A method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution

Abstract

The present invention relates to the technical field of safe mining of coal mines, and discloses a method for preventing and controlling multiple disasters in mines and sealing CO2 using a high-pressure surfactant solution, comprising the following steps: S1, weighing raw materials and mixing them evenly; clarifying the total volume of the solution and calculating the required "water-drug ratio"; S3, preparing the solution, pouring an appropriate amount of water into a high-pressure grouting pump, and then adding the mixed raw materials prepared in S1 into the water according to the "water-drug ratio" in S2, while adding an appropriate amount of acid and stirring for 2 hours; S4, drilling and grouting; S5, sealing treatment. Based on its unique chemical properties and mechanism of action, this method breaks away from the limitations of traditional technologies that rely on physical barriers or simple chemical solidification, and can cope with different complex mine environments. Compared with traditional technologies that rely solely on geological structures to seal CO2, the effect is more stable and reliable, and has stronger sustainability. This method embodies the dual benefits of green mining and economic optimization, and marks the cutting-edge progress of coal mine safety technology.

Description

Technical Field

[0001] The present invention relates to the technical field of safe coal mining, and in particular to a method for preventing and treating multiple mine disasters and sealing CO2 using a high-pressure surfactant solution. Background Art

[0002] Coal is a vital component of the energy supply, providing basic necessities like electricity and heating for daily life and ensuring the normal functioning of society. A stable coal supply is particularly crucial for meeting people's basic energy needs in areas with relatively weak energy infrastructure. Furthermore, coal mining and sales promote the rapid development of related industries, providing a significant boost to socioeconomic progress. In short, coal holds significant value in numerous social, economic, and other areas.

[0003] However, due to the unique mining environment and the impact of the "three highs and one disturbance," coal mines frequently experience dynamic hazards such as rock bursts and coal and gas outbursts. Furthermore, with the intensification of global climate change, reducing CO2 emissions has become a top priority. Research into CO2 storage in coal mines can not only reduce atmospheric greenhouse gas emissions and alleviate climate change pressures, but also achieve the comprehensive utilization and sustainable development of coal resources. Therefore, addressing these issues is of immeasurable importance for ensuring energy security, protecting the lives and health of miners, addressing climate change, and promoting the green transformation of the coal mining industry.

[0004] At present, the main solutions for controlling dynamic disasters such as rock burst and coal and gas outbursts include drilling and blasting, protective layer mining, and gas extraction. The solutions for controlling coal dust are generally spray dust removal, water injection dust removal, and foam dust removal. The effective storage of CO2 in coal mines mainly focuses on the application of filling materials. However, investigations and studies have found that the existing technologies and measures for preventing dynamic disasters can only solve a single problem in a targeted manner and cannot effectively present an integrated control solution. Coal dust control also cannot achieve a "root cause" strategy. When the coal dust content is high, water injection dust removal is often used, following a "headache, foot pain, foot" strategy. In addition, the actual completion of CO2 filling and sealing is relatively difficult, and it is impossible to control the actual storage volume and sealing effect.

[0005] In view of this, there is an urgent need for a multifunctional prevention and control method to achieve integrated management of coal mine rock burst, coal and gas outburst and other dynamic disasters, coal dust pollution, coal dust explosion and CO2 storage problems. Summary of the Invention

[0006] The present invention aims to provide a method for preventing multiple mine disasters and storing CO2 using a high-pressure surfactant solution, addressing the technical issues associated with existing methods. This method uses high-pressure fluid to fracture coal rock, increasing the permeability of the coal seam. The addition of the surfactant solution promotes the development of fissures, accelerates gas migration, enhances coal seam wettability, reduces coal dust generation, and promotes CO2 storage and adsorption. This method offers significant sustainability and economic advantages.

[0007] To achieve the above objectives, the present invention proposes a method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution, comprising the following steps:

[0008] S1. Weigh the raw materials required for the solution, such as surfactants, inorganic salts and other solids, and then place them in a blender and mix them evenly;

[0009] S2. Investigate the geological environment of the mine, determine the total volume of solution to be injected, and calculate the required "water-drug ratio";

[0010] S3. Prepare a solution according to the calculation results in S2, pour an appropriate amount of water into a high-pressure grouting pump, and then add the mixed raw materials prepared in S1 into the water according to the "water-drug ratio" in S2, add an appropriate amount of acid at the same time, and stir for 2 hours;

[0011] S4, after the stirring is completed, drilling and grouting are performed, and the mixed solution is injected into the predetermined coal seam according to the preset pressure through the grouting pump;

[0012] S5. Seal the holes to prevent solution leakage.

