Environment-friendly oxygen-isolating fire preventing and extinguishing material based on CCS as well as preparation method and application thereof

Abstract

The invention relates to the technical field of coal mine fire prevention and control, and discloses a CCS-based environment-friendly oxygen-isolating fire preventing and extinguishing material and a preparation method and application thereof.The CCS-based environment-friendly oxygen-isolating fire preventing and extinguishing material comprises a water-permeable wear-resistant cover, a solid waste-based self-foaming carbon capture material, a waterproof sealing compound fabric and a net-shaped support, the net-shaped support serves as a supporting frame to be evenly distributed and connected between the water-permeable wear-resistant cover and the waterproof sealing composite fabric, and the structure of the net-shaped support is filled with the solid waste-based self-foaming carbon capture material. According to the method, integrated innovation of multiple technologies of efficient utilization of solid waste, improvement of material performance, prevention and control of goaf disasters and mineralization and storage of CO2 is embodied, air leakage can be effectively reduced through application of the oxygen insulation material and geological storage of CO2, and prevention and control of goaf coal spontaneous ignition are achieved; the efficient application of the solid waste material and the mineralization and storage of CO2 can provide a new thought and direction for solving the problems of global climate change and resource shortage in the coal mine field.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mine fire prevention and control, and particularly relates to an environmentally friendly oxygen isolation and fire prevention material based on CCS, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous growth of the global dependence on coal resources, the mining and utilization of coal mines are facing increasingly severe environmental challenges, especially the problems of goafs and surface fissures generated during the mining of shallow-buried coal seam groups. The mining of shallow-buried coal seam groups often causes surface cracks and goafs. These cracks not only affect the stability of the surface, but also may cause external air to infiltrate into the goaf, thereby triggering safety hazards such as coal seam spontaneous combustion and fires. In addition, there is also a risk of leakage of CO2 in the goaf. On the one hand, this will have an impact on the surrounding environment, and on the other hand, it may also pose a threat to the safe production of coal mines. In this context, it is particularly important to develop an efficient oxygen isolation and fire prevention material.

[0003] In recent years, oxygen isolation and fire prevention materials based on solid waste utilization have gradually received attention. Such materials not only have good oxygen isolation performance, but also can effectively block surface fissures, prevent external air from entering the goaf, and reduce the risk of spontaneous combustion. At the same time, these materials have good environmental adaptability and economy, meeting the requirements of sustainable development. More importantly, if this kind of oxygen isolation and fire prevention material can be combined with CCS (carbon dioxide capture and storage) technology to react with CO2 in the goaf to form stable compounds, thereby while blocking the infiltration of oxygen, effectively absorbing and storing the CO2 escaping from the goaf. This characteristic not only helps to relieve the pressure brought by climate change, but also helps to improve the safety of coal mines. By combining solid waste-based oxygen isolation and fire prevention materials with CCS technology, a new type of coal mine oxygen isolation and fire prevention technology is formed, which can not only block fissures and isolate oxygen, but also realize the capture and utilization of CO2, achieving the dual effects of environmental protection and resource utilization.

[0004] At present, coal mine oxygen isolation and fire prevention technologies mainly use traditional oxygen isolation materials such as swelling agents and flame retardants, but these materials have some defects, such as poor oxygen isolation effect, easy aging, and difficult to be applied to complex geological conditions. At the same time, traditional oxygen isolation materials usually cannot effectively absorb CO2, resulting in the problem of CO2 leakage in the goaf being difficult to solve. In addition, the goafs of shallow-buried coal seam groups often have a large air leakage volume, which will cause rapid leakage of CO2, thereby increasing the safety risk of coal mines. Therefore, developing an oxygen isolation material that can effectively plug leaks and absorb CO2 is of great significance for improving the safety production level of coal mines and reducing environmental pollution. Summary of the Invention

[0005] In view of the problems existing in the above-mentioned prior art, the object of the present invention is to provide an environmentally friendly oxygen isolation and fire prevention material based on CCS (carbon dioxide capture and storage), as well as its preparation and application. By combining the fire prevention technology with environmentally friendly oxygen isolation materials and CCS technology, an innovative solution is provided for solving the problems of surface fissure sealing in shallow buried coal seams, air leakage in goafs, and CO2 storage. The implementation of this technology will help improve the safety of coal mines, reduce environmental pollution, and promote the sustainable development of the coal industry.

