A method for treating water inrush in an ultra-deep underground mine pit

Abstract

The present application belongs to the technical field of underground engineering disaster control, and provides a kind of super deep underground mine water inrush control method, pressure relief borehole is constructed on the upstream of water inrush channel and down into the venturi type water power capture pipe, high pressure water is graded by multi-stage throttle cone valve, throat negative pressure suction is used to suck seepage water, and turbine generator is driven to generate power; A liquid containing sodium silicate, nano calcium silicate and magnetic Fe3O4 is prepared, and B liquid containing carbonate, sulfate and heat-loving carbonic anhydrase is prepared, mixed at 50~80 DEG C underground temperature, and calcite-silica gel composite stone body is generated by enzyme catalysis co-precipitation; resistivity CT and electromagnetic field are used to guide slurry directional diffusion in grouting process, and shape memory particles are injected to expand and fill microcracks when heated in later period. The present application converts high pressure water inrush kinetic energy into grouting power and thermal catalytic conditions, realizes in-situ mineralization and consolidation of flowing water, has high plugging success rate, is durable and environmentally friendly, and is suitable for super deep high temperature and high pressure mine water inrush disaster control.

Description

Technical Field

[0001] This invention belongs to the field of underground engineering disaster management technology, specifically a method for managing water inrush in ultra-deep underground mines. Background Technology

[0002] With the depletion of shallow mineral resources, mines both domestically and internationally have entered a phase of deep mining, resulting in a significant increase in the number of ultra-deep mines (exceeding 1000 m in depth). In my country, some metal mines have reached depths of 1500-2000 m. Simultaneously, the high-temperature, high-volume, and high-pressure environments at these deep mines have induced water inrush disasters. Statistics show that in ultra-deep mine water inrush accidents, water pressure exceeds 15 MPa, water temperature is 50-80 ℃, and instantaneous water inflow exceeds 500 m³ / h. 3 / h, the water inrush channels are mostly fault fracture zones, karst fissures or mining-induced fissure networks, with meandering shapes and strong concealment.

[0003] Currently, the main methods for controlling mine water inrush include: surface pre-grouting, underground roadway grouting, diversion grouting, freezing methods, and the recently developed dynamic water grouting technology. However, existing technologies have revealed four common defects under ultra-deep, high-temperature, and high-pressure dynamic water conditions:

[0004] (1) High-pressure water scouring leads to failure of grout retention: In flowing water with a velocity >2 m / s and a pressure >10 MPa, traditional cement-based or cement-water glass grouts are diluted and dispersed by the water flow before initial setting, resulting in a sealing success rate of less than 40%. Even with a dual-liquid fast-setting system, it is difficult to resist the shearing of continuous high-pressure water flow.

[0005] (2) High temperature environment causes abnormal cement slurry setting: the hydration rate of ordinary silicate cement increases rapidly above 50 ℃, the initial consistency rises too quickly, and it is easy to "false setting" or "flash setting", which makes pumping difficult; while chemical slurries (such as polyurethane and acrylate) have uncontrolled polymerization reaction at high temperature, generating a large amount of reaction heat, and even igniting.

[0006] (3) Poor compatibility between grout and injected medium: After solidification, polymer chemical grout forms an organic body, which differs greatly from the mechanical parameters of the surrounding rock. Under repeated pressure fluctuations, it is prone to debonding and cracking, and precipitates toxic monomers that pollute groundwater, which does not meet the requirements of green mines.

[0007] (4) Difficulty in detecting the location and shape of the channel: Conventional drilling is difficult to accurately hit the winding main channel of water inrush, grouting is highly blind, the borehole utilization rate is low, and the project cost remains high.

