-deep metal mine tunnel engineering faces increasingly severe challenges. Deep environments are typically characterized by high geothermal temperatures (reaching 40-60℃ or even higher), high water pressure, and complex hydrogeological conditions. The surrounding rock of the tunnels often experiences high-pressure, high-flow-rate, and continuous seepage of water, which is often rich in corrosive media such as sulfates and chloride ions. These hazards not only deteriorate the working environment and threaten construction safety, but also soften the surrounding rock, reduce the durability of the support structure, and even trigger major accidents such as sudden water inrush and mine flooding.

[0004] Currently, grouting technology is mainly used to control seepage water in tunnels. However, conventional cement-based grouting materials, such as ordinary silicate cement grout, exhibit significant shortcomings in such extreme environments: long setting time, inability to quickly form a water-blocking structure, and easy dispersal and dilution by water flow; low early strength, failing to provide effective support in a timely manner; accelerated hydration at high temperatures, but often accompanied by later strength reduction and decreased durability; poor resistance to underground corrosive media, making the water-blocking effect difficult to sustain. Although sulfoaluminate cement-based materials have rapid hardening and early strength characteristics, they have significant shrinkage, high cost, and their long-term strength stability and erosion resistance still need improvement.

[0005] In addition, when using grouting technology to treat runoff, high requirements are placed on the fluidity, resistance to erosion by flowing water, and early and late strength of the grouting material. In order to achieve high early strength of the grouting material, it is generally necessary to add a quick-setting agent to the grouting material. However, under high temperature conditions, grouting materials with added quick-setting agents are prone to flash setting, which seriously affects their fluidity. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a rapid-setting, high-strength, erosion-resistant grouting material for the treatment of seepage water in ultra-deep metal mine tunnels, and its preparation method. This grouting material has a controllable setting time, high early and late strength, good fluidity, strong resistance to groundwater erosion, and active salt fixation and in-situ hydrophobic functions. It is particularly suitable for grouting materials and their preparation methods for the treatment of seepage water in ultra-deep, high-geothermal metal mine tunnels.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways, comprising the following components by weight: The mixture comprises 42-52 parts of ultrafine silicate cement, 23-28 parts of ultrafine sulfoaluminate cement, 14-18 parts of mineral powder, 3-6 parts of silica fume, 1-5 parts of calcined hydrotalcite (CLDH), a water-reducing agent, and a slow-release accelerator; the shell material of the slow-release accelerator is stearic acid, polymer wax, or a compound system of the two, and the core material is selected from at least one of lithium carbonate, lithium sulfate, or sodium aluminate.

[0008] Secondly, the present invention provides a method for preparing the rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways, comprising the following steps: Mix the various components of the grouting material in the specified proportions to obtain the mixed dry powder.

[0009] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows: By controlling the particle size distribution (D) of the composite powder 10 ≤1.5μm, D 50 For, 4.5μm-5.5μm, D 90 (≤12μm), using submicron-sized silica fume to fill the voids in cement particles to release free water, achieving a flowability of ≥40cm with low water-reducing agent dosage, ensuring the injectability of complex cracks.

[0010] Calcined hydrotalcite (CLDH) significantly reduces chloride ion permeability. On one hand, it has a significant filling effect, which can optimize the internal structure of the stone, reduce porosity and average pore size, decrease the number of harmful pores, and improve the density of the stone. On the other hand, calcined hydrotalcite adsorbs and solidifies a large number of chloride ions during the structural restoration process, reducing the chloride ion content in the pore fluid, thereby reducing the permeability coefficient and significantly improving the material's impermeability.

[0011] A composite cementitious system of ultrafine silicate cement and ultrafine sulfoaluminate cement, supplemented with a slow-release accelerator, achieved rapid setting and hardening (initial setting approximately 30 minutes, final setting approximately 60 minutes). The slow-release accelerator forms a physical barrier layer through shell coating, delaying the release of lithium carbonate in the early stages of grouting and maintaining good fluidity of the grout. Under high-temperature and high-alkali conditions, stearic acid undergoes saponification to generate calcium stearate, simultaneously disrupting the coating structure and allowing the core material to be released gradually, thus enabling controllable adjustment of setting time. Simultaneously, saponification products deposit on the pore walls to form a hydrophobic layer, reducing water permeability; calcined hydrotalcite adsorbs chloride ions through structural reconstruction, and both synergistically improve the material's corrosion resistance. The pozzolanic effect of the active admixtures (mineral powder, silica fume) and the ultrafine particles synergistically construct a dense microstructure, giving the material excellent early strength.

