Caving zone filling method based on solid-liquid-gas three-waste synergistic mineralization

Abstract

The invention discloses a caving zone filling method based on solid-liquid-gas three-waste synergistic mineralization, and relates to the technical field of mine filling. Comprising the following steps that goaf grouting filling parameters are determined through a multi-source data fusion analysis method; the filling material is prepared by taking mining area solid wastes, mining area liquid wastes and gas wastes as basic materials; filling materials are injected into the residual space of the caving zone of the goaf of the underground working face through a ground grouting filling system, the loose gangue structure in the goaf is cemented, and a filling body is formed; the method realizes the utilization of solid-liquid-gas three wastes in the mine, achieves the purposes of reducing ground surface settlement, protecting water resources and the like, and accords with the low-carbon and high-efficiency mineral development concept.

Description

Technical Field

[0001] The invention relates to the field of mine filling, and in particular to a collapse zone filling method based on the coordinated mineralization of solid, liquid and gas wastes. Background Art

[0002] Coal resources occupy a core position in my country's energy system, accounting for a high proportion of primary energy production and consumption, and are a key force in promoting national economic construction and social progress. For a long time in the future, the energy structure dominated by coal will continue. However, while the large-scale development and utilization of coal resources has created huge economic value, it has also caused many serious environmental problems.

[0003] In the process of coal mining, washing and power generation, a large amount of solid waste is generated, such as coal gangue, fly ash, slag, etc. These wastes not only occupy a large amount of valuable land resources, but also may cause spontaneous combustion and leaching due to long-term stacking, causing pollution to the surrounding soil, water and atmospheric environment. At the same time, the flue gas emitted by power plants contains a large amount of greenhouse gases such as carbon dioxide, which aggravates global climate change; the high-salt mine water generated during coal mining, if directly discharged without effective treatment, will pollute underground and surface water resources and destroy the ecological balance.

[0004] In coal mining activities, the problem of ground subsidence caused by traditional mining methods is particularly prominent. This will not only damage surface buildings and threaten the safety of life and property of residents, but also destroy the surface ecological environment, causing a series of ecological degradation phenomena such as vegetation destruction and land desertification. As an ecological protection mining method, backfill mining technology can effectively control surface subsidence and overburden movement, and has significant advantages in mining area ecological restoration, solid waste treatment and mine water resource utilization.

[0005] With the continuous increase in carbon dioxide emissions, fly ash generation, and high-salt mine water extraction, traditional treatment methods can no longer meet the needs of environmental protection and sustainable development. Summary of the invention

[0006] The purpose of the present invention is to provide a collapse zone filling method based on the coordinated mineralization of solid, liquid and gas wastes.

[0007] To achieve the above object, the present invention provides the following technical solution: a method for filling a collapsed zone based on the coordinated mineralization of solid, liquid and gas wastes, comprising the following steps:

[0008] Determine the grouting filling parameters of goaf area through multi-source data fusion analysis method;

[0009] Filling materials prepared with mining solid waste, mining liquid waste and gaseous waste as basic materials;

[0010] The filling material is injected into the residual space of the collapsed zone in the goaf of the underground working face through the ground grouting filling system to cement the loose gangue structure in the goaf to form a filling body.

[0011] Furthermore, the solid waste in the mining area includes fly ash, coal gangue and slag, the liquid waste in the mining area includes high-salt mine water, and the gaseous waste includes power plant flue gas after desulfurization treatment.

[0012] Furthermore, the ground grouting filling system includes an aggregate storage system for storing solid waste in mining areas, an aggregate weighing and metering system for weighing solid waste in each mining area, a solid waste-based slurry preparation system for mixing liquid waste in mining areas with solid waste in mining areas, a carbon dioxide mineralization reaction system for introducing gaseous waste into the solid waste-based slurry for reaction, and a grouting system for injecting filling materials into the collapse zone.

[0013] Furthermore, the aggregate storage system includes an ash storage tank for storing fly ash, a gangue powder tank for storing coal gangue powder, and a slag tank for storing slag;

[0014] The aggregate weighing and metering system comprises a screw feeding conveyor for transporting raw materials in the aggregate storage system and a screw metering scale for weighing the weight of the raw materials transported by the screw feeding conveyor;

[0015] The solid waste-based slurry preparation system includes a primary closed stirring tank for stirring various raw materials, a mine water reservoir for storing liquid waste in the mining area, and a transfer device for transferring the solid waste-based slurry after mixing and stirring;

[0016] The carbon dioxide mineralization reaction system includes a secondary closed stirring tank for further stirring the raw materials and a waste gas temporary storage tank for storing gaseous waste;

[0017] The grouting system comprises a grouting pump, a pressure gauge and a grouting borehole, and the grouting pump injects the filling material into the collapse zone through the grouting borehole.