[0008] To address the problems raised in the background art, those skilled in the art have proposed a method for treating water inrush in ultra-deep underground mines. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a method for treating water inrush in ultra-deep underground mines. This method solves the problems in existing technologies, such as the slurry being diluted and washed away by high-pressure water flow under ultra-deep, high-temperature, and high-pressure dynamic water conditions, resulting in low retention rates, abnormal or ineffective cement slurry setting due to high temperatures, poor compatibility of chemical slurry with surrounding rock and groundwater pollution, as well as difficulties in locating water inrush channels and high degree of blindness in grouting.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A method for treating water inrush in ultra-deep underground mines includes the following steps:

[0012] S1: Construct a pressure relief borehole upstream of the water inrush channel. A Venturi hydraulic capture pipe is installed in the borehole. The pipe consists of a contraction section, a throat section, a diffuser section, and a tail section. A multi-stage throttling cone valve is installed in the contraction section to reduce the pressure of the high-pressure water inrush to normal pressure in stages. A negative pressure suction branch pipe is installed on the outside of the throat section to actively suck up the surrounding seepage water. A hydraulic turbine generator is installed in the tail section to convert pressure energy into electrical energy.

[0013] S2: Prepare a two-component reaction slurry consisting of solution A and solution B. Solution A uses sodium silicate as a carrier and contains nano-calcium silicate seed crystals, magnetic iron oxide nanoparticles, and a rheology stabilizer. Solution B is an aqueous solution containing carbonate, sulfate, and thermophilic carbonic anhydrase.

[0014] S3: Pump liquid A and liquid B separately to the diffusion section of the venturi tube, mix them through the built-in static mixer, and use the temperature of the underground hot water in the mine (50~80 ℃) and the catalytic action of carbonic anhydrase to cause the mixture to undergo a co-precipitation reaction to generate a stone body with an interpenetrating network of calcite and silica gel.

[0015] S4: During the grouting process, cross-hole resistivity computed tomography is used to monitor the grout diffusion direction in real time. An external electromagnetic field is applied by an electromagnetic coil placed at the borehole opening or the tunnel wall to drive the magnetic iron oxide nanoparticles in liquid A and guide the grout to diffuse directionally towards the main water inrush channel.

[0016] S5: In the later stage of grouting, shape memory polymer particles are added to the mixed grout, and the underground high temperature is used to make them expand in volume, fill the cracks and form a load-bearing skeleton.

[0017] S6: After the grouting pressure and diffusion range meet the design requirements, stop grouting, seal the hole, and implement long-term water pressure and flow monitoring.

[0018] Preferably, the constriction section of the Venturi hydraulic capture pipe is equipped with 2 to 4 stages of throttling cone valves, with each stage reducing the pressure by 60% to 80% per stage, and the final outlet pressure ≤ 0.5 MPa.

[0019] Preferably, the ratio of the diameter of the throat section to the inlet diameter of the constriction section is 1:2 to 1:4, and the ratio of the throat length to the diameter is 3 to 6. The pressure inside the throat is adjusted to be 0.01 to 0.05 MPa lower than atmospheric pressure by adjusting the throttle valve.

[0020] Preferably, the particle size of the nano-calcium silicate seed crystals is 30~80 nm, and the mass percentage in solution A is 0.5%~5%; the particle size of the magnetic iron oxide nanoparticles is 50~100 nm, and the mass percentage in solution A is 0.5%~2%.

[0021] Preferably, the thermophilic carbonic anhydrase is derived from thermophilic microorganisms Thermus thermophilus and Bacillus stearothermophilus or halophilic thermophilic bacterium Natronococcus occultus, and the enzyme activity retention rate is not less than 80% in the temperature range of 50~80 °C. The amount added to solution B is 0.01~0.1 parts by weight (based on 100 parts of water).

[0022] Preferably, the shape memory polymer particles are polyurethane-based shape memory particles with a glass transition temperature of 50-65 °C, an initial particle size of 1-3 mm, and a volume expansion ratio of 5-8 times in water at 50-80 °C.

[0023] Preferably, the magnetic field strength of the external electromagnetic field in S4 is 0.1~0.5 T, the frequency is 5~50 Hz, and the magnetic force direction is adjusted in real time according to the resistivity CT imaging results.

[0024] Preferably, the transpore resistivity computed tomography uses an electrode spacing of 0.5~2 m and a sampling frequency of 1~10 Hz to identify the slurry front by the feature of a 10~30% decrease in resistivity in the slurry diffusion region.

[0025] Preferably, when Ca in the water inrush channel 2+ When the concentration is below 200 mg / L, add an additional water-soluble calcium salt (calcium chloride or calcium nitrate) to solution A to increase the Ca concentration in the mixture. 2+ The concentration reaches 800~1500 mg / L.

