A method for disposing solid waste coal gangue by grouting and reducing settlement

Abstract

The application provides a solid waste coal gangue disposal grouting subsidence reduction method, relates to the technical field of coal gangue treatment, and comprises the following steps: crushing, screening and drying operations are performed on the coal gangue; a dynamic proportioning model is constructed; the mass ratio of coal gangue powder, fly ash, composite portland cement, carbide slag and desulfurization gypsum is adjusted based on the rheological properties of the slurry and the injection layer position parameters; the various ingredients are mixed and the stability is adjusted; a three-dimensional space model of the drill hole group is established, and the injection timing is dynamically adjusted based on the formation stress monitoring data; a modular grouting station is constructed, and three-stage pressure control is implemented for grouting; according to the dynamic proportioning model, the mass ratio of the ingredients is adjusted, the coal gangue is used as the core raw material, the industrial waste residues such as carbide slag are combined, the utilization rate of the solid waste is greater than or equal to 95%, the cement consumption is reduced, and the online density meter and the pH sensor are arranged; the ingredients are replenished according to the slurry specific gravity set value, and the stability of the slurry is maintained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal gangue treatment, and particularly relates to a solid waste coal gangue disposal grouting subsidence reduction method. BACKGROUND

[0002] Coal gangue is a solid waste discharged in the process of coal mining and coal washing, is a black gray rock with low carbon content and harder than coal, including tunneling gangue in the process of tunneling, gangue mined from the roof, floor and interlayer in the process of mining, and washing gangue picked up in the process of coal washing;

[0003] As a solid waste generated in the process of coal mining, if not properly treated, coal gangue will not only occupy a large amount of land resources, but also may pollute the environment. The existing coal gangue disposal method is to directly prepare a slurry from the crushed and powdered coal gangue, and then manually inject the slurry into the separation space in the process of overburden damage to fill the space, so as to inhibit the further damage of the overburden in the grouting layer, slow down the propagation speed of the overburden moving to the surface, control the movement of the rock stratum, and ultimately achieve the purpose of reducing the surface subsidence. However, the existing technology has the following shortcomings:

[0004] The mixture of coal gangue powder and other additives (such as cement and bentonite) lacks dynamic proportioning optimization design, and is prone to slurry segregation, stratification and specific gravity change, affecting the stability of grouting;

[0005] Impurities are easily left on the surface during the coal gangue cleaning process, and the particle size control in the crushing and powdering process is not accurate, resulting in poor slurry flowability and uneven grouting filling, which requires repeated slurry supplementing and wastes materials;

[0006] The existing technology relies on experience to set the grouting pressure and flow, lacks a closed-loop control mechanism based on real-time feedback of stratum stress, and causes significant fluctuation of the subsidence reduction rate, especially in fault development areas, which easily causes slurry escape or local overpressure;

[0007] Therefore, the present application provides a solid waste coal gangue disposal grouting subsidence reduction method to solve the problems in the prior art. SUMMARY

[0008] In view of the above problems, the present application provides a solid waste coal gangue disposal grouting subsidence reduction method. The solid waste coal gangue disposal grouting subsidence reduction method adjusts the batching mass ratio according to a dynamic proportioning model, takes coal gangue as the core raw material, combines with industrial waste residues such as calcium carbide slag, realizes a solid waste utilization rate of 95%, reduces the cement dosage, and sets an online densimeter and a pH sensor to supplement materials according to the slurry specific gravity set value, so as to maintain the stability of the slurry.

[0009] To achieve the purpose of the present application, the present application realizes the method by the following technical solutions: a solid waste coal gangue disposal grouting settlement reduction method, comprising the following steps:

[0010] S1: crushing, screening and drying operations are performed on the coal gangue;

[0011] S2: a dynamic proportioning model is constructed, and the mass ratio of coal gangue powder, fly ash, composite portland cement, carbide slag and desulfurization gypsum is adjusted based on the rheological properties of the slurry and the injection layer position parameters;

[0012] S3: the various ingredients are mixed and the stability is adjusted;

[0013] S4: a three-dimensional space model of the drill hole group is established, and the grouting timing is dynamically adjusted based on the formation stress monitoring data;

[0014] S5: a modular grouting station is constructed, and three-stage pressure control is implemented for grouting;

[0015] S6: a sensing system is constructed to monitor the slurry diffusion radius and the strength of the solidified body in real time.

[0016] Further improvement lies in that the S1 comprises the following steps:

[0017] The coal gangue is crushed by a crusher and a high-pressure water jet cleaning device, the particle size is controlled to be ≤10mm, the forced mixing of the materials and the cleaning liquid is realized by a stirrer, and the surface impurities are removed by an ultrasonic oscillation device;

[0018] A double-layer vibrating screen mechanism is provided, the aperture is controlled to be 15mm-8mm, the particle size distribution is monitored in real time by a photoelectric sensor, and the closed-circuit crushing of the oversized materials is implemented;

[0019] A microwave drying unit is configured to reduce the moisture content of the coal gangue to below 3%.