[0006] To achieve the above object, on the one hand, the present invention provides a preparation method of an environmentally friendly oxygen isolation and fire prevention material based on CCS, including the following steps:

[0007] Step 1), material prefabrication;

[0008] ⑤ Prefabricate a water-permeable and wear-resistant cover

[0009] Blend spandex, polyester fiber, and polypropylene fiber to form a fabric, then coat the surface of the fabric with polyurethane, cure it, and obtain a water-permeable and wear-resistant cover;

[0010] ⑥ Prefabricate a waterproof and sealed composite fabric

[0011] Soak glass fibers with a diameter of 9 - 13μm and aramid fibers with a diameter of 12 - 15μm respectively in a solution of polyurethane glue, then take them out and dry and cure; lay the treated glass fibers and aramid fibers on both sides of a Sympatex film with a thickness of 10 - 20μm, and then perform hot pressing treatment to obtain a waterproof and sealed composite fabric with a three-layer structure;

[0012] ⑦ Prefabricate a solid waste-based self-foaming carbon capture material

[0013] Mix steel slag, slag, fly ash, desulfurized gypsum, modified starch-based foaming agent, coconut oil amide, xanthan gum, and water evenly to obtain a solid waste-based self-foaming carbon capture material, where the modified starch-based foaming agent is obtained by compounding corn starch and sodium silicate;

[0014] ⑧ Prefabricate a mesh support

[0015] Cut loofah into segments with a size of 1 - 5 cm, and soak it in a mixed aqueous solution of chloroprene emulsion and VAE emulsion to modify the loofah, obtaining modified loofah fibers; then control the temperature of the hot press to 100 - 150°C and apply a pressure of 1 - 5 MPa for hot pressing treatment to melt-bond thermoplastic polyurethane materials with modified loofah fibers and polypropylene / polyester fibers to form a multi-layer structure and obtain a mesh support.

[0016] Step 2), composite assembly of prefabricated materials;

[0017] First, lay the waterproof and sealed composite fabric as the bottom surface, arrange the mesh supports evenly spaced on the waterproof and sealed composite fabric and fix them with an adhesive; then fill the waste-based self-foaming carbon capture material within the framework formed by the mesh supports to uniformly fill the entire space of the mesh supports; finally, lay the permeable and wear-resistant cover as the top surface and fix it with the mesh supports through an adhesive to obtain the CCS-based environmentally friendly oxygen isolation and fire prevention material.

[0018] As a further preferred technical solution of the present invention, in the raw materials of the permeable and wear-resistant cover: textile waste spandex accounts for 10-15 wt%, polyester fiber accounts for 40-55 wt%, and polypropylene fiber accounts for 30-50 wt%; the coating amount of polyurethane accounts for 10-14% of the total mass of the fibers. Specifically, spandex is blended with polyester fiber and polypropylene fiber in a certain proportion, and polyurethane is uniformly coated on the fabric by means of roller coating. Then, the coated material is naturally cured at room temperature for 24 h to preliminarily cure the polyurethane coating. Then, the cured material is placed in an oven and dried at 60-80 °C for 2-4 h to ensure complete curing of the coating.

[0019] As a further preferred technical solution of the present invention, in the fiber raw materials used for the waterproof and sealed composite fabric, the mass ratio of aramid fiber is 45-55%, and the mass ratio of glass fiber is 55%-45%.

[0020] As a further preferred technical solution of the present invention, after glass fiber and aramid fiber are respectively soaked and treated in a solution of polyurethane glue, the fibers are taken out and cured. Preferably, the polyurethane glue is cured by natural drying for 24 h to ensure sufficient penetration. Then, the treated glass fiber, Sympatex film, and treated aramid fiber are stacked in sequence, and then hot pressing treatment is carried out. The hot pressing treatment process is preferably: hot pressing at 120-150 °C and a pressure of 10-15 MPa for 5-10 minutes through a hot pressing device to effectively bond between layers and form an integral waterproof and sealed composite fabric.