[0026] Preferably, the electrical energy output by the hydraulic turbine generator is used to drive the transpore resistivity CT acquisition instrument and the electromagnetic coil, thereby achieving energy self-sufficiency.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. This invention converts the high-pressure kinetic energy of the water inrush into electrical energy to power the electromagnetic guidance and monitoring equipment, eliminating the need for additional downhole cable laying or intrinsically safe power supply, ensuring safety and reliability. By using a venturi tube to reduce pressure in stages, the high-speed water flow can be eliminated from scouring the slurry, and the negative pressure of the throat tube can be used to concentrate and extract seepage water, increasing the solidification retention rate of the slurry in the dynamic water environment to over 85%, thus solving the problems of easy slurry dispersion and high failure rate of sealing in traditional methods.

[0029] 2. This invention transforms geothermal energy at 50~80℃ into thermocatalytic conditions for mineralization reactions, and combines carbonic anhydrase to accelerate co-precipitation. The resulting calcite-silica composite has higher strength and better density at high temperatures. By using resistivity CT and electromagnetic field to guide the grout to actively track the meandering main channel, ineffective grouting is reduced by 30%~50%, achieving "turning harm into benefit" and precise sealing under high-temperature conditions.

[0030] 3. This invention utilizes an interpenetrating network of natural minerals and silica gel to form a stone body, ensuring mechanical compatibility with the surrounding rock, non-toxic leaching, and a service life exceeding the mine's service life. By adjusting the reaction solution ratio and shape memory particle parameters, it is applicable to water pressures of 12-25 MPa, water temperatures of 45-85 ℃, and flow rates of 100-1000 m³ / h. 3 / h of various water inrush conditions in ultra-deep mines. Attached Figure Description

[0031] To illustrate the embodiments of the present invention or the prior art, the required drawings will be briefly described below. Obviously, these drawings are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart illustrating the overall process of a method for treating water inrush in ultra-deep underground mines according to the present invention. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0034] As attached Figure 1 As shown:

[0035] Example 1:

[0036] This invention provides a method for treating water inrush in ultra-deep underground mines, comprising the following five core steps:

[0037] Hydraulic capture and pressure staged release: Decompression boreholes are constructed upstream of the water inrush channel, with built-in Venturi hydraulic capture pipes. High water pressure is gradually reduced to normal pressure through multi-stage throttling cone valves. At the same time, the negative pressure of the throat pipe is used to pump out the surrounding seepage water and drive a micro turbine generator to power the monitoring equipment.

[0038] Preparation of two-component authigenic mineral reaction slurry:

[0039] Solution A: Sodium silicate carrier solution, containing nano-calcium silicate seed crystals, magnetic iron oxide nanoparticles and rheology stabilizers;

[0040] Solution B: An aqueous solution of carbonate-sulfate composite activator, with thermophilic carbonic anhydrase added as a biocatalyst.

[0041] Temperature-controlled in-situ mineralization consolidation: A and B solutions are mixed in a static mixer in the diffuser section of a Venturi tube. Under the conditions of a geothermal temperature of 50-80 °C and enzyme catalysis, a co-precipitation reaction occurs to generate calcite (CaCO3) and amorphous silica gel (SiO2·nH2O). The two interpenetrate to form a high-strength, low-permeability rock-like material.

[0042] Resistivity CT and electromagnetic field coordinated guidance: During grouting, the resistivity CT across the borehole is used to image the grout diffusion front in real time; if the grout deviates from the main channel, a directional magnetic field is applied through the electromagnetic coil at the borehole opening to drive the magnetic nanoparticles in liquid A and guide the grout to flow towards the target area.

[0043] Shape memory particle self-expansion reinforcement: Shape memory polyurethane particles with a glass transition temperature of about 55~65℃ are added in the later stage of grouting. When exposed to the high temperature downhole, they expand in volume by 5~8 times, filling micro-cracks and irregular cavities, forming a skeleton reinforcement effect.

[0044] Example 2:

[0045] This embodiment describes the detailed steps and parameters for implementing the present invention.