[0020] Further improvement lies in that the S2 comprises the following steps:

[0021] A dynamic proportioning model is constructed, the rheological properties viscosity of the slurry is 1500-2500cP, the injection layer position parameters porosity is 15-35%, and the ingredient adjustment is performed by a PLC controller;

[0022] The adjustment is performed according to the following mass ratio: coal gangue powder 45-55 parts, fly ash 15-25 parts, composite portland cement 25-35 parts, carbide slag 5-10 parts, and desulfurization gypsum 5-15 parts.

[0023] Further improvement lies in that the S3 comprises the following steps:

[0024] The adjusted ingredients are stirred by a stirrer, the stirring speed is controlled at 1000-1500 r / min, and the stirring time is 10-20 min;

[0025] After stirring, ball milling is performed, and after ball milling to 200 mesh, water is mixed at a mass ratio of 0.85-0.95 to form a flowable slurry;

[0026] An online densitometer and a pH sensor are arranged, and when the specific gravity of the slurry deviates from the set value 1.65±0.05 g / cm³, the material is supplemented to maintain the stability of the slurry.

[0027] Further improvement lies in that the S4 comprises the following steps:

[0028] A three-dimensional space model of the borehole group is established, and the grouting timing is dynamically adjusted based on the formation stress monitoring data, taking filling the high stress concentration area as the benchmark;

[0029] An airplane-type hole arrangement method is adopted, a main hole is arranged in the middle of the working face, branch holes are arranged on both sides, the boreholes of adjacent working faces are connected in staggered positions, a continuous grouting network is formed, and the filling range is expanded.

[0030] Further improvement lies in that in the S5, a modular grouting station is constructed, a pretreatment unit, a stirring tank and a high-pressure grouting pump are integrated, the outlet pressure is controlled at 0-15 MPa, and the rapid movement is realized through a sliding rail base;

[0031] A self-cleaning grouting pipeline is designed, a polyurethane wear-resistant layer is lined in the pipe wall, and a pulse backwashing device is used to prevent pipe blockage;

[0032] A pressure sensor is installed in the grouting pipeline to monitor the grouting pressure in real time, and the slurry concentration and grouting rate are controlled through PLC.

[0033] Further improvement lies in that the modular grouting station is connected to an Internet of Things monitoring platform through a 5G communication module, and the grouting pressure, flow, and slurry consistency parameters are remotely diagnosed and fault warned.

[0034] Further improvement lies in that in the S5, the three-stage pressure control comprises the following steps:

[0035] In the initial stage, 8-10 MPa high pressure is used to rapidly fill the interlayer cavity;

[0036] In the middle stage, the pressure is switched to 5-6 MPa for medium-pressure penetration and reinforcement;

[0037] In the final stage, the pressure is maintained at 3-4 MPa for stable consolidation, and the overall duration is ≥2 h.

[0038] Further improvement lies in that: in S6, a distributed optical fiber sensing system is deployed, with a spatial resolution of 1m, to monitor the slurry diffusion radius and the solidified body strength in real time, wherein, based on the compressive strength of greater than or equal to 15MPa, a grouting efficiency thermodynamic diagram is generated to guide parameter optimization.

[0039] Further improvement lies in that: a distributed optical fiber sensing system is deployed, a scattering enhanced optical fiber is arranged along the grouting area to perform continuous coverage and millimeter level displacement monitoring, based on an optical frequency domain reflection technology, with a dynamic range of greater than or equal to 120dB, 20 monitoring points per meter, temperature and strain data are synchronously collected, and the sampling rate is controlled to be 100Ksps to meet the demand of capturing the transient process of slurry flow.

[0040] The beneficial effects of the present application are:

[0041] 1. According to the dynamic proportioning model, the present application adjusts the material ratio, takes coal gangue as the core raw material, combines with industrial waste residues such as carbide slag, realizes a utilization rate of solid waste of greater than or equal to 95%, reduces the cement dosage, and simultaneously sets an online densimeter and a pH sensor to supplement materials according to the slurry specific gravity set value to maintain the stability of the slurry.

[0042] 2. The present application realizes forced mixing of materials and cleaning liquid through a stirrer, removes surface impurities through an ultrasonic oscillation device, realizes real-time monitoring of particle gradation through a double-layer vibrating screen separation mechanism in cooperation with a photoelectric sensor, and configures a microwave drying unit for drying to improve the quality and utilization rate of coal gangue.

[0043] 3. The present application implements three-stage pressure control for grouting, based on a dynamic grouting technology of pressure feedback, combines with drilling network optimization to improve filling uniformity and efficiency, avoids the hysteresis of traditional manual control, deploys a distributed optical fiber sensing system to monitor the slurry diffusion radius and the solidified body strength in real time, generates a grouting efficiency thermodynamic diagram to guide parameter optimization, and reduces the surface subsidence rate by greater than or equal to 70%. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 The present application is a method step diagram. DETAILED DESCRIPTION

[0045] In order to deepen the understanding of the present application, the present application will be further described in combination with examples, and the present examples are only used to explain the present application and do not constitute a limitation on the protection scope of the present application.