[0013] Preferably, the raw material surfactant in S1 is one or more of anionic surfactants (sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium dodecyl carboxylate, sodium linear alkylbenzene sulfonate, sodium α-olefin sulfonate, sodium alkyl sulfonate, succinate sulfonate, etc.) or nonionic surfactants (fatty alcohol polyoxyethylene ethers with a degree of polymerization of 9, 15, 20, etc., fatty acid polyoxyethylene esters, alkylphenol polyoxyethylene ethers, polyoxyethylene amides, polyoxyethylene fatty amines, Tween series, etc.);

[0014] Preferably, when a single surfactant is used, any of the anionic surfactants or nonionic surfactants can achieve a good wetting effect, but when the two are mixed, the ratio of anionic to nonionic is selected to be 2:1, 3:1, or 4:1, preferably 3:1;

[0015] Preferably, the raw material inorganic salt in S1 is selected from one or more of calcium chloride, sodium chloride, sodium sulfate, potassium chloride, etc.;

[0016] Preferably, the raw material ratio in S1 is determined to be 1.2%-1.5% of the mass of the inorganic salt to the mass of the surfactant;

[0017] Preferably, the mixing time of the raw materials in S1 in the stirrer is set to 1 hour to ensure uniform mixing;

[0018] Preferably, the "water-drug" ratio in S2 is determined according to the total mass of the solution. Specifically, the mass ratio of the mixed raw material to water in S1 is determined according to the critical micelle concentration of the selected surfactant.

[0019] Preferably, the acid in S3 is dilute hydrochloric acid and hydrofluoric acid, which are added to the mixed liquid in a volume ratio of 1:1, and the amount of a single acid added is 2% of the total volume of the liquid;

[0020] Preferably, the drill hole in S4 needs to be drilled to the location of the coal seam that needs to be broken and moistened;

[0021] Preferably, the grouting pressure in S4 is selected to be 85-110 MPa;

[0022] Preferably, the sealing measure in S5 can adopt a cement-based sealing material with high cost performance, and the sealing length is set to 30-50 cm;

[0023] It is worth mentioning that the reason for selecting anionic surfactants and nonionic surfactants is mainly because there are more hydrophilic groups in their molecular structure, which can wet coal dust very well. When the surfactant solution is injected into the coal seam, the hydrophobic tail chain of the surfactant molecule can form a strong hydrophobic bond with the hydrophobic groups of the coal molecular structure (because the coal molecule is a highly metamorphic substance, there are very few polar groups on its surface, so the interaction force between it and the hydrophilic group of the surfactant is relatively low), and finally form a directional adsorption form in which the hydrophilic groups are away from the coal phase and the hydrophobic groups are toward the coal phase. It can greatly enhance the wettability of coal dust, thereby reducing the possibility of coal dust flying and pollution, while cationic surfactants do not have this ability;

[0024] Preferably, the inorganic salt utilizes its unique "salt effect" in the surfactant solution to enhance the wetting ability of the surfactant solution on the coal seam;

[0025] Preferably, the acid acts to corrode the coal seam, reduce the ash content of the coal seam, promote the development of cracks, and enhance the permeability of the coal seam;

[0026] Preferably, the surfactant enhances the wettability of the coal seam, absorbs part of the free gas, adsorbs on the coal surface to occupy methane adsorption sites, converts part of the non-polarity on the coal surface into polarity, provides polar sites for CO2 adsorption, promotes CO2 to displace gas, and reduces the content of adsorbed gas;

[0027] Preferably, the role of the high-pressure liquid injection is to utilize its high pressure to destroy the coal body structure, weaken stress concentration, produce a cutting effect on the coal body, and promote the development of coal body cracks.

[0028] Compared with related technologies, the method of preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution provided by the present invention has the following beneficial effects:

[0029] 1. The high-pressure surfactant solution method for preventing multiple mine disasters and storing CO2, based on its unique chemical properties and mechanism of action, breaks away from the limitations of traditional technologies that rely on physical barriers or simple chemical solidification, and is capable of adapting to diverse and complex mine environments. The injection of high-pressure surfactant solution effectively reduces stress concentrations and significantly reduces the solution's surface tension, allowing it to more easily penetrate the fine pores and cracks in the coal seam, rapidly enhancing the wettability of the coal seam and achieving faster, more comprehensive, and more in-depth prevention and control of multiple disasters (such as rock burst, coal and gas outbursts, coal dust explosions, and pneumoconiosis). Furthermore, the solution enhances the coal seam's ability to adsorb and store CO2, promoting gas displacement. Compared to traditional technologies that rely solely on geological structures to store CO2, the solution is more stable, reliable, and sustainable.