[0046] S1: Construction of a Hydraulic Capture and Pressure Staged Release System

[0047] Drilling layout: Within 5-25 m upstream of the water inrush point, based on the location results of ground-penetrating radar or microseismic drilling, construct 2-6 directional pressure relief boreholes along the predicted main water inrush channel. The borehole diameter is 75-110 mm, and the dip angle is consistent with the channel dip angle (usually -15° to +45°). The borehole depth penetrates the loosened zone of the surrounding rock and enters the channel extension zone 10-30 m deep. The borehole termination point should be located in an area with a large channel cross-sectional area and relatively gentle water flow.

[0048] Structure of a Venturi hydraulic capture tube: The tube is made of pressure-resistant stainless steel, with a total length of 3-6 m, and is divided into four sections:

[0049] ① Contraction section (inlet section): 0.8~1.5 m in length, with the inner diameter gradually decreasing from the borehole diameter to the throat diameter. 2~4 throttling cone valves are coaxially installed in the contraction section. The opening of each cone valve is adjustable to achieve graded pressure reduction.

[0050] ② Throat section: Length 0.3~0.8 m, diameter 25~50 mm. This section has the highest flow velocity and the lowest pressure (can be reduced to negative pressure -0.05~-0.01 MPa). Two to four bypass negative pressure suction holes are opened on the outside of the throat, which are connected to negative pressure branch pipes with a diameter of 20 mm. The end of the branch pipe extends to the rock strata around the borehole, using negative pressure to actively suck up seepage water from nearby fissures and prevent seepage water from interfering with the sealing of the main channel.

[0051] ③ Diffusion section: 1.0~2.0 m in length, with the inner diameter gradually expanding from the throat diameter to the original borehole diameter. A static mixer (spiral blade or Kernis type) is installed inside the diffusion section for subsequent mixing of liquids A and B.

[0052] ④ Tail section: A miniature hydraulic turbine generator is installed. The turbine blades are driven by the low-pressure water flow at the outlet of the diffuser section, converting the remaining pressure energy into electrical energy (typical output power 50~500 W), which powers the data acquisition instrument and electromagnetic coil of the transpore resistivity CT system through a cable.

[0053] Operating Procedure: Lower the venturi tube to the predetermined depth in the borehole, with the contraction section facing upstream of the water inrush. Open the throttling cone valve to the preset opening. The high-pressure water flow passes through each stage of the cone valve, reducing pressure and creating negative pressure at the throat, which then begins to draw water from the sidewalls. After flowing through the diffuser section, the water velocity decreases, ultimately driving the turbine to generate electricity. Adjust the cone valve opening to stabilize the negative pressure in the throat at -0.02 ~ -0.05 MPa, ensuring that the surrounding water is continuously pumped into the main channel, preventing it from accumulating in the bypass and forming secondary water inrush points.

[0054] S2: Preparation of two-component authigenic mineral reaction slurry

[0055] The components and functions of liquid A and liquid B are described in Tables 1 and 2 below:

[0056] Sodium silicate solution 100 units (modulus 2.6~3.2, Baumé degree 45~52) Provides silicate ions, which react to form a silica gel framework; simultaneously, it acts as a carrier to disperse solid particles. Nano-silica-calcium crystal seeds 2-5 parts (particle size 30-80 nm) <![CDATA[Providing calcite heterogeneous nucleation sites to accelerate CaCO₃ precipitation and prevent excessively long reaction induction period]]> Magnetic iron oxide nanoparticles 0.5 to 2 parts (particle size 50 to 100 nm) This imparts responsiveness to magnetic fields to the slurry, enabling electromagnetic guidance; it also slightly increases the slurry density. rheology stabilizers 0.1~0.5 parts (hydroxyethyl cellulose or xanthan gum) Prevents nanoparticle sedimentation, maintains slurry stability, and regulates viscosity. Water (optional) 0-20 parts (adjust initial viscosity) When sodium silicate has a high Baume degree, dilution is required.