[0046] Example 1

[0047] According to Figure 1 As shown in the figure, the present embodiment proposes a solid waste coal gangue disposal grouting subsidence reduction method, including the following steps:

[0048] S1: crushing, screening and drying operations are performed on coal gangue; specifically including the following steps: using a crusher and a high-pressure water jet cleaning device to crush the coal gangue, controlling the particle size to be ≤10 mm, realizing forced mixing of the material and the cleaning liquid through a stirrer, and removing surface impurities in combination with an ultrasonic oscillation device; a double-layer vibrating screen separation mechanism is provided, the aperture is controlled to be 15 mm-8 mm, the particle size distribution is monitored in real time through a photoelectric sensor, and closed-circuit crushing is performed on the oversize material; a microwave drying unit is configured to reduce the moisture content of the coal gangue to below 3%. The ultrasonic oscillation device (frequency 28 kHz) removes surface clay attachments, the microwave drying unit (power 6 kW, processing capacity 2 t / h) reduces the moisture content of the coal gangue to below 3% through a temperature control system (80±5℃), and solidification delay of the slurry is avoided.

[0049] S2: a dynamic proportioning model is constructed, the mass ratio of coal gangue powder, fly ash, composite Portland cement, carbide slag and desulfurization gypsum is adjusted based on the rheological properties of the slurry and the injection layer position parameters; specifically including the following steps: a dynamic proportioning model is constructed, the rheological properties of the slurry, the viscosity is 1500-2500 cP, and the injection layer position parameters, the porosity is 15-35%, are adjusted by a PLC controller; the mass ratio is adjusted as follows: coal gangue powder 45 parts, fly ash 15 parts, composite Portland cement 25 parts, carbide slag 5 parts, and desulfurization gypsum 5 parts. The coal gangue powder is used as the aggregate skeleton, the fly ash fills the pores, the composite Portland cement provides the cementing strength, and the carbide slag and the desulfurization gypsum adjust the setting time and the expansion coefficient; a viscosity-porosity double objective function is established: when the porosity is >25%, the viscosity set value is reduced to 1800 cP to enhance the permeability; when the porosity is <20%, the viscosity is increased to 2200 cP to prevent slurry loss; the real-time data of the weighing sensor are processed by a fuzzy PID algorithm to dynamically compensate for the moisture content fluctuation of the raw materials (compensation accuracy ±0.5%); the rheometer monitoring data are integrated through the OPC UA protocol, the proportioning parameters are updated every 15 seconds, and the viscosity deviation is ensured to be ≤±5%; for every 5% increase in porosity, the fly ash proportion is increased by 3-5 parts to optimize the particle size distribution, and the coal gangue particle size is adjusted to 0.5-1.2 mm; for every 2 parts increase in the amount of carbide slag, 1.5 parts of desulfurization gypsum needs to be added synchronously to balance the Ca / Si molar ratio and prevent volume shrinkage and cracking.

[0050] S3: mixing various ingredients and adjusting stability; specifically including the following steps: the adjusted ingredients are stirred by a stirrer, the stirring speed is controlled at 1000-1500 r / min, and the stirring time is 10-20 min; after stirring, ball milling is performed, and the ball-milled material is mixed with water at a mass ratio of 0.85-0.95 to form a flowable slurry; an online densimeter and a pH sensor are provided, and when the specific gravity of the slurry deviates from the set value 1.65±0.05 g / cm³, the material is supplemented to maintain the stability of the slurry.

[0051] S4: Establish a three-dimensional spatial model of the borehole group, dynamically adjust the grouting timing based on the stratum stress monitoring data; specifically including the following steps: establish a three-dimensional spatial model of the borehole group, dynamically adjust the grouting timing based on the stratum stress monitoring data, and take the first filling of high stress concentration area as the benchmark; adopt the airplane drilling method, set main holes in the middle of the working face and branch holes on both sides, connect adjacent working face boreholes at different horizons to form a continuous grouting network, and expand the filling range. Directional drilling to the fissure below the key stratum of overburden, forming a continuous support zone after grouting, inhibiting rock movement, and surface subsidence reduction rate ≥70.

[0052] S5: Construct a modular grouting station and implement three-stage pressure control for grouting; Construct a modular grouting station, integrate a pretreatment unit, a mixing tank, and a high-pressure grouting pump, control the outlet pressure to 0-15 MPa, and achieve rapid movement through a sliding rail base; Design a self-cleaning grouting pipeline with a polyurethane wear-resistant layer on the inner wall, and a pulse backflushing device to prevent pipe blockage; Install pressure sensors in the grouting pipeline to monitor grouting pressure in real time, and control slurry concentration and grouting rate through PLC. Connect the modular grouting station to the Internet of Things monitoring platform through the 5G communication module to remotely diagnose and provide early warning for grouting pressure, flow, and slurry consistency parameters. Implement three-stage pressure control including the following steps: initial high-pressure rapid filling of 8-10 MPa to fill the separation cavity; medium-term switching to 5-6 MPa medium-pressure penetration and reinforcement; and final stable consolidation at 3-4 MPa, with a total duration of ≥2h. The pressure gradient grouting control strategy increases the utilization rate of grouting materials to 92% and reduces the surface subsidence coefficient to 0.08.