[0012] Under high-temperature curing conditions of 40-60℃, the early strength development of the grouting material is significantly accelerated (e.g., the 1-day strength can reach 7.6MPa and the 3-day strength can reach 19MPa at 60℃), and there is no later strength shrinkage phenomenon, which can adapt to the high geothermal environment of ultra-deep mines.

[0013] The formula makes extensive use of industrial by-products such as mineral powder and silica fume, which improves performance while reducing costs and carbon emissions. Detailed Implementation

[0014] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0015] In a first aspect, the present invention provides a rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways, comprising the following components by weight: The composition includes 42-52 parts ultrafine silicate cement, 23-28 parts ultrafine sulfoaluminate cement, 14-18 parts mineral powder, 3-6 parts silica fume, 1-5 parts calcined hydrotalcite (CLDH), a water-reducing agent, and a slow-release accelerator. The shell material of the slow-release accelerator is stearic acid, a polymeric wax, or a mixture of both. The polymeric wax is an organic wax material with a high molecular weight, selected from one or more of Fischer-Tropsch wax, oxidized polyethylene wax, and microcrystalline wax. The number-average molecular weight of the polymeric wax is preferably 2000-6000, and the melting point is preferably 70-120℃. The aforementioned polymeric wax has good crystallinity and film-forming properties, and can form a dense coating layer on the surface of the core material, thereby effectively controlling the release rate of the accelerator. The core material of the slow-release accelerator is selected from at least one of lithium carbonate, lithium sulfate, or sodium aluminate.

[0016] The dry powder in this invention refers to a mixture of ultrafine silicate cement, ultrafine sulfoaluminate cement, mineral powder, silica fume and calcined hydrotalcite.

[0017] Ultrafine silicate cement, as the main cementitious component of grouting materials, provides basic strength and bonding ability. Its ultrafine particle characteristics (large specific surface area and small particle size) give it stronger hydration activity, enabling it to set and harden faster, forming early strength, while improving the material's density and impermeability, effectively sealing water seepage in roadways.

[0018] The synergistic effect of ultrafine sulfoaluminate cement and silicate cement further enhances the early strength development rate of the material. It also exhibits micro-expansion properties, compensating for shrinkage during cement hydration, improving the density and crack resistance of the grout, and enhancing water-stopping effectiveness. Furthermore, sulfoaluminate cement possesses good resistance to sulfate attack, making it suitable for the complex water environment of underground mines.

[0019] Mineral powder, as an active admixture, participates in the cement hydration reaction, generating products such as hydrated calcium silicate, which improves the later-stage strength and durability of the grout. Simultaneously, the incorporation of mineral powder can reduce cement usage, decrease heat of hydration, prevent cracking caused by temperature stress, and improve the workability of the material, such as fluidity and pumpability.

[0020] Silica fume has high activity, which can accelerate the cement hydration reaction, significantly improve the early and late strength of the grout, and refine the pore structure, greatly enhancing the material's impermeability and erosion resistance. The spherical particles of silica fume also act as a lubricant, improving the fluidity of the grout material and making it easier to penetrate into fine cracks.

[0021] Calcined hydrotalcite (CLDH), as a layered bimetallic hydroxide, possesses unique ion exchange and adsorption properties. It can adsorb harmful ions from the environment, reducing their corrosive effect on the grout. Simultaneously, CLDH can regulate the cement hydration process, optimize setting time and strength development, and improve material stability. Insufficient addition of calcined hydrotalcite results in insignificant active salt fixation, while excessive addition negatively impacts grout fluidity and subsequent strength.

[0022] Water-reducing agents can reduce the flocculation structure between cement particles, thereby lowering the water-cement ratio and improving the strength, density, and impermeability of the grouting material while ensuring its fluidity. Simultaneously, water-reducing agents can also improve the workability of the material, facilitating construction and increasing grouting efficiency.

[0023] Slow-release accelerators delay the release of the core material through a coating structure, thereby regulating the grout setting time. In the initial stage of grouting, the material maintains good fluidity, facilitating the full filling of cracks; as the core material is gradually released, it accelerates the cement hydration reaction, causing the grout to quickly set and harden, forming strength and effectively sealing off seepage water.