[0021] As a further preferred technical solution of the present invention, the raw material components of the waste-based self-foaming carbon capture material are prepared according to the following weights: 30-40 parts of steel slag, 25-35 parts of slag, 15-25 parts of fly ash, 5-10 parts of desulfurized gypsum; the mass of the modified starch-based foaming agent and coconut oil amide accounts for 3%-5% of the total mass of the waste-based self-foaming carbon capture material; the mass ratio of the modified starch-based foaming agent to coconut oil amide is 4:1, and the modified starch-based foaming agent is prepared from corn starch and water glass according to a mass ratio of 1:0.3; the dosage of xanthan gum is 0.1%-0.3% of the total mass of the modified starch-based foaming agent and coconut oil amide; the water-solid ratio is 0.4-0.5.

[0022] As a further preferred technical solution of the present invention, the mesh support is composed of modified loofah fiber accounting for 35 - 45% by mass, 55 - 65% of polypropylene / polyester fiber, and is melt - bonded by adding 15% of thermoplastic polyurethane.

[0023] According to another aspect of the present invention, the present invention also provides an environmentally friendly oxygen - isolating and fire - preventing material based on CCS, which is prepared by the above - mentioned method.

[0024] According to still another aspect of the present invention, the present invention also provides an application of an environmentally friendly oxygen - isolating and fire - preventing material based on CCS in preventing and controlling coal spontaneous combustion in the gob area of shallow - buried coal seams, including: unfolding the environmentally friendly oxygen - isolating and fire - preventing material and completely covering the surface fissures of the shallow - buried coal seam; then injecting water into the environmentally friendly oxygen - isolating and fire - preventing material so that the waste - based self - foaming carbon capture material naturally foams and solidifies inside the structure of the mesh support.

[0025] The method for applying the environmentally friendly oxygen - isolating and fire - preventing material based on CCS to a coal mine for oxygen - isolation and fire - prevention is as follows:

[0026] S1: On - site assessment and investigation

[0027] Before sealing the surface fissures of the shallow - buried coal seam and CO2 sequestration, evaluate the environmental impact of the air - leakage area to ensure that it will not cause negative impacts on the surrounding ecosystem. Then conduct a detailed investigation and assessment of the corresponding gob area and surface fissures to determine the depth, width and distribution of the fissures, providing a basis for the subsequent filling plan. According to the investigation results, determine the specific locations where oxygen - isolating materials need to be filled.

[0028] S2: Preparation of the environmentally friendly oxygen - isolating and fire - preventing material based on CCS and treatment of the on - site surface.

[0029] According to the size and coverage area of the on - site fissures, confirm the specifications of the oxygen - isolating material, prepare the necessary construction tools. Before laying the oxygen - isolating material, check the surface humidity. If it is too wet, wait for the surface to dry naturally. At the same time, before implementing surface crack sealing in the air - leakage area of the surface fissures of the shallow - buried coal seam after investigation, clean and treat the surface around the sealing area to ensure good adhesion of the environmentally friendly oxygen - isolating material. After cleaning, it is necessary to ensure that the surface is dry and free of impurities. Use concrete filling materials to seal larger or obvious fissures to enhance the bonding effect of the oxygen - isolating material.

[0030] S3: Laying and fixing of the environmentally friendly oxygen - isolating and fire - preventing material based on CCS

[0031] According to the results of preliminary investigation and assessment, lay the environmentally friendly oxygen isolation material flat in the designated area, ensure that the coverage area is sufficient, and closely combine it with the surrounding soil. Use mechanical fixing devices (such as nails, screws, etc.) to fix it to the ground to prevent its displacement. Then, inject water into the oxygen isolation material several times to enable the waste-based self-foaming carbon capture material to naturally foam and cure inside the on-line pile structure. The water injection interval is maintained at 3 h / time, and the number of water injection times is 8 - 10 times. For larger fissures, overlapping laying can be carried out if necessary to ensure that the material can form a complete oxygen isolation barrier to prevent the penetration of oxygen.

[0032] S4: Injection and Sequestration of CO2

[0033] Transport the CO2 captured by the coal-fired power plant in the factory and mining area to the goaf area below the plugged surface fissure through drilling or pipelines. The sealed goaf and the surface can form a closed space to sequester CO2. At the same time, the oxygen isolation material can also absorb and hinder the CO2 escaping from the goaf to the air leakage channel, thereby achieving multiple effects such as synergistic reduction of pollution and carbon emissions and inerting the spontaneous combustion environment of coal in the goaf.