[0053] S6: Construct a sensing system to monitor the slurry diffusion radius and solidified body strength in real time. Deploy a distributed optical fiber sensing system with a spatial resolution of 1m to monitor the slurry diffusion radius and solidified body strength in real time, where a compressive strength of ≥15MPa is taken as the benchmark to generate a grouting efficiency thermal map, which guides parameter optimization. Deploy a distributed optical fiber sensing system along the grouting area to lay scattered enhanced optical fibers for continuous coverage and millimeter-level displacement monitoring. Based on the optical frequency domain reflection technology, the dynamic range is ≥120dB, there are 20 monitoring points per meter, temperature and strain data are collected synchronously, the sampling rate is controlled at 100Ksps, and the demand for capturing the transient process of slurry flow is met.

[0054] A double-channel distributed optical fiber strain monitoring system is adopted, a scattering enhanced optical fiber is arranged along the grouting area, a spatial resolution of 1 m is achieved, a millimeter level displacement monitoring of the slurry diffusion radius is supported (error ≤5 cm); based on the optical frequency domain reflection (OFDR) technology, a dynamic range ≥120 dB, 20 monitoring points per meter, temperature (-20~60℃) and strain (-5%~+3%) data are synchronously collected, a sampling rate 100Ksps, the transient process capture demand of the slurry flow is met; a slurry diffusion gradient model is constructed through the strain distribution data (spatial monitoring point density 20 points / m), the environmental vibration interference is eliminated through the Kalman filtering algorithm, the diffusion radius (accuracy ±0.3 m) is calculated in real time; the mapping relationship (R²≥0.95) of the optical fiber strain and the compressive strength is established, the alarm is triggered when the strain value reaches the critical threshold (corresponding to the compressive strength ≥15 MPa), and the thermal expansion effect error is eliminated through the temperature compensation algorithm (compensation rate >90%); the optical time domain and the optical frequency domain data are integrated, the Kriging interpolation algorithm is used to generate a three-dimensional thermal map, the slurry diffusion speed (m / min), the consolidation strength distribution (MPa) and the temperature abnormal area (ΔT≥0.5℃) are dynamically displayed; according to the data density (≥500,000 points / minute) of the thermal map, the transmission bandwidth is dynamically adjusted to 1.2 Gbps through the Ethernet interface, ensuring zero packet loss of data; based on the strain rate threshold (≤0.1με / s), the grouting pressure is adjusted in real time, and the over-diffusion of the slurry or the cracking of the solidified body is prevented.

[0055] Embodiment Two

[0056] According to Figure 1 As shown in the figure, the embodiment proposes a solid waste coal gangue disposal grouting settlement reduction method, including the following steps:

[0057] S1: crushing, screening and drying operations are performed on the coal gangue; specifically including the following steps: a crusher and a high-pressure water jet cleaning device are used to crush the coal gangue, the particle size is controlled to be ≤10 mm, a stirrer is used to realize forced mixing of the material and the cleaning liquid, and an ultrasonic oscillation device is used to remove surface impurities; a double-layer vibrating screen separation mechanism is set, the aperture is controlled to be 15 mm-8 mm, a photoelectric sensor is used to monitor the particle size distribution in real time, and closed-circuit crushing is performed on the super-particle size material; a microwave drying unit is configured, and the moisture content of the coal gangue is reduced to below 3%. The ultrasonic oscillation device (frequency 28 kHz) removes the surface clay attachments, the microwave drying unit (power 6 kW, processing capacity 2 t / h) reduces the moisture content of the coal gangue to below 3% through a temperature control system (80±5℃), and the delay of slurry solidification is avoided.

[0058] S2: Construct a dynamic proportioning model, and adjust the mass ratio of coal gangue powder, fly ash, composite silicate cement, carbide slag, and desulfurization gypsum based on the rheological properties of the slurry and the grouting layer parameters. Specifically, this includes the following steps: Construct a dynamic proportioning model, and adjust the batching according to the following mass ratio: 50 parts coal gangue powder, 20 parts fly ash, 30 parts composite silicate cement, 8 parts carbide slag, and 10 parts desulfurization gypsum. Coal gangue powder serves as the aggregate skeleton, fly ash fills the pores, composite silicate cement provides cementitious strength, and carbide slag and desulfurized gypsum regulate setting time and expansion coefficient. A dual objective function of viscosity and porosity is established: when porosity > 25%, the viscosity setpoint is reduced to 1800 cP to enhance permeability; when porosity < 20%, the viscosity is increased to 2200 cP to prevent slurry loss. A fuzzy PID algorithm is used to process real-time data from the weighing sensor, dynamically compensating for fluctuations in raw material moisture content (compensation accuracy ±0.5%). Rheometer data is integrated via the OPC UA protocol, updating the mix proportion parameters every 15 seconds to ensure viscosity deviation ≤ ±5%. For every 5% increase in porosity, the fly ash proportion is increased by 3-5 parts to optimize particle size distribution, and the coal gangue particle size is adjusted to 0.5-1.2 mm. For every 2 parts increase in carbide slag content, 1.5 parts of desulfurized gypsum are added simultaneously to balance the Ca / Si molar ratio and prevent volume shrinkage cracking.