[0030] 2. The substances in the solution are generally highly biodegradable, resulting in minimal negative environmental impact. Furthermore, by promoting the sequestration of CO2, this helps reduce greenhouse gas emissions and contributes positively to sustainable development, an advantage that is difficult to match with traditional technologies.

[0031] 3. Traditional technologies may require frequent maintenance and repairs after deployment, resulting in cumulative costs. However, the efficient penetration and stability of surfactant solutions reduce the need for subsequent maintenance and lower overall costs. Furthermore, successful CO2 storage may also generate potential carbon trading revenue, providing additional financial returns for mine operations.

[0032] 4. This method not only effectively reduces rock bursts and the risk of coal and gas outbursts, but also suppresses the spread of coal dust and reduces the possibility of explosions. Furthermore, its enhanced CO2 storage capacity helps reduce pressure within mines, further improving mine safety and protecting the lives of miners. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A diagram illustrating the specific process of the method for preventing multiple mine disasters and storing CO2 using a high-pressure surfactant solution provided by the present invention, and the mechanism of efficacy of each step;

[0034] Figure 2A schematic diagram of the molecular structure of a surfactant in the method for preventing multiple mine disasters and storing CO2 using a high-pressure surfactant solution provided by the present invention;

[0035] Figure 3 A diagram showing the effect of high-pressure water flow entering a coal body in the method for preventing multiple mine disasters and storing CO2 provided by the present invention;

[0036] Figure 4 A diagram showing the mechanism of the conversion of coal from non-polar to polar in the method for preventing multiple mine disasters and storing CO2 using a high-pressure surfactant solution provided by the present invention;

[0037] Figure 5 Schematic diagram of the mechanism of CO2 effectively displacing gas in the method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution provided by the present invention.

[0038] Figure numerals: 1. surfactant; 2. hydrophilic group; 3. hydrophobic tail chain; 4. coal phase; 5. high-pressure fluid; 6. crack; 7. inorganic salt; 8. acid; 9. hydrophobic interface; 10. hydrophilic interface; 11. gas; 12. CO2. DETAILED DESCRIPTION

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example 1

[0040] Please refer to Figure 1-5 The present invention proposes a method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution, comprising the following steps:

[0041] S1. Weigh the raw materials required for the solution, such as surfactant 1, inorganic salt 7 and other solids, according to the established method, and then place them in a blender and mix them evenly;

[0042] S2. Investigate the geological environment of the mine, determine the total volume of high-pressure fluid to be injected, and calculate the required "water-drug" ratio;

[0043] S3. Prepare a solution according to the calculation results in S2, pour an appropriate amount of water into a high-pressure grouting pump, and then add the mixed raw materials prepared in S1 into the water according to the "water-drug" ratio in S2, and add an appropriate amount of acid 8 at the same time, and stir for 2 hours;

[0044] S4, after the mixing is completed, drilling and grouting are performed, and the high-pressure fluid 5 is injected into the predetermined coal seam 4 according to the preset pressure through the grouting pump;

[0045] S5. Seal the holes to prevent solution leakage.

[0046] In a further embodiment of the present invention, the raw material surfactant 1 in S1 is one or more of anionic surfactants (sodium dodecyl sulfonate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium tetradecyl sulfate, sodium dodecylcarboxylate, sodium linear alkylbenzenesulfonate, sodium α-olefinsulfonate, sodium alkylsulfonate, succinate sulfonate, etc.) or nonionic surfactants (fatty alcohol polyoxyethylene ethers with a degree of polymerization of 9, 15, 20, etc., fatty acid polyoxyethylene esters, alkylphenol polyoxyethylene ethers, polyoxyethylene amides, polyoxyethylene fatty amines, Tween series, etc.);

[0047] In a further embodiment of the present invention, when a single surfactant 1 is used, either the anionic surfactant 1 or the nonionic surfactant 1 can achieve a good wetting effect, but when the two are mixed, the ratio of anionic: nonionic = 2:1, 3:1, 4:1 is selected, preferably 3:1;

[0048] In a further embodiment of the present invention, the raw material inorganic salt 7 in S1 is selected from one or more of calcium chloride, sodium chloride, sodium sulfate, potassium chloride, etc.;

[0049] In a further embodiment of the present invention, the ratio of the raw materials in S1 is determined to be 1.2%-1.5% by mass of the inorganic salt 7 to the mass of the surfactant 1;

[0050] In a further embodiment of the present invention, the mixing time of the raw materials in S1 in the stirrer is set to 1 h to ensure uniform stirring;