[0024] The shell material selected for the slow-release accelerator is stearic acid and high-molecular-weight paraffin. Stearic acid, a long-chain fatty acid, has excellent film-forming properties, allowing it to uniformly coat the surface of the accelerator core material, forming a dense protective film and effectively controlling the release rate of the core material. Stearic acid typically has a melting point of 56-72℃ and is solid at room temperature, stably coating the core material. During cement hydration, under high-temperature conditions, stearic acid gradually melts, releasing the core material and achieving a slow-release effect. This mechanism effectively solves the problem of flash setting and pumpability of slurry caused by conventional accelerators at high temperatures. Stearic acid is a naturally occurring fatty acid widely found in animal and vegetable oils, exhibiting good biocompatibility and environmental friendliness, and will not negatively impact the performance of cement-based materials or the environment.

[0025] Polymer waxes possess high molecular weight and good crystallinity, enabling them to form stable encapsulation structures, effectively slowing the release rate of the core material and achieving a long-term, stable sustained-release effect. Polymer waxes also have high melting points and thermal stability, maintaining a relatively dense skeletal structure during cement hydration and at high temperatures, preventing premature release of the core material and ensuring precise control of the setting-promoting effect. Furthermore, polymer waxes exhibit good chemical stability, rarely reacting with other components in the grouting material, thus maintaining the integrity of the shell material and the stability of its sustained-release performance.

[0026] In some preferred embodiments, the shell material is a compound system of stearic acid and polymer wax, with a mass ratio of stearic acid to polymer wax of 1-3:1.

[0027] Stearic acid possesses excellent film-forming properties and saponification reactivity in alkaline environments, enabling responsive release to the core material. Polymer waxes are used to improve the stability of the coating structure and regulate the release rate. The combination of these two components constructs a graded, slow-release structure, maintaining good fluidity in the initial stage of grouting and achieving rapid setting in the later stages. Compared to a single shell material system, this significantly enhances the overall performance of the slow-release accelerator. By selecting different types and molecular weights of polymer waxes, the properties of the shell material, such as melting point, hardness, and permeability, can be adjusted, thereby controlling the release rate of the core material and meeting diverse engineering requirements.

[0028] Ultrafine silicate cement and ultrafine sulfoaluminate cement, as the main cementing materials, respectively leverage the high strength of silicate cement and the early strength and micro-expansion characteristics of sulfoaluminate cement, complementing each other to ensure that the grout maintains a high strength growth rate in both the early and later stages. Mineral powder and silica fume, as active admixtures, undergo secondary reactions with cement hydration products, further optimizing the pore structure and improving the material's density and strength.

[0029] The high activity and ultrafine particle properties of silica fume can fill the pores of cement hydration products, forming a dense microstructure and improving the material's impermeability. Calcined hydrotalcite, on the other hand, removes corrosive ions from the water through ion exchange and adsorption, reducing their damage to the grout. Both silica fume and cement hydration products interact to jointly enhance the material's resistance to erosion, making it suitable for the complex water environment of underground mines.

[0030] Water-reducing agents improve the fluidity of grouting materials, making them easier to penetrate into minute cracks; slow-release accelerators precisely control the setting time, ensuring that the grouting material maintains good workability during construction, while rapidly hardening after grouting to form an effective water-blocking barrier. This synergistic effect ensures both ease of construction and timely and reliable water-blocking results.

[0031] The synergistic effect of ultrafine silicate cement, ultrafine sulfoaluminate cement and slow-release accelerator enables the grouting material to maintain good fluidity while quickly setting and hardening, forming early strength, sealing the seepage water in time, and preventing the expansion of water damage.

[0032] The interaction between silica fume, calcined hydrotalcite and cement hydration products refines the pore structure of the material, improves its density and impermeability, and enhances its resistance to erosion, ensuring that the grout can function stably for a long time in complex mining environments.

[0033] The addition of water-reducing agents improves the fluidity and pumpability of grouting materials, enabling them to be smoothly delivered to the grouting locations in ultra-deep tunnels and fully fill the cracks, ensuring the uniformity and integrity of the grouting effect.

[0034] The synergistic effect of the components enables the grouting material to adapt to the complex environment of ultra-deep mine tunnels, such as high temperature, high pressure, and high erosion. At the same time, the precise control of the slow-release accelerator ensures that the material maintains stable performance under different geological conditions, thereby improving the reliability and safety of the project.