[0059] S3: Mixing multiple ingredients and adjusting stability; specifically including the following steps: stirring the adjusted ingredients with a mixer at a speed of 1000-1500 r / min for 10-20 min; ball milling the mixture to 200 mesh and then mixing it with water at a mass ratio of 0.85-0.95 to form a fluid slurry; setting up an online density meter and pH sensor, and adding material when the slurry specific gravity deviates from the set value by 1.65±0.05 g / cm³ to maintain slurry stability.

[0060] S4: Establish a three-dimensional spatial model of the borehole group and dynamically adjust the grouting sequence based on formation stress monitoring data; specifically, this includes the following steps: establishing a three-dimensional spatial model of the borehole group, dynamically adjusting the grouting sequence based on formation stress monitoring data, with high stress concentration areas filled first as the benchmark; adopting an aircraft-style borehole layout method, with a main borehole in the middle of the working face and branch boreholes on both sides, and boreholes in adjacent working faces connected at staggered levels to form a continuous grouting network, expanding the filling range. Directional drilling to the fractures below the key overburden layer, after grouting, forms a continuous support zone, inhibiting rock strata movement, and reducing surface subsidence by ≥70%.

[0061] S5: Construct a modular grouting station to implement three-stage pressure control for grouting; construct a modular grouting station that integrates a pretreatment unit, a mixing tank, and a high-pressure grouting pump, control the outlet pressure to 0-15 MPa, and achieve rapid movement through a sliding rail base; design a self-cleaning grouting pipeline with a polyurethane wear-resistant layer lining the pipe wall and a pulse backwashing device to prevent pipe blockage; install pressure sensors in the grouting pipeline to monitor grouting pressure in real time and control slurry concentration and grouting rate through PLC. Connect the modular grouting station to the Internet of Things monitoring platform through a 5G communication module to remotely diagnose and provide early warning for grouting pressure, flow, and slurry consistency parameters. Implement three-stage pressure control, including the following steps: use 8-10 MPa high-pressure rapid filling to fill the interlayer cavity in the early stage; switch to 5-6 MPa medium-pressure penetration and reinforcement in the middle stage; maintain 3-4 MPa stable pressure consolidation in the final stage, with a total duration of ≥2h. The pressure gradient grouting control strategy increases the utilization rate of grouting materials to 92% and reduces the surface subsidence coefficient to 0.08.

[0062] S6: Construct a sensing system to monitor the slurry diffusion radius and the strength of the consolidated body in real time. Deploy a distributed optical fiber sensing system with a spatial resolution of 1m to monitor the slurry diffusion radius and the strength of the consolidated body in real time, where the compressive strength ≥15MPa is used as a benchmark to generate a grouting efficiency thermal map, which guides parameter optimization. Deploy a distributed optical fiber sensing system along the grouting area to lay scattered enhanced optical fibers for continuous coverage and millimeter-level displacement monitoring. Based on the optical frequency domain reflection technology, the dynamic range is ≥120dB, there are 20 monitoring points per meter, temperature and strain data are collected synchronously, the sampling rate is controlled at 100Ksps, and the demand for capturing the transient process of slurry flow is met.

[0063] A double-channel distributed optical fiber strain monitoring system is adopted, a scattering enhanced optical fiber is arranged along the grouting area, a spatial resolution of 1 m is achieved, a millimeter level displacement monitoring of the slurry diffusion radius is supported (error ≤5 cm); based on the optical frequency domain reflection (OFDR) technology, a dynamic range ≥120 dB, 20 monitoring points per meter, temperature (-20~60℃) and strain (-5%~+3%) data are synchronously collected, a sampling rate 100Ksps, the slurry flow transient process capture demand is met; a slurry diffusion gradient model is constructed through the strain distribution data (spatial monitoring point density 20 points / m), the environmental vibration interference is eliminated through the Kalman filtering algorithm, the diffusion radius (accuracy ±0.3 m) is calculated in real time; the optical fiber strain-anti-pressure strength mapping relationship (R²≥0.95) is established, the alarm is triggered when the strain value reaches the critical threshold (corresponding to the anti-pressure strength ≥15 MPa), and the thermal expansion effect error is eliminated through the temperature compensation algorithm (compensation rate >90%); the optical time domain and optical frequency domain data are integrated, the Kriging interpolation algorithm is used to generate a three-dimensional thermal map, the slurry diffusion speed (m / min), the solidification strength distribution (MPa) and the temperature abnormal area (ΔT≥0.5℃) are dynamically displayed; according to the thermal map data density (≥500,000 points / minute), the transmission bandwidth is dynamically adjusted to 1.2 Gbps through the Ethernet interface, ensuring zero data packet loss; based on the strain rate threshold (≤0.1με / s), the grouting pressure is adjusted in real time, and the slurry over-diffusion or the solidification body cracking is prevented.