[0018] Furthermore, the method for determining the grouting filling parameters of the goaf is specifically as follows:

[0019] Based on the statistical analysis of geological exploration drilling column data, the occurrence status of the top rock layer in the mining area and the physical and mechanical characteristic parameters of different overburden layers are clarified;

[0020] Use numerical simulation software to establish a geological model of the mining area, simulate the deformation, stress distribution and damage of the rock formation during mining based on the rock mechanics parameters, geological structure and other information of the mining area, analyze the simulation results, and determine the location of the key layer that plays a key role in controlling the movement and stability of the rock formation;

[0021] Through laboratory tests, the conveying performance of the filling material is tested and the rheological characteristic parameters of the slurry are obtained;

[0022] According to the buried depth and mining thickness of coal seams, combined with the analysis of the lithological characteristics of the roof, the final hole position of the drilling hole is determined;

[0023] The calculation model of slurry diffusion radius is constructed by integrating the terminal hole layer parameters and the slurry rheological characteristic parameters;

[0024] Based on the coupling analysis of the effective diffusion range of slurry and the mechanical parameters of key overburden strata, an optimization model for the spatial arrangement of boreholes along the strike and dip of the coal seam is established to determine the grouting filling parameters.

[0025] Furthermore, the hole depth of the grouting borehole is calculated by the following formula:

[0026]

[0027] Where: H—depth of grouting drilling hole; H m —Deepness of coal seam; M—mining thickness; β, γ—stratum lithology adjustment coefficients; σ—mean error.

[0028] Furthermore, the grouting pressure value range satisfies the following formula:

[0029] P 孔底 ≥P≥P 地层

[0030] P 孔底 =P 孔口 +1.2Hρ1

[0031] P 地层 =Hρ

[0032] Where: P—grouting filling pressure; P 孔底 —The penetration pressure of the safety isolation rock layer at the bottom of the grouting hole; P 地层 —Natural pressure of the stratum above the grouting filling layer; P 孔口 —Grouting pressure at the top of the grouting borehole; H—hole depth of the final hole layer; ρ1—specific gravity of the filling slurry; ρ—comprehensive specific gravity of the strata above the grouting filling layer.

[0033] Furthermore, the number of the grouting boreholes is multiple, and the spacing between two adjacent grouting boreholes along the strike direction is calculated by the following formula:

[0034] W1=1.75k j R k

[0035] Where: W1—hole spacing between adjacent boreholes along the strike; k j —Safety factor; R k —Slurry diffusion radius.

[0036] Furthermore, the spacing between two adjacent grouting boreholes along the dip direction is calculated by the following formula:

[0037]

[0038] Where: W2 is the distance between adjacent boreholes along the dip; h is the thickness of the key layer; E is the elastic modulus of the key layer; v is the Poisson's ratio of the key layer; L is the dip length of the goaf.

[0039] Also provided is a collapse zone filling material based on the coordinated mineralization of solid, liquid and gas wastes, comprising the following raw materials in parts by weight: 30-45 parts of fly ash, 10-30 parts of gangue powder, 5-10 parts of slag, 5-10 parts of alkaline additives, 15-50 parts of high-salt mine water and gaseous waste; the salt ion concentration in the high-salt water is not less than 1000 mg / L, and the alkaline additive is a mixture of sodium hydroxide and sodium silicate in a weight ratio of (30-50):(50-70).

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. The present invention combines solid waste (fly ash, coal gangue, slag), liquid waste (high-salt mine water), and gaseous waste (power plant flue gas) to prepare mining area solid waste liquid and gas filling materials, thereby realizing the recycling of mining area waste solid, liquid, and gas, reducing the pollution of waste to the environment, reducing the cost of waste treatment, and saving a lot of funds for purchasing traditional filling materials, thereby improving the comprehensive utilization efficiency of resources;

[0042] 2. The present invention utilizes high-salt mine water to participate in the preparation of filling materials, thereby avoiding the pollution of underground and surface water resources caused by direct discharge of high-salt mine water, and realizing the resource utilization of mine water resources;

[0043] 3. The present invention determines the grouting filling parameters of the goaf through a multi-source data fusion analysis method, and can be flexibly adjusted according to the geological conditions, mining conditions, etc. of different mining areas. It has strong adaptability and can be widely used in various coal mining areas, providing effective technical support for green coal mining under different conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the ground grouting filling system;

[0045] Figure 2 This is a schematic diagram of the drilling plan layout;

[0046] Figure 3 Schematic diagram of drilling profile arrangement.