[0035] In some embodiments, the grouting material further includes water, with a water-cement ratio of 0.9-1.1:1.

[0036] In some embodiments, the slow-release coagulant accounts for 0.4-0.6% of the total mass of the dry powder.

[0037] When the concentration is below 0.4%, the coagulation effect is insufficient; when it is above 0.6%, it may affect the initial fluidity and later strength of the slurry.

[0038] In some embodiments, the slow-release accelerator is prepared by: preheating the core material to 5-10°C below the melting point of the wall material, uniformly spraying the molten wall material into the core material under stirring, and the wall material solidifying on the surface of the core material to obtain the slow-release accelerator.

[0039] When the wall material is in a molten state, its temperature is high. If it is directly mixed with the room-temperature core material, the huge temperature difference will cause the wall material to cool and solidify rapidly, making it impossible to evenly coat the surface of the core material. This can easily lead to problems such as incomplete coating and uneven thickness. Preheating the core material can reduce the temperature difference between the two, allowing the wall material to spread and solidify more evenly on the surface of the core material, forming a complete and uniform coating layer.

[0040] Appropriate preheating temperature can activate the core material surface, which helps the molten wall material and core material to bond better, improves the strength of the coating, and reduces the possibility of wall material falling off during subsequent processing or use.

[0041] A core material at a low temperature may cause the molten wall material to cool and thicken rapidly, increasing the difficulty of stirring and mixing, and leading to uneven mixing. Preheating the core material can make the temperature of the entire system more uniform, improve the fluidity of the wall material on the surface of the core material, and make it easier to fully mix the core and wall materials through stirring, ensuring consistent product quality.

[0042] Preferably, the mass ratio of core material to wall material is 3-6:1, and more preferably 4-5:1.

[0043] Preferably, the particle size of the core material is 5-50 μm, and more preferably 10-30 μm.

[0044] Preferably, the melting point of the wall material is 65-70°C.

[0045] In some embodiments, the preparation method of the calcined hydrotalcite is as follows: hydrotalcite raw material with a magnesium-aluminum ratio of 2-3:1 is placed in a high-temperature furnace, heated to 450-550°C at a heating rate of 5-10°C / min, calcined at a constant temperature for 3-5 hours, and then taken out and cooled in a dry environment to obtain the product.

[0046] During the calcination process, the layered structure of hydrotalcite is destroyed, forming a porous composite metal oxide with a significantly increased specific surface area. This greatly enhances its adsorption capacity, improves the grouting material's resistance to underground corrosive media, and increases the durability of water plugging.

[0047] In some embodiments, the water-reducing agent is a polycarboxylate-based high-performance water-reducing agent, and the water-reducing agent accounts for 0.08-0.12% of the total mass of the dry powder.

[0048] In some embodiments, the particle size distribution of the mixed dry powder is D 10 ≤1.5μm, D 50 The thickness is 4.5μm-5.5μm, D 90 ≤12μm.

[0049] This particle size distribution is achieved through particle gradation of submicron-sized silica fume with micron-sized ultrafine cement and mineral powder. Small-sized particles precisely fill the voids formed by the accumulation of large-sized particles, releasing the previously bound free water. This significantly improves the fluidity of the slurry without increasing or only slightly increasing the amount of water-reducing agent, ensuring that the slurry can be effectively injected into fine cracks.

[0050] In some embodiments, the median particle size distribution D of the ultrafine silicate cement is... 50 The median particle size distribution D of the ultrafine sulfoaluminate cement is 5-6 μm. 50 The particle size distribution is 5-6 μm, and the ore powder is S95 grade granulated blast furnace slag powder with a median particle size distribution D. 50 The median particle size distribution D of the silica fume is 5-6 μm.50 It is 1-1.5 μm.

[0051] Preferably, the median particle size distribution D of the ultrafine silicate cement is... 50 The median particle size distribution D of the ultrafine sulfoaluminate cement is 5.405 μm. 50 The particle size distribution is 5.409 μm, and the ore powder is S95 grade granulated blast furnace slag powder with a median particle size distribution D. 50 The median particle size distribution D of the silica fume is 5.817 μm. 50 The particle size is 1.064 μm. This set of specific particle size parameters enables the construction of the most compact particle packing system, achieving the optimal flowability improvement effect.