[0034] S5: Establishment of Monitoring System

[0035] Real-time monitor parameters such as the oxygen concentration, temperature, and pressure in the goaf in the technical implementation area through sensors to ensure the effectiveness of the oxygen isolation barrier. Regularly inspect the filled environmentally friendly oxygen isolation material to evaluate its structural integrity and oxygen isolation effect. If defects are found, promptly supplement or maintain the material. If too high a temperature or oxygen concentration is found in the goaf, to ensure safety, the emergency response procedure should be quickly activated, and the rapid reaction ability of the oxygen isolation material should be used to carry out local isolation again to slow down the rate of coal oxidation and temperature rise.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. The raw materials of the CCS-based environment-friendly oxygen isolation and fire prevention material of the present invention are reasonably selected. Among them, spandex, polyester fiber, polypropylene fiber, and polyurethane with a high solid content are selected to form a water-permeable and wear-resistant cover. The introduction of polyurethane greatly enhances the anti-permeability and flexibility of the plugging material. The material is composed of a mixture of polyester fiber and glass fiber, and then treated with Sympatex film to obtain a waterproof and sealed composite fabric. After being treated with Sympatex film, the waterproof performance of the area where the waterproof and sealed composite fabric contacts the gob is significantly improved. Traditional plugging materials mainly rely on cement and inorganic materials, which have low flexibility and toughness, are prone to deterioration in a humid environment, and have poor tensile strength. However, this material combines a variety of high-performance fibers, enhancing its stability in harsh environments and reducing the frequency of material failures and maintenance. The waterproof and sealed composite fabric ensures good waterproof performance, forming an effective protection system. The elasticity and toughness of the material enable it to adapt to minor changes on the ground surface, maintain good sealing performance, and contribute to improving the safety and reliability of the overall project. The mesh frame connecting the water-permeable and wear-resistant cover and the waterproof and sealed composite fabric is prepared by compounding polypropylene fiber or polyester fiber and modified loofah sponge. This line pile will generate good toughness and elasticity between the cementitious materials, providing support and structural stability for the solid waste-based self-foaming carbon capture material filled in the middle, while enhancing the overall strength and durability of the material.

[0038] 2. In the CCS-based environment-friendly oxygen isolation and fire prevention material of the present invention, the connection of the two layers of fabrics of the oxygen isolation material and the role of the intermediate filling material form an overall plugging system with high toughness, waterproof sealing, and structural stability. The overall frame structure has a certain deformability, forming a multi-layer protection barrier that can carry the solid waste-based self-foaming carbon capture material. This design can effectively disperse the pressure, reduce local stress concentration, form a good airtight environment, and further improve the oxygen isolation and fire prevention effect. In addition, the line pile frame provides structural support, enabling the upper and lower fabrics to maintain a certain distance, thus forming a stable air layer to enhance the oxygen isolation effect. At the same time, this frame can also promote the uniform distribution of the intermediate self-foaming carbon capture material, ensuring its good contact with the two layers of fabrics and improving the carbon capture efficiency.

[0039] 3. In the environmentally friendly oxygen isolation and fire prevention material based on CCS of the present invention, the solid waste-based self-foaming carbon capture material preferably uses four solid wastes, namely steel slag, slag, fly ash, and desulfurized gypsum, as the base materials, and combines a variety of clinker-modified starch-based foaming agents and additives to design a composite material integrating functions such as comprehensive utilization of solid waste, CO2 capture and mineralization and storage, and oxygen isolation and fire prevention of foamed cementitious materials. First of all, the selection of the four solid wastes reflects the compositional complementarity, mutual promotion of hydration reactions, strength characteristics, impermeability and durability, environmental friendliness and sustainability during the hydration process. These characteristics are specifically manifested as follows: steel slag has high alkalinity and activity, can react with water to generate hydrated silicate and hydrated aluminate, and provide early strength; slag can react slowly in water to provide long-term strength and durability. When the two are combined, they can provide rich silicates, which helps to form a hydraulic cementitious material, and the early strength and late strength can be synergistically improved. As an active mineral admixture, fly ash can react with calcium-based oxides in steel slag and slag to form calcium silicate hydrate (C-S-H), further improving the strength and durability of the hardened body. In addition, during the hydration reaction, desulfurized gypsum can also play a role in adjusting the pH value and improving the effectiveness of the reaction. The gypsum hydrate formed by it and the C-S-H gel grow and interpenetrate with each other to form a dense network structure. At the same time, the solid waste-based material contains a large amount of alkaline components such as calcium and magnesium, which can chemically react with CO2 to convert CO2 into stable carbonate minerals. At the same time, the self-foaming process increases the specific surface area and porosity of the oxygen isolation material, providing more reaction interfaces for the contact between CO2 and alkaline components. Therefore, the raw materials in the self-foaming carbon capture material described in the present invention can simultaneously produce excellent effects on sealing the air leakage in the gob area of shallowly buried coal seams and storing CO2.