[0047] In the figure: 1- ash storage tank; 2- gangue powder tank; 3- slag tank; 6- primary closed mixing tank; 7- mine water storage tank; 8- transfer device; 9- secondary closed mixing tank; 10- waste gas temporary storage tank; 11- grouting pump, 12- pressure gauge; 13- grouting drilling hole. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0049] like Figure 1 , Figure 2 and Figure 3 As described above, in order to solve the problem of green disposal of solid, liquid and gas wastes, a method for filling collapsed zones with coordinated mineralization of solid, liquid and gas wastes in mining areas is proposed.

[0050] Collect solid waste from the mining area, such as fly ash, coal gangue, and slag, to ensure that their particle size meets the material preparation requirements; collect liquid waste from the mining area, that is, high-salt mine water with a salt ion concentration of not less than 1000 mg / L; reserve the flue gas from the power plant after desulfurization and purification as gaseous waste. Alkaline additives are mixed in a weight ratio of 25:75 between sodium hydroxide and sodium silicate for standby use.

[0051] According to the weight ratio, 40% of fly ash, 20% of gangue powder, 8% of slag, 8% of alkaline additive and 24% of mine water are accurately weighed for preparation; the fly ash in the ash storage tank 1, the gangue powder in the gangue powder tank 2 and the slag in the slag tank 3 are respectively fed to the spiral metering scale through the spiral feeding conveyor at the bottom of the pipe for accurate weighing to obtain a solid waste-based mixture; the weighed mixture is sent to the primary closed mixing tank 6, the corresponding proportion of mine water is pumped into the mine water reservoir 7, and the alkaline additive is added and fully stirred to obtain a preliminary slurry; the transfer device 8 (for example The slurry is transferred to the secondary closed mixing tank 9 through a pipeline or a tank truck, and the desulfurized and purified flue gas from the power plant in the waste gas temporary storage tank 10 is pressurized and passed into the secondary closed mixing tank 9, and is fully mixed and stirred with the slurry to finally obtain the material for filling the collapsed zone; the prepared filling material is pumped into the pipeline through a grouting pump 11, and the grouting pressure is monitored by a pressure gauge 12, and the underground collapsed zone is filled through a filling borehole 13, and the filling material is injected into the residual space of the collapsed zone of the goaf of the underground working face to cement the loose gangue structure in the goaf to form a filling body with certain strength and stability to support the overlying mining strata and realize green, safe and low-carbon mining.

[0052] It should be noted that the microscopic reaction product system of the filling material includes: calcium carbonate, amorphous silica gel, hydrated calcium silicate gel and calcium aluminum silicate gel;

[0053] The formation of silica gel originates from the chemical reaction between carbon dioxide and silicate minerals and hydrated calcium silicate. This process is accompanied by the simultaneous formation of calcium carbonate. The formation of calcium carbonate involves three key reaction pathways: the reaction of carbon dioxide with hydrated calcium silicate, the reaction of carbon dioxide with calcium hydroxide (a byproduct of slag hydration), and the mineralization reaction of carbon dioxide with tricalcium silicate.

[0054] Calcium carbonate improves density through the pore-filling effect, and silica gel forms a three-dimensional network structure in the system. Its surface hydroxyl groups chemically bond with the hydration products, enhancing the interface connection through the "secondary bonding effect". The hydrated calcium silicate gel and calcium aluminum silicate gel synergistically constitute the skeleton of the microscopic system.

[0055] Analyze the columnar data of geological exploration boreholes in the coal mining area to obtain the occurrence conditions of the roof rock strata in the mining area, including the number of layers, thickness, lithology and other information of the rock strata, and determine the physical and mechanical parameters of each overburden stratum, such as elastic modulus, Poisson's ratio, compressive strength, etc.; use numerical simulation software (such as FLAC3D, UDEC, etc.) to establish a geological model of the mining area, and use the rock mechanical parameters, geological structure and other information of the mining area to simulate the deformation, stress distribution and damage of the rock strata during the mining process, analyze the simulation results (displacement cloud map of the rock strata, stress concentration area, etc.), and determine the position of the key layer that plays a key role in controlling the movement and stability of the rock strata; test the transportation performance of the filling material through laboratory experiments to obtain the rheological parameters of the slurry; determine the final hole position of the borehole based on the burial depth and mining thickness of the coal seam, combined with the analysis of the lithological characteristics of the roof; construct a slurry diffusion radius calculation model by combining the final hole position parameters and the slurry rheological parameters; establish a borehole spatial layout optimization model along the strike and dip of the coal seam based on the coupling analysis of the effective diffusion range of the slurry and the mechanical parameters of the key overburden strata. Then, the collapsed roof morphology of the coal seam goaf area is detected through drilling or geophysical exploration, and the collapse of the roof rock strata in the goaf area is comprehensively analyzed to determine the position relationship of the key layers in the mining area.