[0064] Example Three

[0065] According to Figure 1 As shown in the figure, the embodiment proposes a solid waste coal gangue disposal grouting settlement reduction method, including the following steps:

[0066] S1: crushing, screening and drying operations are performed on the coal gangue; specifically including the following steps: a crusher and a high-pressure water jet cleaning device are used to crush the coal gangue, the particle size is controlled to be ≤10 mm, a stirrer is used to realize forced mixing of the material and the cleaning liquid, and an ultrasonic oscillation device is used to remove surface impurities; a double-layer vibrating screen separation mechanism is set, the aperture is controlled to be 15 mm-8 mm, a photoelectric sensor is used to monitor the particle size distribution in real time, and closed-circuit crushing is performed on the super-particle size material; a microwave drying unit is configured, and the moisture content of the coal gangue is reduced to below 3%. The ultrasonic oscillation device (frequency 28 kHz) removes the surface clay attachments, the microwave drying unit (power 6 kW, processing capacity 2 t / h) reduces the moisture content of the coal gangue to below 3% through a temperature control system (80±5℃), and slurry solidification delay is avoided.

[0067] S2: Construct a dynamic proportioning model, and adjust the mass ratio of coal gangue powder, fly ash, composite silicate cement, carbide slag, and desulfurization gypsum based on the rheological properties of the slurry and the grouting layer parameters. Specifically, this includes the following steps: Construct a dynamic proportioning model, and adjust the batching according to the following mass ratio: 55 parts coal gangue powder, 25 parts fly ash, 35 parts composite silicate cement, 10 parts carbide slag, and 15 parts desulfurization gypsum. Coal gangue powder serves as the aggregate skeleton, fly ash fills the pores, composite silicate cement provides cementitious strength, and carbide slag and desulfurized gypsum regulate setting time and expansion coefficient. A dual objective function of viscosity and porosity is established: when porosity > 25%, the viscosity setpoint is reduced to 1800 cP to enhance permeability; when porosity < 20%, the viscosity is increased to 2200 cP to prevent slurry loss. A fuzzy PID algorithm is used to process real-time data from the weighing sensor, dynamically compensating for fluctuations in raw material moisture content (compensation accuracy ±0.5%). Rheometer data is integrated via the OPC UA protocol, updating the mix proportion parameters every 15 seconds to ensure viscosity deviation ≤ ±5%. For every 5% increase in porosity, the fly ash proportion is increased by 3-5 parts to optimize particle size distribution, and the coal gangue particle size is adjusted to 0.5-1.2 mm. For every 2 parts increase in carbide slag content, 1.5 parts of desulfurized gypsum are added simultaneously to balance the Ca / Si molar ratio and prevent volume shrinkage cracking.

[0068] S3: Mixing multiple ingredients and adjusting stability; specifically including the following steps: stirring the adjusted ingredients with a mixer at a speed of 1000-1500 r / min for 10-20 min; ball milling the mixture to 200 mesh and then mixing it with water at a mass ratio of 0.85-0.95 to form a fluid slurry; setting up an online density meter and pH sensor, and adding material when the slurry specific gravity deviates from the set value by 1.65±0.05 g / cm³ to maintain slurry stability.

[0069] S4: Establish a three-dimensional spatial model of the borehole group and dynamically adjust the grouting sequence based on formation stress monitoring data; specifically, this includes the following steps: establishing a three-dimensional spatial model of the borehole group, dynamically adjusting the grouting sequence based on formation stress monitoring data, with high stress concentration areas filled first as the benchmark; adopting an aircraft-style borehole layout method, with a main borehole in the middle of the working face and branch boreholes on both sides, and boreholes in adjacent working faces connected at staggered levels to form a continuous grouting network, expanding the filling range. Directional drilling to the fractures below the key overburden layer, after grouting, forms a continuous support zone, inhibiting rock strata movement, and reducing surface subsidence by ≥70%.