[0052] In some embodiments, the product comprises the following components by weight: The following ingredients are used: 48-52 parts of ultrafine silicate cement, 25-28 parts of ultrafine sulfoaluminate cement, 16-18 parts of mineral powder, 4-6 parts of silica fume, 2-4 parts of calcined hydrotalcite (CLDH), 0.09-0.11% of the total dry powder mass of water-reducing agent, and 0.45-0.55% of the total dry powder mass of slow-release accelerator.

[0053] Preferably, by weight, it comprises the following components: 50 parts of ultrafine silicate cement, 27.5 parts of ultrafine sulfoaluminate cement, 17.5 parts of mineral powder, 5 parts of silica fume, 3 parts of calcined hydrotalcite (CLDH), the amount of water-reducing agent is 0.1% of the total dry powder mass, and the amount of slow-release accelerator is 0.5% of the total dry powder mass.

[0054] Secondly, the present invention provides a method for preparing the rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways, comprising the following steps: The grouting material is obtained by mixing its various components in the specified proportions.

[0055] In some embodiments, during construction, the dry powder and water are mixed at a water-cement ratio of 0.9-1.1:1 to prepare the grouting slurry. This water-cement ratio range can fully activate the water-reducing agent, ensuring that the slurry has good fluidity and injectability, while also taking into account the strength of the aggregate.

[0056] The water-cement ratio can be 1:1.

[0057] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0058] In the following embodiments, unless otherwise specified, the D of ultrafine silicate cement is... 50 The density is 5.405 μm; the D of ultrafine sulfoaluminate cement 50 The particle size is 5.409 μm; the ore powder is S95 grade granulated blast furnace slag powder, D50 It is 5.817 μm; the D of silica fume 50 The size is 1.064 μm, and the SiO2 content is ≥92%.

[0059] The preparation method of calcined hydrotalcite (CLDH) is as follows: hydrotalcite raw material with a magnesium-aluminum ratio of 2.5 is placed in a high-temperature furnace, heated to 500°C at a heating rate of 10°C / min, calcined at a constant temperature for 3 hours, and then taken out, cooled and packaged in a dry environment.

[0060] The preparation method of the slow-release coagulant is as follows: Lithium carbonate is used as the core material with an average particle size of 20 μm. Excessively large particle size will lead to uneven coating and affect the slow-release effect; excessively small particle size will easily cause agglomeration, which is not conducive to the formation of a stable coating layer. Stearic acid with a melting point of 68℃ is used as the wall material; the core material is preheated to 60℃, and the molten wall material is uniformly sprayed into the core material under high-speed stirring. After cooling and solidification, the product is obtained. The mass ratio of core material to wall material is 5:1.

[0061] The component content in all examples and comparative examples was measured based on a total dry powder mass of 100 parts (by weight), and water was added and mixed at a water-cement ratio (mass ratio of water to dry powder) of 1.0.

[0062] The specific specifications of each raw material are as described above. The magnesium-aluminum hydrotalcite was purchased from Shandong Yousuo Chemical Technology Co., Ltd. The polycarboxylate-based high-performance water-reducing agent was a powdered polycarboxylate water-reducing agent purchased from Jiangsu Guanxiang Building Materials Co., Ltd. The lithium carbonate accelerator was an industrial-grade product purchased from Henan Weiying Chemical Products Co., Ltd.

[0063] Example 1 A fast-setting, high-strength, and erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways comprises the following components by weight: 50 parts ultrafine silicate cement, 27.5 parts ultrafine sulfoaluminate cement, 17.5 parts mineral powder, 5 parts silica fume, 3 parts calcined hydrotalcite, a polycarboxylate-based high-performance water-reducing agent at a dosage of 0.1% of the total dry powder mass, and a slow-release accelerator at a dosage of 0.5% of the total dry powder mass.

[0064] During construction, the above grouting materials should be mixed evenly with water at a water-cement ratio of 1:1.

[0065] Example 2 A rapid-setting, high-strength, and erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways comprises, by weight, the following components: 48 parts ultrafine silicate cement, 26 parts ultrafine sulfoaluminate cement, 16 parts mineral powder, 5 parts silica fume, and 5 parts calcined hydrotalcite. The dosages of water-reducing agent and slow-release accelerator are the same as in Example 1.

[0066] Example 3 A rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways comprises, by weight, the following components: 52 parts ultrafine silicate cement, 28 parts ultrafine sulfoaluminate cement, 14 parts mineral powder, 4 parts silica fume, and 2 parts calcined hydrotalcite. The dosage of polycarboxylate-based high-performance water-reducing agent is 0.09% of the total dry powder mass, and the dosage of slow-release accelerator is 0.55% of the total dry powder mass.