[0040] 4. In the application of the CCS-based environment-friendly oxygen isolation and fire prevention material of the present invention, through multiple water injection processes, the synergistic hydration reaction of the four solid wastes can not only release heat, accelerate the curing of the material, but also generate cementitious materials such as calcium silicate hydrate, enhancing the strength and stability of the final product. On this basis, the combination of the solid waste with the modified starch-based foaming agent and coconut oil amide not only enhances the self-foaming performance of the material, forming a number of pore structures. Such a structure can not only improve the flexibility and deformation resistance of the material, helping to adapt to the continuous changes in the geological morphology of shallowly buried coal seams, but also due to the porous structure of the material, a large amount of CO2 can be captured inside the material and gradually mineralized, enhancing the continuous capture ability of the material. At the same time, the reaction mechanism between the modified starch and coconut oil amide does not involve CO2 released by acid-base reactions or thermal reactions, so CO2 is not generated during the foam formation process, which ensures the environmental friendliness of the foaming agent. In addition, multiple water injections can increase the contact opportunity between CO2 and the solid waste material, enhancing the mineralization efficiency of CO2. As the hydration process progresses, CO2 is gradually captured and converted into mineralized substances. The gradual progress of this conversion process helps to improve the stability of the mineralization reaction and contributes to the long-term sequestration of the CO2 leaking from the goaf.

[0041] 5. In the application of the CCS-based environment-friendly oxygen isolation and fire prevention material of the present invention, under the combined action of the self-foaming carbon capture material, two layers of fabric materials and the intermediate mesh frame, a lightweight and porous integrated oxygen isolation, fire prevention and collaborative carbon emission reduction technology is formed, which not only reduces the density of the material, but also improves its heat insulation and oxygen isolation performance, enhancing the fire prevention effect. On the one hand, the oxygen isolation material is used to block the air leakage fissures, control the flow of oxygen between the goaf and the surface fissures, form an oxygen isolation barrier, and prevent the penetration of external oxygen; on the other hand, during the mining process, a closed underground space is formed by blocking the fissures, and the CO2 captured by the coal-fired power plant in the mining area is introduced into the underground space blocked by the oxygen isolation material through a pipeline or a borehole, forming geological sequestration of CO2. At the same time, the CO2 escaping upward from the goaf is converted into solid mineralized substances (such as calcium carbonate) by the solid waste-based self-foaming carbon capture material in the environment-friendly oxygen isolation material, further enhancing the strength and sealing performance of the oxygen isolation material. The coal mine oxygen isolation and fire prevention technology combining the environment-friendly oxygen isolation material and CCS can effectively reduce the fire risk in the coal mine and improve the safety of the mine. At the same time, the development and application of the solid waste-based material realizes the recycling of resources, conforms to the concept of sustainable development, and combined with CCS technology, can accelerate the mineralization and sequestration of CO2 in the coal mine area, reduce greenhouse gas emissions, and has positive significance for environmental protection.

[0042] 6. The CCS-based environment-friendly oxygen isolation and fire prevention material of the present invention can be applied to different types of coal mines, especially for the surface fissure air leakage in shallow buried coal seam groups. It can effectively reduce potential safety hazards according to its special mining conditions. From the perspective of solid waste utilization, this technology is based on all-solid waste materials such as steel slag, slag, fly ash, and desulfurized gypsum. It not only realizes the recycling of waste but also reduces the demand for new materials, thus reducing resource consumption and environmental pollution. From the perspective of carbon emission reduction, on the one hand, the self-foaming carbon capture material prepared in the oxygen isolation material can absorb CO2 generated by spontaneous combustion in the goaf. On the other hand, by injecting CO2 into the sealed space formed by blocking the surface fissure air leakage and the goaf with the oxygen isolation material for long-term carbon reduction, a continuous low-oxygen environment is formed, improving the safety and stability of the mine and reducing the risks of fire and explosion. Generally speaking, this fire prevention technology integrates the organic combination of multiple technologies such as oxygen isolation, fire prevention, carbon reduction, and solid waste utilization, forming a complete set of system solutions, realizing the maximum utilization of resources, promoting the integrated utilization of solid waste and CO2, and having higher comprehensive application value compared with existing technologies.