[0057] Table 1. Components and Functional Description of Liquid A

[0058] water 100 copies Solvents and reaction media Sodium carbonate 15-25 servings It provides carbonate ions, which react with calcium ions to form calcite; it also provides an alkaline pH (11~12). Aluminum sulfate 5-10 servings It provides aluminum and sulfate ions, adjusts the pH, promotes silica gelation, and generates a small amount of ettringite to enhance early strength. thermophilic carbonic anhydrase 0.01~0.05 parts (enzyme activity ≥5000 U / mg) <![CDATA[Catalyzes the hydration reaction of CO₂ (CO₂ + H₂O ⇌ H₂CO₃), greatly increases the generation rate of carbonate ions, and enables the precipitation reaction to be completed within several minutes]]> Surfactant (optional) 0.05~0.1 parts (sodium dodecylbenzenesulfonate) Reduce the surface tension of the mixture and enhance its wettability with rock fissures.

[0059] Table 2. Components and Functional Description of Liquid B

[0060] Liquid A and liquid B are stored in two separate tanks equipped with stirring devices (capacity 2~5 m³). During use, they are pumped using two frequency-controlled high-pressure grouting pumps (maximum pressure 25 MPa, discharge rate adjustable from 50 to 200 L / min). The volume ratio of liquid A to liquid B is controlled at 1:0.8~1.2. Before pumping, liquid A should be ultrasonically dispersed or stirred at high speed for 10~20 min to ensure uniform suspension of the nanoparticles.

[0061] S3: Temperature-controlled in-situ mineralization consolidation reaction mechanism and parameters

[0062] Liquids A and B are delivered to the diffusion section of a venturi tube via a high-pressure hose and thoroughly mixed in a static mixer. The following main chemical reactions occur after mixing:

[0063] (1) Carbonic anhydrase catalyzes CO2 hydration

[0064] CO2 + H2O 碳酸酐酶 H2CO3⇌H + +HCO3 - ⇌2H + +CO3 2-

[0065] The reaction rate constant is increased by approximately 10% compared to enzyme-free catalysis. 6 At 50-80 °C, CO2 reaches saturation and then converts to HCO3. - / CO3 2- It only takes a few seconds.

[0066] (2) The calcium ions in the calcite precipitation mixture originate from formation water (ultra-deep mine water typically contains 200-800 mg / L Ca²⁺) and soluble calcium salts added to solution A (5-10 parts of calcium chloride can be added if necessary). Calcium ions combine with carbonate ions:

[0067] Ca 2+ +CO3 2- →CaCO3↓

[0068] Nano-silica-calcium seed crystals provide a nucleation surface for CaCO3, allowing the precipitate to form microcrystalline aggregates within 3-8 minutes.

[0069] (3) Silica gel formation and crosslinking

[0070] Sodium silicate reacts with CO2 or acidic components under alkaline conditions:

[0071] Na2SiO3+CO2+H2O→SiO2·nH2O↓+Na2CO3

[0072] The generated silica gel possesses a three-dimensional network structure that encapsulates calcite microcrystals, forming a calcite-silicone interpenetrating composite material. This material exhibits superior mechanical properties compared to its single-component counterparts: compressive strength 25–40 MPa, tensile strength 3–6 MPa, and permeability coefficient <1×10⁻⁶ MPa. -8 cm / s.

[0073] Reaction condition control:

[0074] Using geothermal energy (50~80 ℃) from the mine as the heat source for the reaction, no external heating is required.

[0075] The mixed slurry has a residence time of about 2 to 5 seconds in the diffusion section, which is enough to complete the initial nucleation. After entering the channel with the water flow, it continues to solidify during the flow process, forming a stone body that conforms to the shape of the channel.

[0076] The initial setting time is controlled by adjusting the volume ratio of solution A to solution B and the amount of aluminum sulfate used (the higher the volume ratio and the more aluminum sulfate, the faster the initial setting).