[0067] Example 4 A rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways comprises, by weight, the following components: 45 parts ultrafine silicate cement, 25 parts ultrafine sulfoaluminate cement, 18 parts mineral powder, 6 parts silica fume, and 3 parts calcined hydrotalcite. The dosage of polycarboxylate-based high-performance water-reducing agent is 0.11% of the total dry powder mass, and the dosage of slow-release accelerator is 0.45% of the total dry powder mass.

[0068] Example 5 A rapid-setting, high-strength, and erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways comprises, by weight, the following components: 42 parts ultrafine silicate cement, 28 parts ultrafine sulfoaluminate cement, 18 parts mineral powder, 6 parts silica fume, and 5 parts calcined hydrotalcite. The dosage of polycarboxylate-based high-performance water-reducing agent is 0.08% of the total dry powder mass, and the dosage of slow-release accelerator is 0.6% of the total dry powder mass.

[0069] Example 6 A fast-setting, high-strength, and erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways comprises the following components by weight: 50 parts ultrafine silicate cement, 27.5 parts ultrafine sulfoaluminate cement, 17.5 parts mineral powder, 5 parts silica fume, 3 parts calcined hydrotalcite, a polycarboxylate-based high-performance water-reducing agent at a dosage of 0.1% of the total dry powder mass, and a slow-release accelerator at a dosage of 0.5% of the total dry powder mass.

[0070] The slow-release coagulant uses lithium carbonate as the core material, and the shell material adopts a compound system of stearic acid and polymer wax. The polymer wax is selected as microcrystalline wax with a melting point of 80°C, and the mass ratio of stearic acid to microcrystalline wax is 2:1; the mass ratio of core material to wall material is 4:1.

[0071] Comparative Example 1 The difference from Example 1 is that calcined hydrotalcite is replaced with ultrafine silicate cement, while everything else is the same as in Example 1.

[0072] Comparative Example 2 The difference from Example 1 is that the slow-release accelerator is replaced with ultrafine sulfoaluminate cement, while everything else is the same as in Example 1.

[0073] Comparative Example 3 The difference from Example 1 is that a common coagulant (lithium carbonate, uncoated) is used instead of a slow-release coagulant, with the same dosage.

[0074] Comparative Example 4 The difference from Example 1 is that the ultrafine silicate cement and ultrafine sulfoaluminate cement are replaced with ordinary PO42.5 silicate cement and ordinary sulfoaluminate cement (D). 50 (Approximately 15-20 μm), with the mass ratio of each component remaining unchanged.

[0075] Comparative Example 5 The difference from Example 1 is that the mineral powder is replaced with ultrafine silicate cement, otherwise it is the same as Example 1.

[0076] Comparative Example 6 The difference from Example 1 is that silica fume is replaced with ultrafine sulfoaluminate cement, otherwise it is the same as Example 1.

[0077] Comparative Example 7 The difference from Example 1 is that paraffin wax was used as the shell material when preparing the slow-release coagulant, otherwise it is the same as Example 1.

[0078] Comparative Example 8 The difference from Example 1 is that the ultrafine silicate cement is replaced with ultrafine sulfoaluminate cement, otherwise it is the same as Example 1.

[0079] Comparative Example 9 The difference from Example 1 is that the ultrafine sulfoaluminate cement is replaced with ultrafine silicate cement, otherwise it is the same as Example 1.

[0080] Comparative Example 10 The difference from Example 6 is that when preparing the slow-release coagulant, only microcrystalline wax with a melting point of 80°C is used as the shell material, while the other components, proportions and preparation methods are the same as in Example 6.

[0081] Performance testing conditions: The performance of the grouting materials in Examples 1-6 and Comparative Examples 1-9 was tested. Flowability was determined according to the "Method for Determination of Flowability of Cement Mortar" (GB / T 2419); setting time was determined according to the "Test Method for Standard Consistency Water Requirement, Setting Time and Soundness of Cement" (GB / T 1346); and strength was tested according to the "Test Method for Strength of Cement Mortar (ISO Method)" (GB / T17671). The compressive strength at 1 day, 3 days, and 28 days under curing conditions of 40℃ and 60℃ was tested to simulate the high geothermal environment of ultra-deep mines.