[0043] 7. The preparation and application method of the CCS-based environment-friendly oxygen isolation and fire prevention material of the present invention reflects the integrated innovation of multiple technologies, including the efficient utilization of solid waste, the improvement of material properties, the prevention and control of goaf disasters, and the mineralization and storage of CO2. The application of the oxygen isolation material and the geological storage of CO2 can effectively reduce air leakage and achieve the prevention and control of spontaneous combustion of coal in the goaf. In addition, the efficient application of solid waste materials and the mineralization and storage of CO2 can provide new ideas and directions for the coal mining field to solve global climate change and resource shortage problems.

[0044] 8. The preparation and application method of the CCS-based environment-friendly oxygen isolation and fire prevention material of the present invention can better adapt to complex terrains and fissure morphologies during the process of oxygen isolation for shallow buried coal seam groups' surface fissures. It is simple to operate, with clear steps, and can effectively isolate oxygen, prevent coal mine fires, and achieve the capture and mineralization and storage of CO2. The implementation and application of this technology not only reduce the potential hazards of coal mine fires but also promote the recycling of solid waste, reflecting the environmental protection and sustainable development concepts of modern mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0046] Figure 1 It is a schematic structural diagram of the solid waste-based high-toughness material of the present invention.

[0047] Figure 2 It is a schematic structural diagram of the application of the solid waste-based high-toughness material of the present invention for oxygen isolation in the surface fissures of shallow buried coal seams.

[0048] In the figure: 1. Permeable and wear-resistant cover, 2. Waterproof and sealed composite fabric, 3. Solid waste-based self-foaming carbon capture material, 4. Mesh support, 100. Solid waste-based high-toughness material.

[0049] The realization of the object, functional features, and advantages of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Specific embodiments

[0050] The following further details the specific embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention and are not intended to limit the present invention.

[0051] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The test reagents used in the following embodiments are all conventional biochemical reagents unless otherwise specified; the experimental methods are all conventional methods unless otherwise specified.

[0052] Embodiment 1:

[0053] As Figure 1 shown, an environmentally friendly oxygen-isolating and fire-extinguishing material based on CCS (carbon dioxide capture and storage) includes a permeable and wear-resistant cover 1, a solid waste-based self-foaming carbon capture material 3, a waterproof and sealed composite fabric 2, and a mesh support 4. The permeable and wear-resistant cover 1 and the waterproof and sealed composite fabric 2 are laid flat relative to each other up and down. The mesh support 4 has a three-dimensional mesh structure and is uniformly arranged and connected as a support frame between the permeable and wear-resistant cover 1 and the waterproof and sealed composite fabric 2. The solid waste-based self-foaming carbon capture material 3 is filled in the structure of the mesh support 4 between the permeable and wear-resistant cover 1 and the waterproof and sealed composite fabric 2, thereby forming a three-layer composite structure.

[0054] The permeable and wear-resistant cover, the solid waste-based self-foaming carbon capture material, the waterproof and sealed composite fabric, and the mesh support are prefabricated by the following methods respectively:

[0055] The permeable and wear-resistant cover is formed by blending 10% wt spandex, 40% wt polyester fiber, and 55% wt polypropylene fiber to form a fabric, and then coating a polyester coating accounting for 15% of the total fiber mass on the fabric. The specific preparation method is as follows: Blend spandex with polyester fiber and polypropylene fiber in proportion, and then evenly coat the polyurethane coating on the fabric by roll coating. The coated material is naturally cured at room temperature for 24 h to preliminarily cure the polyurethane coating. The cured material is placed in an oven and dried at 80 °C for 2 h to ensure complete curing of the coating, and the permeable and wear-resistant cover is obtained for standby.