[0051] In a further embodiment of the present invention, the "water-drug" ratio in S2 is determined according to the total mass of the solution. Specifically, the mass ratio of the mixed raw material and water in S1 is determined according to the critical micelle concentration of the selected surfactant;

[0052] In a further embodiment of the present invention, the acid 8 in S3 is diluted hydrochloric acid and hydrofluoric acid, which are added to the mixed liquid in a volume ratio of 1:1, and the amount of a single acid added is 2% of the total volume of the liquid;

[0053] It is worth mentioning that the reason for selecting anionic surfactant 1 and nonionic surfactant 1 is mainly because there are more hydrophilic groups 2 in their molecular structure, which can wet coal dust well. When the surfactant 1 solution is injected into the coal seam 4, the hydrophobic tail chain 3 of the surfactant 1 molecule can form a strong hydrophobic bond with the hydrophobic group of the coal molecular structure (because the coal molecule is a highly metamorphic substance, there are very few polar groups 2 on its surface, so the interaction force between it and the hydrophilic group 2 of the surfactant is relatively low), eventually forming a directional adsorption form in which the hydrophilic group 2 is away from the coal phase 4 and the hydrophobic group 3 is toward the coal phase 4. This can greatly enhance the wettability of coal dust, thereby reducing the possibility of coal dust being lifted and polluting. Cationic surfactants do not have this ability.

[0054] In a further embodiment of the present invention, the inorganic salt 7 utilizes its unique "salt effect" in the surfactant 1 solution to enhance the wetting ability of the surfactant 1 solution on the coal seam 4;

[0055] In a further embodiment of the present invention, the acid 8 functions to corrode the coal seam 4, promote the development of cracks, and enhance the permeability of the coal seam 4;

[0056] In a further embodiment of the present invention, the surfactant 1 functions to enhance the wettability of the coal seam 4, absorb part of the free gas 11, adsorb it on the coal surface to occupy methane adsorption sites, convert part of the non-polar interface 9 on the coal surface into a polar interface 10, provide polar sites for the adsorption of CO2 12, promote the displacement of gas by CO2 12, and reduce the content of adsorbed gas;

[0057] In a further embodiment of the present invention, the role of the injection of the high-pressure fluid 5 is to utilize its high pressure to destroy the structure of the coal seam 4, weaken stress concentration, produce a cutting effect on the coal body, and promote the development of coal body cracks 6;

[0058] The present invention proposes a method for preventing multiple mine disasters and storing CO2 using a high-pressure surfactant solution. The main principle is:

[0059] (1) Relying on high-pressure fluid 5 to generate strong pressure on the coal seam 4 in the mine, thereby creating cracks 6, in other words, "hydraulic fracturing or hydraulic fracturing". The cracks 6 generated can greatly change the stress concentration of the coal seam 4, transfer the ground stress, and reduce the possibility of rock burst;

[0060] (2) The generated fissures 6 can enhance the permeability of the coal seam 4. At the same time, the addition of dilute hydrochloric acid and hydrofluoric acid 8 can corrode and weaken the coal seam 4, further promoting the development of fissures 6. The high-pressure fluid 5 and the acid 8 complement each other, thereby enhancing stress transfer and increasing the possibility of gas 11 migration, providing a channel for gas 11 migration, and reducing the risk of rock burst and coal and gas outbursts;

[0061] (3) Surfactant 1 can use its special structural form to absorb and digest part of the gas 11, reducing the probability of coal and gas outburst, and the hydrophobic tail chain 3 of the surfactant 1 molecule can form a strong hydrophobic bond with the hydrophobic group of the coal molecular structure (because the coal molecule is a highly metamorphic substance, there are very few polar groups on its surface, so the interaction force between it and the hydrophilic group 2 of the surfactant is relatively low), and finally form a directional adsorption form in which the hydrophilic group 2 is away from the coal phase 4 and the hydrophobic group 3 is toward the coal phase 4, so that the coal is transformed from the hydrophobic interface 9 to the hydrophilic interface 10, which greatly enhances the wettability of the coal dust, thereby reducing the possibility of coal dust flying and pollution, and reducing the chance of coal dust explosion and workers suffering from pneumoconiosis;

[0062] (4) The surfactant 1 is directionally adsorbed on the coal surface, occupying the adsorption sites of the adsorbed gas 11. When CO212 is introduced to displace the gas 11, the surfactant's higher adsorption capacity for CO212 than for gas 11 can be utilized to cause competitive adsorption between the two. Ultimately, a sustainable development situation is shown in which the adsorption amount of CO212 increases while the adsorption amount of gas 11 decreases, which promotes the storage of CO212 and the extraction of gas, reduces the possibility of coal and gas outbursts, and can play a role in storing CO2, thereby promoting the sustainable development of energy.