[0082] The specific method for testing salt corrosion resistance is as follows: The specimen, cured at 40℃ for 28 days, is immersed in a salt solution at 40℃ for 28 days. The salt solution composition is Cl... -The concentration was 10000 mg / L (prepared with NaCl), and the solution was changed every 7 days to maintain a stable concentration. After soaking for 28 days, the specimens were removed, and their compressive strength was tested and compared with the strength after curing at 40℃ for 28 days. The strength loss rate was calculated. The test results are shown in Table 1.

[0083] Table 1 Test Results of Examples and Comparative Examples

[0084] As can be seen from the performance comparison in Table 1, the fast-setting, high-strength, and erosion-resistant grouting material provided by this invention for the treatment of seepage water in ultra-deep metal mine roadways exhibits significantly better performance indicators than the comparative examples under extreme conditions of simulated deep high temperature and strong salt erosion.

[0085] Specifically, this manifests as follows: As shown in Table 1, the 28-day compressive strength of each embodiment of the present invention at 60℃ is higher than that at 40℃, with Example 1 reaching a strength of 55.0 MPa at 60℃. This is due to the significant high-temperature synergistic effect between the ultrafine cementitious system (ultrafine silicate cement and sulfoaluminate cement) and the active mineral admixtures (mineral powder, silica fume): deep geothermal energy accelerates the pozzolanic reaction of the ultrafine powder, inducing the hydration products to grow more uniformly and densely at the microscale. In contrast, traditional grouting materials often experience a decline in strength at temperatures exceeding 40℃, while the present invention utilizes the high-temperature environment to enhance the density of the cementitious products, solving the problem of strength stability under deep geothermal conditions.

[0086] This invention utilizes a multi-level particle size distribution design, achieving an initial flowability ≥40cm through the close packing of submicron-sized silica fume and micron-sized ultrafine components, and adding a small amount of water-reducing agent, ensuring the grout's injectability in complex and minute fissures. Simultaneously, a slow-release accelerator prepared via a melt-coating method enables controllable setting time, preventing flash setting due to high temperatures. For example, in Example 1, the initial setting time at 60℃ is stable at 30 minutes, providing ample safe construction window; and upon contact with highly alkaline water in the fissure, the coating layer slowly releases through saponification, achieving rapid sealing. This effectively solves the problem of traditional fast-setting materials easily flashing and causing pump jamming in high-temperature pipelines.

[0087] Furthermore, Example 6, which uses a shell material composed of stearic acid and polymer wax, exhibits a moderate setting time and a strength attenuation rate of only 7.7%, demonstrating superior overall performance compared to Comparative Example 10, which uses only polymer wax as its shell material (attenuation rate of 16.9%). Comparative Example 10, due to its shell material being solely polymer wax, lacks the alkaline-responsive saponification activity of stearic acid, thus failing to effectively generate a hydrophobic barrier in the micropores, resulting in insufficient corrosion resistance. Example 6, through the combination of stearic acid and polymer wax, achieves "staged slow release." In the initial stage of grouting, the polymer wax maintains the integrity of the coating structure to ensure fluidity. Later, in a highly alkaline environment, the stearic acid component preferentially responds and undergoes a saponification reaction, gradually releasing the core material and forming an in-situ hydrophobic barrier, thereby balancing good workability with long-term corrosion resistance.

[0088] The introduced calcined hydrotalcite (CLDH) exhibited significant active salt fixation and micro-filling effects. On the one hand, as an ultrafine component, CLDH optimized the internal structure of the stone, significantly reducing the number of harmful pores and the permeability coefficient. On the other hand, it actively adsorbed and solidified a large number of free chloride ions through a structural restoration process. Data in Table 1 shows that Example 2, incorporating 5% calcined hydrotalcite, had a strength loss rate of only 6.3% in a 40°C strong salt bath environment, far lower than Comparative Example 1 (32% loss rate) without calcined hydrotalcite. Furthermore, the hydrophobic coating formed by the calcium stearate generated from the slow-release encapsulation layer reaction on the inner wall of the micropores, synergistically with the dense cementitious matrix, blocked the high concentration of chloride ions. - The permeation channels greatly enhance the long-term service life of the stones under deep high-pressure erosion environments.