[0056] According to the buried depth and thickness of the coal seam combined with the lithological characteristics of the roof strata, the final hole position of the grouting borehole 13 is determined; the hole depth of the final hole position is calculated by the following formula:

[0057] Where: H—hole depth of the final hole layer; H m —Deepness of coal seam; M—mining thickness; β, γ—stratum lithology adjustment coefficient; σ—mean error;

[0058] The grouting pressure is determined according to the pressure of each layer of the grouting borehole 13, the final hole layer and the slurry transportation characteristic parameters; the borehole grouting pressure should not be less than the natural ground pressure of the stratum above the grouting filling layer to ensure surface stability.

[0059] The grouting pressure range is given by the formula P 地层 ≤P≤P孔底 Calculate, where P 孔底 =P 孔口 +1.2Hρ1,P 地层 =Hρ, where: P—grouting filling pressure; P 孔底 —The penetration pressure of the safety isolation rock layer at the bottom of the grouting hole; P 地层 —Natural pressure of the stratum above the grouting filling layer; P 孔口 — Grouting pressure at the top of the grouting borehole; H—hole depth of the final hole layer; ρ1—specific gravity of the filling slurry; ρ—comprehensive specific gravity of the strata above the grouting filling layer;

[0060] The slurry diffusion radius is determined according to the physical property parameters of the filling material; the slurry diffusion radius is calculated by the following formula:

[0061] Where: R k —slurry diffusion radius; k—coefficient related to slurry and rock mass characteristics; P—grouting filling pressure; t—grouting time; μ—slurry dynamic viscosity; R—slurry flow resistance; α—slurry compression coefficient;

[0062] According to the slurry diffusion radius, the hole spacing between adjacent boreholes along the strike is determined; the hole spacing W1 between adjacent boreholes along the strike is calculated by the following formula: W1 = 1.75k j R k ,

[0063] Where: W1—hole spacing between adjacent boreholes along the strike; k j —Safety factor; R k —Slurry diffusion radius;

[0064] According to the physical and mechanical property parameters of the key strata overlying the mining area, the hole spacing W2 between adjacent boreholes along the dip is determined; it is calculated by the following formula:

[0065] Where: W2—hole spacing between adjacent boreholes along the dip; h—key layer thickness; E—key layer elastic modulus; v—key layer Poisson’s ratio; L—goaf dip length;

[0066] According to the parameters determined above, start the ground grouting filling system. Ensure the normal operation of the aggregate storage system, aggregate weighing and metering system, solid waste-based slurry preparation system and carbon dioxide mineralization reaction system, and accurately prepare and transport filling materials.

[0067] Drilling construction is carried out according to the determined hole spacing and final hole layer. After the drilling is completed, the prepared slurry is pressurized and transported through the filling pipeline by a filling pump and injected into the residual space of the goaf collapse zone of the underground working face; during the grouting process, the grouting pressure and grouting time are strictly controlled to ensure that the slurry can diffuse and cement the loose structure in the goaf according to the design requirements.

[0068] During and after the filling process, the filling effect is monitored; by observing the displacement changes of the overlying rock strata, the strength development of the filling body and other indicators, it is evaluated whether the filling effect has met the expectations; if the filling effect is found to be unsatisfactory, the filling parameters are adjusted in time or appropriate remedial measures are taken.

[0069] Through the above specific implementation methods, the present invention utilizes the solid, liquid and gas wastes in the mining area as filling raw materials, realizes the effective filling of the collapse zone, supports the overlying rock strata, and achieves the purpose of green, safe and low-carbon mining.

[0070] In addition, an embodiment of the present invention further provides a collapse zone filling material based on the coordinated mineralization of solid, liquid and gas wastes, comprising the following raw materials in parts by weight: 30-45 parts of fly ash, 10-30 parts of gangue powder, 5-10 parts of slag, 5-10 parts of alkaline additives, 15-50 parts of high-salt mine water and gaseous waste; the salt ion concentration in the high-salt water is not less than 1000 mg / L, and the alkaline additive is a mixture of sodium hydroxide and sodium silicate in a weight ratio of (30-50):(50-70).