[0063] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any modification or equivalent replacement using the technical solution of the present invention, or direct or indirect application in other related technical fields, shall be included in the patent protection scope of the present invention.

Claims

1. A method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution, characterized in that: The steps include: S1. Weigh the raw materials required for the solution, such as surfactant (1) and inorganic salt (7) solids, according to the established method, and then place them in a blender and mix them evenly; S2. Investigate the geological environment of the mine, determine the total volume of high-pressure fluid (5) to be injected, and calculate the required "water-drug ratio"; S3. Prepare a solution according to the calculation result in S2, pour an appropriate amount of water into the high-pressure grouting pump, and then add the mixed raw materials prepared in step S1 into the water according to the "water-drug" ratio in S2, and add an appropriate amount of acid (8) at the same time, and stir for 2 hours; S4, after the mixing is completed, drilling and grouting are performed, and the high-pressure fluid (5) is injected into the predetermined coal seam (4) according to the preset pressure through the grouting pump; S5, sealing treatment to prevent solution leakage; The raw material surfactant (1) in S1 is an anionic surfactant or a nonionic surfactant, the anionic surfactant is one or more of sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium dodecyl carboxylate, sodium linear alkylbenzene sulfonate, sodium α-olefin sulfonate, sodium alkyl sulfonate, and succinate sulfonate, and the nonionic surfactant is one or more of fatty alcohol polyoxyethylene ethers with a degree of polymerization of 9, 15, 20, etc., fatty acid polyoxyethylene esters, alkylphenol polyoxyethylene ethers, polyoxyethylene amides, polyoxyethylene fatty amines, and Tween series; when a single surfactant (1) is used, the anionic surfactant (1) or the nonionic surfactant (1) can both achieve a good wetting effect, but when the two are mixed, the ratio of anionic to nonionic is selected to be 2:1, 3:1, or 4:

1.

2. The method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution according to claim 1, characterized in that: The raw material inorganic salt (7) in step S1 is selected from one or more of calcium chloride, sodium chloride, sodium sulfate, and potassium chloride.

3. The method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution according to claim 1, wherein: The raw material ratio in step S1 is determined to be 1.2%-1.5% of the mass of the inorganic salt (7) to the mass of the surfactant (1).

4. The method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution according to claim 1, wherein: The acid (8) in step S3 is diluted hydrochloric acid and hydrofluoric acid, which are added to the mixed liquid in a volume ratio of 1:1, and the amount of a single acid added is 1.5-2% of the total volume of the liquid.

5. The method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution as claimed in claim 1, characterized in that: The selected anionic surfactant (1) and nonionic surfactant (1) have a large number of hydrophilic groups (2) in their molecular structures, which can wet the coal dust well. When the surfactant (1) solution is injected into the coal seam (4), the hydrophobic tail chain (3) of the surfactant (1) molecule can form a strong hydrophobic bond with the hydrophobic group of the coal molecular structure (because the coal molecule is a highly metamorphic substance, there are very few polar groups (2) on its surface, so the interaction force between it and the hydrophilic group (2) of the surfactant is relatively low), and finally a directional adsorption form is formed in which the hydrophilic group (2) is away from the coal phase and the hydrophobic group (3) is toward the coal phase, which can well enhance the wettability of the coal dust, thereby reducing the possibility of coal dust being blown up and polluting.

6. The method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution according to claim 1, wherein: The inorganic salt (7) can utilize its unique "salt effect" in the surfactant (1) solution to enhance the wetting ability of the surfactant (1) solution on the coal seam (4).

7. The method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution according to claim 1, wherein: The acid (8) can corrode the coal seam (4), promote the development of cracks, and enhance the permeability of the coal seam (4).

8. The method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution according to claim 1, wherein: The surfactant (1) can enhance the wettability of the coal seam (4), absorb part of the free gas (11), adsorb on the coal surface to occupy the methane adsorption site, convert part of the non-polar interface (9) on the coal surface into a polar interface (10), provide polar sites for the adsorption of CO2 (12), promote CO2 (12) to displace gas, and weaken the content of adsorbed gas.

9. The method for preventing and controlling multiple mine disasters and storing CO2 using a high-pressure surfactant solution according to claim 1, wherein: The injection of the high-pressure fluid (5) can utilize its high pressure to destroy the structure of the coal seam (4), weaken stress concentration, produce a cutting effect on the coal body, and promote the development of coal body cracks (6).

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