[0056] The solid waste-based self-foaming carbon capture material is composed of 40 parts of steel slag, 30 parts of slag, 20 parts of fly ash, and 10 parts of desulfurized gypsum. According to a water-solid ratio of 0.5, a modified starch-based foaming agent and coconut oil amide (the mass ratio of the modified starch-based foaming agent to coconut oil amide is 4:1) accounting for 4% of the total mass of the powder (ash) body are added, and xanthan gum accounting for 0.2% of the total amount of the modified starch-based foaming agent and coconut oil amide is mixed. Among them, the modified starch-based foaming agent is mainly prepared by compounding corn starch and sodium silicate according to a mass ratio of 1:0.3. First, the corn starch is dissolved in water, and then sodium silicate is added and mixed thoroughly to obtain it.

[0057] The waterproof and sealing composite fabric is made of 45% aramid fiber and 55% glass fiber, and is treated with Sympatex film and waterborne polyurethane glue. The specific preparation method is as follows: The glass fiber and aramid fiber are respectively immersed in the solution of polyurethane glue so that the polyurethane glue can fully penetrate the fiber surface to form a preliminary bond. After immersion, the fibers are taken out and cured. The polyurethane glue is cured by natural drying for 24 hours to ensure full penetration. Then, the treated glass fiber, Sympatex film, and treated aramid fiber are stacked in sequence, and finally hot-pressed for 6 minutes at 130 °C and a pressure of 12 MPa through a hot-pressing device to enable effective bonding between the layers and form an integral waterproof and sealing composite fabric.

[0058] The mesh support is prepared by compounding 55% polypropylene fiber and 45% modified loofah sponge. The specific preparation method is as follows: The loofah sponge is cut into segments with a size controlled between 1 and 5 cm. The loofah sponge segments are added to the mixed aqueous solution of chloroprene rubber latex and VAE emulsion (volume ratio 1:1) and soaked, and then taken out for hot-pressing treatment; the temperature of the hot press is controlled between 120 °C, a pressure of 2 MPa is applied, and it is compressed for 15 minutes. During the hot-pressing process, a multi-layer structure is formed by synchronously compounding thermoplastic polyurethane material with modified loofah sponge fibers and polypropylene fibers, that is, a mesh support with good mechanical properties, thermal stability, and aging resistance is obtained.

[0059] This embodiment also provides a preparation method of the CCS-based environment-friendly oxygen isolation and fire prevention material, as well as a usage method of applying the CCS-based environment-friendly oxygen isolation and fire prevention material to the oxygen isolation of surface fissures in shallow buried coal seams, which are specifically as follows:

[0060] 1) On the basis of prefabricating the above materials, lay the waterproof and sealed composite fabric, ensure it is flat and without wrinkles, apply acrylic adhesive, arrange the intermediate mesh supports at uniform intervals, and ensure they are firmly fixed on the waterproof and sealed composite fabric; after arranging both the waterproof and sealed composite fabric and the intermediate mesh supports, fill with the solid waste-based self-foaming carbon capture material, evenly fill the entire space of the mesh supports with the mixed gelling material, and ensure the density; after completing the filling of the gelling material, lay the permeable and wear-resistant cover, and fix it to the mesh supports through acrylic adhesive, then the environment-friendly oxygen isolation and fire prevention material is obtained; finally, roll up the fixed oxygen isolation material and package it for standby.

[0061] 2) The environment-friendly oxygen isolation and fire prevention material is applied to seal the surface fissures of shallow-buried coal seams (such as Figure 2 ):

[0062] First, before sealing the surface fissures of the shallow-buried coal seam and storing CO2, evaluate the environmental impact of the air leakage area to ensure that it will not cause negative impacts on the surrounding ecosystem. Then conduct a detailed investigation and evaluation of the corresponding goaf and surface fissures to determine the depth, width and distribution of the fissures, providing a basis for the subsequent filling plan. According to the survey results, determine the specific locations where the oxygen isolation material needs to be filled.

[0063] Secondly, according to the size and coverage area of the on-site fissures, confirm the specifications of the oxygen isolation material, prepare the necessary construction tools, check the surface humidity before laying the oxygen isolation material, and if it is too wet, wait for the surface to dry naturally. At the same time, before implementing the surface crack sealing in the air leakage area of the surface fissures of the shallow-buried coal seam after investigation, clean and treat the surface around the sealing area to ensure good adhesion of the environment-friendly oxygen isolation material. After cleaning, it is necessary to ensure that the surface is dry and free of impurities, and use concrete filling materials to seal the larger or obvious fissures to enhance the bonding effect of the oxygen isolation material.