[0071] It should be noted that the particle size d of the fly ash is 煤 ≤200μm, the particle size of the slag d 渣 ≤150μm, the particle size of the gangue powder is 矸 ≤50mm; the fly ash is low-calcium fly ash, and the CaO content in the fly ash is ≤5.00%.

[0072] The preparation method of the filling material is as follows: 30-45 parts of fly ash, 10-30 parts of gangue powder, and 5-10 parts of slag are placed in a crusher for crushing and then sieved to obtain a particle size of d 煤 Fly ash ≤200μm, particle size d 矸 Gangue powder and particle size d ≤50mm 渣 ≤150 μm slag, and mixing and stirring them to obtain a solid mixture;

[0073] Mix 5-10 parts of alkaline additive and 15-50 parts of high water at a temperature of 20-25° C. and a pressure of 101.325 kPa to obtain an aqueous solution of the alkaline additive;

[0074] The aqueous solution of the alkaline additive and the solid mixture are mixed and stirred, and gaseous waste is introduced during the stirring process. The amount of gaseous waste introduced is determined according to the CO2 content in the waste gas and the slurry volume of the aqueous solution of the alkaline additive and the solid mixture. The amount of CO2 in the waste gas required to be introduced per cubic meter of slurry is 5000L / h-50000L / h, and the ventilation time of the waste gas is 60min. After stirring, the mining area waste solid-liquid-gas is obtained to prepare high-salt water resistant weakened filling material.

[0075] Example 1

[0076] Weigh 45 parts of fly ash, 10 parts of gangue powder, 10 parts of slag, 5 parts of alkaline additives, and 30 parts of high-salt mine water. Put the fly ash, gangue powder, and slag into a crusher for crushing and sieving to obtain a particle size of d 煤 Fly ash ≤200μm, particle size d 矸 Gangue powder and particle size d ≤50mm 渣 For slag with a diameter of ≤150 μm, an alkaline additive is dissolved in high-salt mine water and stirred for 20 minutes to obtain an alkaline activator solution.

[0077] The alkaline additive solution, fly ash, gangue powder and slag are respectively added to the primary sealed stirring tank 6 for stirring evenly to obtain a mixed slurry, and the mixed slurry is transferred to the secondary sealed stirring tank 9 through the transfer device 8. At a temperature of 20-25°C and a pressure of 101.325 kPa, gaseous waste is introduced while stirring for 60 minutes. The amount of CO2 introduced into each cubic meter of slurry is 5000L / h-50000L / h, and the high-salt water resistant weakened filling material is prepared from mining waste solid, liquid and gas.

[0078] Detection of coal seam burial depth H in mining area m The mining thickness M is 300m, and the mining thickness M is 5m. According to the lithology of the roof strata, β=6.2,γ=32,σ=4.6,P 孔口 =2.5MPa, H=292m, ρ1=12kN / m3, ρ=20kN / m3, k=0.5, t=3h=10800s, μ=0.05Pa·s, R=0.1Pa·s, α=0.01, h=12m, E=3000MPa, v=0.25, L=220m.

[0079] Through the formula The hole depth H of the final hole layer calculated from the above data is 292m;

[0080] Through the formula P 孔底 =2.5+1.2×292×12÷1000=6.70MPa, P 地层=292×20÷1000=5.84MPa, the grouting pressure should satisfy 5.84MPa≤P≤6.70MPa;

[0081] Take P = 6MPa, and use the formula Calculate R k =126.87m;

[0082] Take k j =1.5, through the formula W1 = 1.75k j R k We get W1 = 333m;

[0083] According to the above data and formula Calculation shows that 202.55m≤W2≤220m.

[0084] The W1, W2 and H obtained above are used to determine the hole depth and spacing position of the filling boreholes, and the filling material is grouted into the mined area using a grouting pump with the calculated grouting pressure.

[0085] Example 2

[0086] The difference from Example 1 is that 40 parts of fly ash, 15 parts of gangue powder, 10 parts of slag, 5 parts of alkaline additives, and 30 parts of high-salt mine water are weighed.

[0087] Example 3

[0088] The difference from Example 1 is that 40 parts of fly ash, 10 parts of gangue powder, 10 parts of slag, 5 parts of alkaline additives, and 35 parts of high-salt mine water are weighed.