[0077] S4: Resistivity CT and Electromagnetic Field Co-guided

[0078] Layout of the trans-hole resistivity CT system: Two rows of shallow holes (50 mm diameter, 3-5 m depth, 2-3 m spacing) are pre-constructed on both sides of the roadway in the treatment area. Medical stainless steel electrodes (ring-shaped or dot-shaped) are installed in the holes and connected to the resistivity acquisition instrument via multi-core cables. During grouting, the acquisition instrument automatically scans according to the "four-electrode method" or "two-electrode method," with a sampling frequency of 1-10 Hz, generating two-dimensional or three-dimensional resistivity profiles. Because liquid A contains magnetic Fe3O4 nanoparticles (resistivity approximately 10⁻⁶ Hz), the resistivity profile is obtained. -2 Ω∙m, much lower than 10 of the surrounding rock 2 ~10 4 (Ω∙m), the resistivity of the slurry diffusion region will decrease significantly by 10~30%, which will appear as a clear low-resistivity anomalous band on resistivity CT images.

[0079] Electromagnetic guidance system:

[0080] An electromagnetic coil (300-800 turns, 0.3-0.6 m inner diameter) is installed at the borehole opening or on the tunnel wall and connected to a low-frequency AC power supply powered by a hydraulic turbine generator. When resistivity CT shows that the slurry diffusion direction deviates from the design direction (e.g., towards secondary fractures), the operator adjusts the current direction and intensity of the coil (0.1-0.5 T magnetic field strength, 5-50 Hz frequency) to generate a gradient magnetic field. Fe3O4 nanoparticles experience magnetic force in the magnetic field.

[0081] F = ∇(m∙B)

[0082] Where m is the particle magnetic moment and B is the magnetic induction intensity. This force drives the grout to move in the direction of the largest magnetic field gradient, thereby achieving "targeted grouting". Field practice shows that after the magnetic field is turned on, the main direction of grout diffusion can be twisted by 15° to 30° within 5 to 15 minutes, effectively blocking the main channel.

[0083] S5: Shape memory particles self-expansion reinforcement and terminal pores

[0084] Preparation of shape memory particles: Polyurethane-based shape memory polymers (SMP) are selected, and particles with a diameter of 1-3 mm are obtained using a granulator. The glass transition temperature (Tg) is designed to be 55-65 ℃ (achieved by adjusting the ratio of soft to hard segments). Below Tg, the particles are in a glassy state and dimensionally stable; above Tg, the polymer chain segment mobility is enhanced, and the particles elastically recover their original "memory" shape (usually porous or expanded) with a volume expansion of 5-8 times.

[0085] Injection Timing: When the cumulative grouting volume reaches 70%~85% of the designed total, and resistivity CT shows that most of the main channel has been filled, suspend the injection of liquids A and B. Instead, use a small screw pump to mix shape memory particles with a small amount of liquid A (as a carrier) and inject it into the mixer. The injection rate should be controlled at 5~10 kg / min, and the total amount should be estimated based on the remaining cavity volume of the channel (generally 0.5~2.0 m³). 3 ).

[0086] Expansion and solidification: After entering the water inrush channel with the slurry, the particles rapidly expand at a ground temperature of around 60 ℃, squeezing and filling the residual water in the cracks and sealing the micro-channels, while also acting as a rigid skeleton to disperse ground pressure. After the temperature drops to ambient temperature, the particles maintain their expanded state and form a fiber-reinforced composite structure with the calcite-silica composite, significantly improving the curtain wall's resistance to deformation.

[0087] Termination of grouting is indicated when the grouting pressure rises to 1.5 to 2.0 times the initial hydrostatic pressure and remains unchanged for 20 minutes; the grout return rate at the borehole opening is less than 5 L / min; and the resistivity CT shows that the low-resistivity area has covered the designed curtain area. At this point, grouting should be stopped.

[0088] S6: Sealing and Long-Term Monitoring

[0089] After grouting, wait at least 24 hours for the stone to reach more than 60% of its 24-hour strength. Then remove the Venturi tube and turbine generator (which can be reused), and clean the remaining grout inside the tube with high-pressure water.

[0090] The borehole is filled with micro-expansion cement mortar of grade not lower than M40, and the sealing length is not less than 1 / 3 of the borehole depth (top section sealing).

[0091] A pressure transmitter (range 0~2 MPa) and an electromagnetic flowmeter (accuracy 0.5%) are installed downstream of the water inrush point. Data is transmitted to the ground control center via a downhole ring network and continuously monitored for at least 6 months. The residual water inflow after treatment must be less than 5% of the original water inflow and remain stable over the long term.