[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways, characterized in that: By weight, it includes the following components: The mixture comprises 42-52 parts of ultrafine silicate cement, 23-28 parts of ultrafine sulfoaluminate cement, 14-18 parts of mineral powder, 3-6 parts of silica fume, 1-5 parts of calcined hydrotalcite, a water-reducing agent, and a slow-release accelerator. The shell material of the slow-release accelerator is stearic acid, polymer wax, or a mixture thereof, wherein the polymer wax is selected from one or more of Fischer-Tropsch wax, oxidized polyethylene wax, and microcrystalline wax. The core material is selected from at least one of lithium carbonate, lithium sulfate, or sodium aluminate.

2. The rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways according to claim 1, characterized in that: The grouting material also includes water, with a water-cement ratio of 0.9-1.1:1; Alternatively, the shell material may be a compound system of stearic acid and polymer wax, with a mass ratio of 1-3:

1. Alternatively, the number average molecular weight of the polymer wax is 2000-6000, and the melting point is 70-120℃.

3. The rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways according to claim 1, characterized in that: The slow-release coagulant accounts for 0.4-0.6% of the total mass of the dry powder.

4. The rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways according to claim 1, characterized in that: The preparation method of the slow-release accelerator is as follows: preheat the core material to 5-10°C below the melting point of the wall material, spray the molten wall material into the core material under stirring at a uniform speed, and the wall material solidifies on the surface of the core material to obtain the slow-release accelerator. Preferably, the melting point of the wall material is 65-80℃; Preferably, the mass ratio of core material to wall material is 3-6:1, and more preferably 4-5:1; Preferably, the particle size of the core material is 5-50 μm, and more preferably 10-30 μm.

5. The rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways according to claim 1, characterized in that: The preparation method of the calcined hydrotalcite is as follows: place the hydrotalcite raw material with a magnesium-aluminum ratio of 2-3:1 in a high-temperature furnace, raise the temperature to 450-550℃ at a heating rate of 5-10℃ / min, calcine at a constant temperature for 3-5 hours, take it out, and cool it in a dry environment to obtain the product.

6. The rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways according to claim 1, characterized in that: The water-reducing agent is a polycarboxylate-based high-performance water-reducing agent, accounting for 0.08-0.12% of the total mass of the dry powder.

7. The rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways according to claim 1, characterized in that: The particle size distribution of the dry powder is D 10 ≤1.5μm, D 50 The thickness is 4.5μm-5.5μm, D 90 ≤12μm; Preferably, the median particle size distribution D of the ultrafine silicate cement is... 50 The median particle size distribution D of the ultrafine sulfoaluminate cement is 5-6 μm. 50 The particle size distribution is 5-6 μm, and the ore powder is S95 grade granulated blast furnace slag powder with a median particle size distribution D. 50 The median particle size distribution D of the silica fume is 5-6 μm. 50 It is 1-1.5 μm; Preferably, the median particle size distribution D of the ultrafine silicate cement is... 50 The median particle size distribution D of the ultrafine sulfoaluminate cement is 5.405 μm. 50 The particle size distribution is 5.409 μm, and the ore powder is S95 grade granulated blast furnace slag powder with a median particle size distribution D. 50 The median particle size distribution D of the silica fume is 5.817 μm. 50 It is 1.064 μm.

8. The rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways according to claim 1, characterized in that: By weight, it includes the following components: The composition includes 48-52 parts of ultrafine silicate cement, 25-28 parts of ultrafine sulfoaluminate cement, 16-18 parts of mineral powder, 4-6 parts of silica fume, 2-4 parts of calcined hydrotalcite, 0.09-0.11% of the total dry powder mass of water-reducing agent, and 0.45-0.55% of the total dry powder mass of slow-release accelerator. Preferably, by weight, it comprises the following components: 50 parts of ultrafine silicate cement, 27.5 parts of ultrafine sulfoaluminate cement, 17.5 parts of mineral powder, 5 parts of silica fume, 3 parts of calcined hydrotalcite, the amount of water-reducing agent is 0.1% of the total dry powder mass, and the amount of slow-release accelerator is 0.5% of the total dry powder mass.

9. The preparation method of the rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways as described in any one of claims 1-8, characterized in that: Includes the following steps: The grouting material is obtained by mixing its various components in the specified proportions.

10. The preparation method of the rapid-setting, high-strength, erosion-resistant grouting material for treating seepage water in ultra-deep metal mine roadways according to claim 9, characterized in that: During construction, the dry powder and water are mixed at a water-cement ratio of 0.9-1.1:1 to prepare the grouting slurry.

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