[0089] Example 4

[0090] The difference from Example 1 is that 45 parts of fly ash, 15 parts of gangue powder, 10 parts of slag, 5 parts of alkaline additives, and 25 parts of high-salt mine water are weighed.

[0091] Test Example 1

[0092] The mixed mortar prepared in Examples 1-4 was poured into a cylindrical mold with silicone oil brushed inside, placed on a vibrator for 5 minutes, demolded after 24 hours, and placed in a curing box with a temperature of 20°C and a humidity of 95% for 56 days. After the curing, the sample was soaked in pure water for 7 days, and then air-dried at a constant temperature of 45°C for 24 hours to obtain a sample with a simulated filling effect.

[0093] Finally, the uniaxial compressive strength of the samples before and after immersion, the pH value of the immersion solution, and the concentration of metal ions leached from the samples were tested.

[0094] Test Example 2

[0095] The mixed mortar prepared in Example 1 was poured into a cylindrical mold with silicone oil applied inside, and placed on a vibrator for 5 minutes. After 24 hours, the mold was removed and placed in a curing box at a temperature of 20°C and a humidity of 95% for 56 days. + The concentration is 300mg / L, Ca 2+ Concentration 300mg / L, Mg 2+ The concentration is 300mg / L, Cl - Concentration is 400mg / L, SO4 2- The samples were immersed in a corrosion solution with a concentration of 400 mg / L for 7 days and then air-dried at a constant temperature of 45°C for 24 hours to obtain samples with simulated filling effects.

[0096] Finally, the uniaxial compressive strength of the samples before and after corrosion, the penetration depth and pH value of the ions in the corrosion solution, and the concentration of metal ions leached from the samples were tested.

[0097] Test Example 3

[0098] The mixed mortar prepared in Example 2 was poured into a cylindrical mold with silicone oil applied inside, placed on a vibrator for 5 minutes, demoulded after 24 hours, and placed in a curing box at a temperature of 20°C and a humidity of 95% for 56 days. + The concentration is 300mg / L, Ca 2+ Concentration 300mg / L, Mg 2+ The concentration is 300mg / L, Cl - Concentration is 400mg / L, SO4 2- The samples were immersed in a corrosion solution with a concentration of 400 mg / L for 7 days and then air-dried at a constant temperature of 45°C for 24 hours to obtain samples with simulated filling effects.

[0099] Finally, the uniaxial compressive strength of the samples before and after corrosion, the penetration depth and pH value of the ions in the corrosion solution, and the concentration of metal ions leached from the samples were tested.

[0100] Test Example 4

[0101] The mixed mortar prepared in Example 3 was poured into a cylindrical mold with silicone oil applied inside, placed on a vibrator for 5 minutes, demoulded after 24 hours, and placed in a curing box at a temperature of 20°C and a humidity of 95% for 56 days. + The concentration is 300mg / L, Ca 2+ Concentration 300mg / L, Mg 2+ The concentration is 300mg / L, Cl - Concentration is 400mg / L, SO4 2-The samples were immersed in a corrosion solution with a concentration of 400 mg / L for 7 days and then air-dried at a constant temperature of 45°C for 24 hours to obtain samples with simulated filling effects.

[0102] Finally, the uniaxial compressive strength of the samples before and after corrosion, the penetration depth and pH value of the ions in the corrosion solution, and the concentration of metal ions leached from the samples were tested.

[0103] Test Example 5

[0104] The mixed mortar prepared in Example 4 was poured into a cylindrical mold with silicone oil applied inside, placed on a vibrator for 5 minutes, demoulded after 24 hours, and placed in a curing box at a temperature of 20°C and a humidity of 95% for 56 days. + The concentration is 300mg / L, Ca 2+ Concentration 300mg / L, Mg 2+ The concentration is 300mg / L, Cl - Concentration is 400mg / L, SO4 2- The samples were immersed in a corrosion solution with a concentration of 400 mg / L for 7 days and then air-dried at a constant temperature of 45°C for 24 hours to obtain samples with simulated filling effects.

[0105] Finally, the uniaxial compressive strength of the samples before and after corrosion, the penetration depth and pH value of the ions in the corrosion solution, and the concentration of metal ions leached from the samples were tested.

[0106] The uniaxial compressive strength test of the filling materials after curing in test examples 1-5 was carried out before and after corrosion. The UCS test was carried out on the samples using a WDW-300 electronic universal testing machine in accordance with the national standard (GB / T1761-2021). The samples were loaded at a constant speed of 1 mm / min, and the peak stress and displacement were recorded. The test was repeated three times, and the results are shown in Table 1.