[0092] Example 3:

[0093] This embodiment, combined with a typical case of water inrush treatment in an ultra-deep mine, further illustrates the present invention in detail. The embodiment is only used to explain the present invention and does not constitute a limitation on the scope of protection.

[0094] Project Overview: An iron mine with a mining depth of 1450 m. The water inrush channel is located in the F3 reverse fault fracture zone (1.2~2.5 m wide). The water pressure is 18.5 MPa, the flow rate is 320 m³ / h, the water temperature is 62 ℃, and the water quality contains Ca. 2+ 568 mg / L.

[0095] Construction parameters:

[0096] Drilling: 4 Φ95 mm pressure relief drill holes, with a depth of 21~24 m and an inclination angle of 35°.

[0097] Venturi tube: 3-stage throttling (18.5→5.8→1.2→0.35 MPa), throat Φ35 mm, negative pressure -0.035MPa, turbine generator power 210~240 W.

[0098] Solution A: 1000 kg of sodium silicate with a modulus of 2.8, 35 kg of nano-calcium silicate, 12 kg of Fe3O4, 2.5 kg of hydroxyethyl cellulose, and 50 kg of water.

[0099] Solution B: 1000 kg water, 220 kg sodium carbonate, 90 kg aluminum sulfate, 0.5 g carbonic anhydrase, 0.8 kg sodium dodecylbenzenesulfonate.

[0100] A:B volume ratio = 1:1.1, shape memory particles (Tg = 60 ℃, expands 6.5 times) 20 kg.

[0101] Construction process:

[0102] Install a venturi tube and use negative pressure in the throat to draw out seepage water at a rate of 15 L / min.

[0103] Grouting flow rate is 180 L / min, and the temperature of the mixed grout is 59 ℃.

[0104] After 35 minutes of grouting, resistivity CT showed that the grout was biased towards the southwest secondary fracture. The electromagnetic coil (0.25 T, 20 Hz) was started, and after 8 minutes it was redirected to the main channel.

[0105] After a cumulative grouting depth of 19.6 m³, 20 kg of shape memory particles were injected, increasing the pressure to 2.9 MPa. Grouting continued for another 2.3 m. 3 Final pressure 3.1 MPa.

[0106] Treatment effect:

[0107] Initial setting time: 4 min 20 s; compressive strength: 26.3 MPa at 8 h; compressive strength: 37.8 MPa at 28 days; permeability coefficient: 4.7 × 10⁻⁶. -9 cm / s.

[0108] Water inflow: decreased to 48 m after 2 hours 3 / h, 2.6 m after 24 hours 3 / h, stabilized at 0.8 m after 72 h. 3 / h.

[0109] After 6 months of long-term monitoring, the residual water volume was 0.5~1.2 m³. 3 / h, the stone body is well cemented with the fault breccia.

[0110] The embodiments of this invention are described primarily for illustrative and explanatory purposes. Although we have provided detailed descriptions and explicit demonstrations of specific implementations of this invention, it should be clarified that the above content is merely illustrative and should not be construed as an absolute limitation on the scope or substance of this invention. For those skilled in the art, appropriate adjustments, modifications, substitutions, and various possible alterations and variations can be made to the foregoing embodiments within their applicable scope, without departing from the spirit and core principles of this invention.