[0070] S5: Construct a modular grouting station to implement three-stage pressure control for grouting; construct a modular grouting station that integrates a pretreatment unit, a mixing tank, and a high-pressure grouting pump, control the outlet pressure to 0-15 MPa, and achieve rapid movement through a sliding rail base; design a self-cleaning grouting pipeline with a polyurethane wear-resistant layer lining the pipe wall and a pulse backwashing device to prevent pipe blockage; install pressure sensors in the grouting pipeline to monitor grouting pressure in real time and control slurry concentration and grouting rate through PLC. Connect the modular grouting station to the Internet of Things monitoring platform through a 5G communication module to remotely diagnose and provide early warning for grouting pressure, flow, and slurry consistency parameters. Implement three-stage pressure control, including the following steps: use 8-10 MPa high-pressure rapid filling to fill the interlayer cavity in the early stage; switch to 5-6 MPa medium-pressure penetration and reinforcement in the middle stage; maintain 3-4 MPa stable pressure consolidation in the final stage, with a total duration of ≥2h. The pressure gradient grouting control strategy increases the utilization rate of grouting materials to 92% and reduces the surface subsidence coefficient to 0.08.

[0071] S6: Construct a sensing system to monitor the slurry diffusion radius and the strength of the consolidated body in real time. Deploy a distributed optical fiber sensing system with a spatial resolution of 1m to monitor the slurry diffusion radius and the strength of the consolidated body in real time, where the compressive strength ≥15MPa is used as the benchmark to generate a grouting efficiency thermal map, which guides parameter optimization. Deploy a distributed optical fiber sensing system along the grouting area to lay scattered enhanced optical fibers for continuous coverage and millimeter-level displacement monitoring. Based on the optical frequency domain reflection technology, the dynamic range is ≥120dB, there are 20 monitoring points per meter, temperature and strain data are collected synchronously, the sampling rate is controlled at 100Ksps, and the demand for capturing the transient process of slurry flow is met.

[0072] A double-channel distributed optical fiber strain monitoring system is adopted, a scattering enhanced optical fiber is arranged along the grouting area, a continuous coverage with a spatial resolution of 1 m is realized, millimeter level displacement monitoring (error ≤5 cm) of the slurry diffusion radius is supported; based on the optical frequency domain reflection (OFDR) technology, a dynamic range ≥120 dB, 20 monitoring points per meter, temperature (-20~60℃) and strain (-5%~+3%) data are synchronously collected, a sampling rate 100Ksps, the transient process capture requirement of the slurry flow is met; a slurry diffusion gradient model is constructed through the strain distribution data (spatial monitoring point density 20 points / m), environmental vibration interference is eliminated in combination with the Kalman filtering algorithm, the diffusion radius (precision ±0.3 m) is calculated in real time; a mapping relationship (R²≥0.95) of the optical fiber strain and the compressive strength is established, an alarm is triggered when the strain value reaches a critical threshold (corresponding to the compressive strength ≥15 MPa), and a thermal expansion effect error (compensation rate >90%) is eliminated through a temperature compensation algorithm; integrated optical time domain and optical frequency domain data, a three-dimensional thermal map is generated through the Kriging interpolation algorithm, the slurry diffusion speed (m / min), the consolidation strength distribution (MPa) and the temperature abnormal area (ΔT≥0.5℃) are dynamically displayed; according to the data density (≥500,000 points / minute) of the thermal map, the transmission bandwidth is dynamically adjusted to 1.2Gbps through the Ethernet interface, ensuring zero packet loss of data; based on the strain rate threshold (≤0.1με / s), the grouting pressure is adjusted in real time, and the slurry overdiffusion or the cracking of the solidified body is prevented.

[0073] According to the embodiment one, the embodiment two and the embodiment three, it can be concluded that the slurry prepared by the components in the quality ratio of 45-55 parts of coal gangue powder, 15-25 parts of fly ash, 25-35 parts of composite portland cement, 5-10 parts of carbide slag and 5-15 parts of desulfurization gypsum has good fluidity and stability.

[0074] Verification example:

[0075]

[0076] The solid waste coal gangue treatment grouting subsidence reduction method adjusts the material quality ratio according to a dynamic proportioning model, takes coal gangue as a core raw material, combines with industrial waste residues such as calcium carbide slag, realizes that the utilization rate of solid waste is greater than or equal to 95%, reduces the cement consumption, meanwhile, an online densimeter and a pH sensor are arranged, material is supplemented according to the slurry specific gravity set value, and the slurry stability is maintained. The material and the cleaning liquid are forcedly mixed through a stirrer, surface impurities are removed through an ultrasonic oscillation device, the particle grading is monitored in real time through a double-layer vibrating screen separation mechanism in cooperation with a photoelectric sensor, and a microwave drying unit is configured to dry, so that the coal gangue quality and the utilization rate are improved. In addition, the three-stage pressure control is implemented for grouting, the dynamic grouting technology based on pressure feedback is combined with drilling network optimization, the filling uniformity and efficiency are improved, the hysteresis of traditional manual regulation is avoided, the distributed optical fiber sensing system is deployed, the slurry diffusion radius and the solidified body strength are monitored in real time, the grouting efficiency thermodynamic diagram is generated, parameter optimization is guided, and the surface subsidence reduction rate is greater than or equal to 70%.