[0107] The penetration depth test was conducted by dissolving powder samples at depths of 5, 10, 15, 16, 17, 18, 19 and 20 mm in tap water and leaving them for 48 hours, after which the collected powder samples were analyzed using a Hitachi DR UV-3900 UV-visible spectrophotometer. The results are shown in Table 1.

[0108] To test the pH value, insert the pH meter calibrated with the standard buffer solution into the solution to be tested, gently stir the solution to allow the electrode to fully contact the solution, and read and record the pH value after the pH meter display value stabilizes. The results are shown in Table 2.

[0109] The leached ion concentration test was carried out, and the solution after immersion was subjected to Cu 2+ by inductively coupled plasma optical emission spectrometry (ICP-OES) or ion chromatography (ICP-OES). 2+ 、Zn2+ 、Al 3+ 、As 3+ , Hg 2+ 、Se 4+ Quantitative analysis. The results are shown in Table 2.

[0110] Table 1 Sample test results

[0111]

[0112] Table 2 Corrosive solution test results

[0113]

[0114] The above results show that the compressive strength of the filling material before being corroded by high-salt mine water is greater than 6.0MPa, and the compressive strength after corrosion is greater than 5.5MPa. The water weakening rate of the compressive strength before and after corrosion is higher than 90%. The pH value of the filling material after being corroded by high-salt mine water is 6.8-7.6, which is within the range of 6.5-8.5. The filling material is corroded by high-salt mine water to leach Cu 2+ 0.53-0.76 mg / L, not higher than 1.00 mg / L; Zn 2+ 0.29-0.49mg / L, not higher than 1.00mg / L; Al 3+ 0.007-0.090mg / L, not higher than 0.200mg / L; As 3+ 0.001-0.006mg / L, not higher than 0.01mg / L; Hg 2+ 0.0002-0.0005mg / L, not higher than 0.001mg / L; Se 4+ It is 0.002-0.004mg / L, not higher than 0.01mg / L.

[0115] Compared with Test Example 1, which was not prepared with high-salt mine water and the immersion solution was pure water, the water weakening rates of the filling samples in Test Examples 2-5, which were prepared with high-salt mine water, were significantly higher than those in Test Example 1, indicating that high-salt mine water can improve the corrosion resistance of filling materials in high-salt water.

[0116] Compared with Test Example 1 in which the immersion solution was pure water and was not prepared using high-salt mine water, the leaching ion concentration and pH value of the corrosion solution in Test Examples 2-5 were significantly lower than those in Test Example 1 after being prepared using high-salt mine water, indicating that high-salt mine water can reduce the ion leaching of filling materials in a high-salt water environment.

[0117] The above results show that the mechanical properties and long-term stability of this filling material are relatively excellent, which effectively solves the problem of reduced strength of filling paste materials subjected to corrosion by high-salt mine water in the filling mining industry, and provides a new material for the utilization of waste solid, liquid and gas in mining areas and resistance to high-salt mine water corrosion.

[0118] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for filling a collapsed zone based on the coordinated mineralization of solid, liquid and gas wastes, characterized in that: The following steps are involved: Determine the grouting filling parameters of goaf area through multi-source data fusion analysis method; Filling materials prepared with mining solid waste, mining liquid waste and gaseous waste as basic materials; The filling material is injected into the residual space of the collapsed zone in the goaf of the underground working face through the ground grouting filling system to cement the loose gangue structure in the goaf to form a filling body.

2. The method for filling the collapsed zone based on the coordinated mineralization of solid, liquid and gas wastes according to claim 1 is characterized in that: The solid waste in the mining area includes fly ash, coal gangue and slag, the liquid waste in the mining area includes high-salt mine water, and the gaseous waste includes power plant flue gas after desulfurization treatment.

3. The method for filling the collapsed zone based on the coordinated mineralization of solid, liquid and gas wastes according to claim 1 is characterized in that: The ground grouting filling system includes an aggregate storage system for storing solid waste in mining areas, an aggregate weighing and metering system for weighing solid waste in each mining area, a solid waste-based slurry preparation system for mixing liquid waste in mining areas with solid waste in mining areas, a carbon dioxide mineralization reaction system for introducing gaseous waste into the solid waste-based slurry for reaction, and a grouting system for injecting filling materials into the collapse zone.