Claims

1. A method for treating water inrush in ultra-deep underground mines, characterized in that, Includes the following steps: S1: Construct a pressure relief borehole upstream of the water inrush channel. A Venturi hydraulic capture pipe is installed in the borehole. The pipe consists of a contraction section, a throat section, a diffuser section, and a tail section. A multi-stage throttling cone valve is installed in the contraction section to reduce the pressure of the high-pressure water inrush to normal pressure in stages. A negative pressure suction branch pipe is installed on the outside of the throat section to actively suck up the surrounding seepage water. A hydraulic turbine generator is installed in the tail section to convert pressure energy into electrical energy. S2: Prepare a two-component reaction slurry consisting of solution A and solution B. Solution A uses sodium silicate as a carrier and contains nano-calcium silicate seed crystals, magnetic iron oxide nanoparticles, and a rheology stabilizer. Solution B is an aqueous solution containing carbonate, sulfate, and thermophilic carbonic anhydrase. S3: Pump liquid A and liquid B separately to the diffusion section of the venturi tube, mix them through the built-in static mixer, and use the temperature of the underground hot water in the mine (50~80 ℃) and the catalytic action of carbonic anhydrase to cause the mixture to undergo a co-precipitation reaction to generate a stone body with an interpenetrating network of calcite and silica gel. S4: During the grouting process, cross-hole resistivity computed tomography is used to monitor the grout diffusion direction in real time. An external electromagnetic field is applied by an electromagnetic coil placed at the borehole opening or the tunnel wall to drive the magnetic iron oxide nanoparticles in liquid A and guide the grout to diffuse directionally towards the main water inrush channel. S5: In the later stage of grouting, shape memory polymer particles are added to the mixed grout, and the underground high temperature is used to make them expand in volume, fill the cracks and form a load-bearing skeleton. S6: After the grouting pressure and diffusion range meet the design requirements, stop grouting, seal the hole, and implement long-term water pressure and flow monitoring.

2. The method for treating water inrush in ultra-deep underground mines as described in claim 1, characterized in that: The constriction section of the Venturi hydraulic capture pipe is equipped with 2 to 4 stages of throttling cone valves, with each stage reducing the pressure by 60% to 80% per stage, and the final outlet pressure ≤ 0.5 MPa.

3. The method for treating water inrush in ultra-deep underground mines as described in claim 1, characterized in that: The ratio of the diameter of the throat section to the inlet diameter of the constriction section is 1:2 to 1:4, and the ratio of the throat length to the diameter is 3 to 6. The pressure inside the throat is kept 0.01 to 0.05 MPa lower than atmospheric pressure by adjusting the throttle valve.

4. The method for treating water inrush in ultra-deep underground mines as described in claim 1, characterized in that: The nano-calcium silicate seed crystals have a particle size of 30-80 nm and a mass percentage of 0.5%-5% in solution A; the magnetic iron oxide nanoparticles have a particle size of 50-100 nm and a mass percentage of 0.5%-2% in solution A.

5. The method for treating water inrush in ultra-deep underground mines as described in claim 1, characterized in that: The thermophilic carbonic anhydrase is derived from thermophilic microorganisms Thermus thermophilus and Bacillus stearothermophilus or halophilic thermophilic bacterium Natronococcus occultus. The enzyme activity retention rate is not less than 80% in the temperature range of 50~80 ℃, and the amount added to solution B is 0.01~0.1 parts by weight (based on 100 parts of water).

6. The method for treating water inrush in ultra-deep underground mines as described in claim 1, characterized in that: The shape memory polymer particles are polyurethane-based shape memory particles with a glass transition temperature of 50-65 ℃, an original particle size of 1-3 mm, and a volume expansion ratio of 5-8 times in water at 50-80 ℃.

7. The method for treating water inrush in ultra-deep underground mines as described in claim 1, characterized in that: The magnetic field strength of the external electromagnetic field in S4 is 0.1~0.5 T, the frequency is 5~50 Hz, and the magnetic force direction is adjusted in real time according to the resistivity CT imaging results.

8. The method for treating water inrush in ultra-deep underground mines as described in claim 1, characterized in that: The transpore resistivity computed tomography scan uses an electrode spacing of 0.5~2 m and a sampling frequency of 1~10 Hz to identify the slurry front by the feature that the resistivity of the slurry diffusion region decreases by 10~30%.

9. The method for treating water inrush in ultra-deep underground mines as described in claim 1, characterized in that: When Ca in the water inrush channel 2+ When the concentration is below 200 mg / L, add an additional water-soluble calcium salt (calcium chloride or calcium nitrate) to solution A to increase the Ca concentration in the mixture. 2 + The concentration reaches 800~1500 mg / L.

10. The method for treating water inrush in ultra-deep underground mines as described in claim 1, characterized in that: The electrical energy output by the hydraulic turbine generator is used to drive the transpore resistivity CT acquisition instrument and electromagnetic coil, achieving energy self-sufficiency.

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