[0077] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A grouting method for reducing sedimentation in the treatment of solid waste coal gangue, characterized in that, Includes the following steps: S1: Crushing, screening, and drying of coal gangue; specifically including the following steps: crushing the coal gangue using a crusher and a high-pressure water jet cleaning device to control its particle size ≤10mm; using a mixer to achieve forced mixing of the material and the cleaning liquid; and using an ultrasonic oscillation device to remove surface impurities; setting up a double-layer vibrating screen mechanism to control the aperture 15mm-8mm; using a photoelectric sensor to monitor the particle size distribution in real time; and implementing closed-loop circulation crushing for oversized materials; and configuring a microwave drying unit to reduce the moisture content of the coal gangue to below 3%. S2: Construct a dynamic proportioning model and adjust the mass ratio of coal gangue powder, fly ash, composite silicate cement, carbide slag, and desulfurization gypsum based on the rheological properties of the slurry and the parameters of the grouting layer. S3: Mix multiple ingredients and adjust their stability; S4: Establish a three-dimensional spatial model of the borehole group and dynamically adjust the grouting sequence based on formation stress monitoring data; specifically, the following steps are included: establish a three-dimensional spatial model of the borehole group and dynamically adjust the grouting sequence based on formation stress monitoring data, with the high stress concentration area being filled first as the benchmark; adopt the aircraft-style borehole layout method, with the main borehole in the middle of the working face and branch boreholes on both sides, and the boreholes of adjacent working faces connected at staggered levels to form a continuous grouting network and expand the filling range; S5: Construct a modular grouting station and implement three-stage pressure control for grouting; S6: Construct a sensing system to monitor the slurry diffusion radius and the strength of the solidified body in real time.

2. The grouting and sedimentation reduction method for solid waste coal gangue disposal according to claim 1, characterized in that: S2 includes the following steps: A dynamic proportioning model was constructed, based on the rheological properties of the grout (viscosity 1500-2500 cP) and the porosity of the grouting layer (porosity 15-35%), and the proportioning was adjusted by a PLC controller. Adjust the following mass ratios: 45-55 parts coal gangue powder, 15-25 parts fly ash, 25-35 parts composite silicate cement, 5-10 parts calcium carbide slag, and 5-15 parts desulfurized gypsum.

3. The grouting method for reducing sedimentation in the disposal of solid waste coal gangue according to claim 1, characterized in that: S3 includes the following steps: The adjusted ingredients are mixed using a mixer at a speed of 1000-1500 r / min for 10-20 min. After stirring, the mixture is ball-milled to 200 mesh and then mixed with water at a mass ratio of 0.85-0.95 to form a fluid slurry. An online density meter and pH sensor are installed. When the slurry specific gravity deviates from the set value of 1.65±0.05g / cm³, additional material is added to maintain slurry stability.

4. The grouting and sedimentation reduction method for solid waste coal gangue disposal according to claim 1, characterized in that: In S5, a modular grouting station is constructed, integrating a pretreatment unit, a mixing tank and a high-pressure grouting pump, controlling the outlet pressure to 0-15MPa, and achieving rapid movement through a sliding rail base. The design incorporates a self-cleaning grouting pipeline with a polyurethane wear-resistant layer lining the inner wall and a pulse backflushing device to prevent pipe blockage. Pressure sensors are installed in the grouting pipeline to monitor the grouting pressure in real time, and the grout concentration and grouting rate are controlled by PLC.

5. The grouting method for reducing sedimentation in the disposal of solid waste coal gangue according to claim 4, characterized in that: The modular grouting station is connected to the Internet of Things monitoring platform via a 5G communication module to remotely diagnose and provide early warnings of grouting pressure, flow rate, and grout consistency parameters.

6. The grouting method for reducing sedimentation in the disposal of solid waste coal gangue according to claim 5, characterized in that: In step S5, implementing three-stage pressure control includes the following steps: Initially, high pressure of 8-10 MPa was used to rapidly fill the delamination cavity; Mid-term switch to 5-6MPa medium-pressure permeability reinforcement; The pressure is maintained at 3-4 MPa for consolidation in the final stage, with an overall duration of ≥2 hours.

7. The grouting method for reducing sedimentation in the disposal of solid waste coal gangue according to claim 1, characterized in that: In S6, a distributed optical fiber sensing system with a spatial resolution of 1m is deployed to monitor the grout diffusion radius and the strength of the solidified body in real time. The system generates a grouting efficiency thermal map based on a compressive strength of ≥15MPa, thereby guiding parameter optimization.

8. The grouting method for reducing sedimentation in the disposal of solid waste coal gangue according to claim 7, characterized in that: A distributed optical fiber sensing system is deployed, with scattering-enhancing optical fibers laid along the grouting area for continuous coverage and millimeter-level displacement monitoring. Based on optical frequency domain reflection technology, the dynamic range is ≥120dB, with 20 monitoring points per meter, simultaneously collecting temperature and strain data, and controlling the sampling rate to 100Ksps to meet the requirements for capturing transient processes of grout flow.

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