4. A method for filling a collapsed zone based on the coordinated mineralization of solid, liquid and gas wastes according to claim 3, characterized in that: The aggregate storage system includes an ash storage tank for storing fly ash, a gangue powder tank for storing coal gangue powder, and a slag tank for storing slag; The aggregate weighing and metering system comprises a screw feeding conveyor for transporting raw materials in the aggregate storage system and a screw metering scale for weighing the weight of the raw materials transported by the screw feeding conveyor; The solid waste-based slurry preparation system includes a primary closed stirring tank for stirring various raw materials, a mine water reservoir for storing liquid waste in the mining area, and a transfer device for transferring the solid waste-based slurry after mixing and stirring; The carbon dioxide mineralization reaction system includes a secondary closed stirring tank for further stirring the raw materials and a waste gas temporary storage tank for storing gaseous waste; The grouting system comprises a grouting pump, a pressure gauge and a grouting borehole, and the grouting pump injects the filling material into the collapse zone through the grouting borehole.

5. The method for filling a collapsed zone based on the coordinated mineralization of solid, liquid and gas wastes according to claim 1 is characterized in that: The specific method for determining the grouting filling parameters of the goaf is: Based on the statistical analysis of geological exploration drilling column data, the occurrence status of the top rock layer in the mining area and the physical and mechanical characteristic parameters of different overburden layers are clarified; Use numerical simulation software to establish a geological model of the mining area, simulate the deformation, stress distribution and damage of the rock formation during mining based on the rock mechanics parameters, geological structure and other information of the mining area, analyze the simulation results, and determine the location of the key layer that plays a key role in controlling the movement and stability of the rock formation; Through laboratory tests, the conveying performance of the filling material is tested and the rheological characteristic parameters of the slurry are obtained; According to the buried depth and mining thickness of coal seams, combined with the analysis of the lithological characteristics of the roof, the final hole position of the drilling hole is determined; The calculation model of slurry diffusion radius is constructed by integrating the terminal hole layer parameters and the slurry rheological characteristic parameters; Based on the coupling analysis of the effective diffusion range of slurry and the mechanical parameters of key overburden strata, an optimization model for the spatial arrangement of boreholes along the strike and dip of the coal seam is established to determine the grouting filling parameters.

6. The method for filling a collapsed zone based on the coordinated mineralization of solid, liquid and gas wastes according to claim 1, characterized in that: The hole depth of the grouting borehole is calculated by the following formula: Where: H—depth of grouting drilling hole; H m —Deepness of coal seam; M—mining thickness; β, γ—stratum lithology adjustment coefficients; σ—mean error.

7. The method for filling a collapsed zone based on the coordinated mineralization of solid, liquid and gas wastes according to claim 1, characterized in that: The grouting pressure value range satisfies the following formula: P 孔底 ≥P≥P 地层 P 孔底 =P 孔口 +1.2Hρ1 P 地层 =Hρ Where: P—grouting filling pressure; P 孔底 —The penetration pressure of the safety isolation rock layer at the bottom of the grouting hole; P 地层 —Natural pressure of the stratum above the grouting filling layer; P 孔口 —Grouting pressure at the top of the grouting borehole; H—hole depth of the final hole layer; ρ1—specific gravity of the filling slurry; ρ—comprehensive specific gravity of the strata above the grouting filling layer.

8. The method for filling a collapsed zone based on the coordinated mineralization of solid, liquid and gas wastes according to claim 6 is characterized in that: The number of the grouting boreholes is multiple, and the spacing between two adjacent grouting boreholes along the strike direction is calculated by the following formula: W1=1.75k j R k Where: W1—hole spacing between adjacent boreholes along the strike; k j —Safety factor; R k —Slurry diffusion radius.

9. A method for filling a collapsed zone based on the coordinated mineralization of solid, liquid and gas wastes according to claim 8, characterized in that: The spacing between two adjacent grouting holes along the inclination is calculated by the following formula: Where: W2 is the distance between adjacent boreholes along the dip; h is the thickness of the key layer; E is the elastic modulus of the key layer; v is the Poisson's ratio of the key layer; L is the dip length of the goaf.

10. A collapse zone filling material based on the synergistic mineralization of solid, liquid and gas wastes, characterized in that: The invention comprises the following raw materials in parts by weight: 30-45 parts of fly ash, 10-30 parts of gangue powder, 5-10 parts of slag, 5-10 parts of alkaline additive, 15-50 parts of high-salt mine water and gaseous waste; the salt ion concentration in the high-salt water is not less than 1000 mg / L, and the alkaline additive is a mixture of sodium hydroxide and sodium silicate in a weight ratio of (30-50):(50-70).

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