[0064] Then, according to the previous investigation and evaluation results, lay the environment-friendly oxygen isolation material flat in the designated area, ensure sufficient coverage area, and closely combine it with the surrounding soil. Use mechanical fixing devices (such as nails, screws, etc.) to fix it to the ground to prevent its displacement, and then inject water into the oxygen isolation material several times so that the solid waste-based self-foaming carbon capture material can naturally foam and cure inside the on-line pile structure. The water injection interval is kept at 3 h / time, and the number of water injection times is 8 times. For larger fissures, overlapping laying can be carried out if necessary to ensure that the material can form a complete oxygen isolation barrier to prevent the penetration of oxygen.

[0065] Next, the CO2 captured by the coal-fired power plant in the factory and mining area is transported to the goaf area below the surface fissure through drilling or pipelines. After sealing, a closed space can be formed between the goaf and the surface to store CO2. At the same time, this oxygen isolation material can also absorb and block the CO2 escaping from the goaf to the air leakage channel, thereby achieving multiple effects of synergistically reducing pollution and carbon emissions and inerting the spontaneous combustion environment of the coal in the goaf.

[0066] Finally, parameters such as the oxygen concentration, temperature, and pressure in the goaf of the technical implementation area are monitored in real time through sensors to ensure the effectiveness of the oxygen isolation barrier. Regular inspections are carried out on the filled environment-friendly oxygen isolation material to evaluate its structural integrity and oxygen isolation effect. If defects are found, the material should be replenished or maintained in a timely manner. If a high temperature or oxygen concentration is found in the goaf, to ensure safety, the emergency response procedure should be quickly activated, and the rapid reaction ability of the oxygen isolation material should be used to carry out local isolation again to slow down the rate of coal oxidation and temperature rise.

[0067] Evaluation of the implementation effect and performance of the fissure oxygen isolation in Example 1:

[0068] Before testing the implementation effect of leak stoppage, oxygen isolation, and fire prevention in a specific mining area, the performance of the components of the environment-friendly oxygen isolation and fire prevention material was first characterized and tested. The performance test methods mainly include: measuring the water permeability of the material using a hydrostatic water permeability test, obtaining the wear resistance of the material through a Martindale abrasion tester; measuring its tensile strength using a tensile testing machine, which should not be less than 15 MPa to ensure that the material can remain stable under load; conducting a tear strength test using a tear testing machine; analyzing its ultraviolet resistance using an ultraviolet accelerated aging tester after 200 hours of ultraviolet irradiation; and measuring the temperature resistance of the material in the temperature range of -20°C to 60°C. The measurement results are shown in Table 1.

[0069] Table 1 Measurement results of material performance parameters

[0070]

[0071] The test results of the water-permeable and wear-resistant cover show that the water permeability of this material is 1000 L / (m 2· h) Above, it can ensure the smoothness of water injection; after 1000 times of abrasion, the wear rate is 12%, ensuring that the surface material is not easily worn and extending the service life; the tensile strength is 17 MPa, ensuring that the material can remain stable under load; the tear strength should reach 45 N, ensuring that the material has good tear resistance and can adapt to underground conditions; the wear rate is 8%, ensuring the durability of the material; after being treated at 70 °C for a certain time, its tensile strength remains at about 85% of the original value; after 200 hours of ultraviolet irradiation, the tensile strength decreases by 10%, indicating that the material can adapt to the environment under sunlight; after a certain time at a temperature range of -20 °C to 60 °C, the tensile strength of the material remains at about 92% of its own. Thus, it can be seen that this permeable and wear-resistant cover meets the application requirements of preventing air leakage and plugging in surface fissures of shallow-buried coal seams during the process of preparing oxygen-isolating materials and has good market prospects.

[0072] The waterproof ability of the waterproof and sealed composite fabric was measured by a water pressure test under the condition of 1 m water column, and the remaining test methods refer to the performance test methods of the permeable and wear-resistant cover. The water permeability results of the waterproof and sealed composite fabric show that this oxygen-isolating material can still avoid the troubles caused by moisture in a closed environment, and there is no leakage problem at the bottom; the tensile strength is 30 MPa, ensuring stable use even under load; the tear strength should reach 65 N, which can prevent the material from being torn due to external forces during use. The wear rate is 8%, ensuring the durability of the material; after being treated at 70 °C for a certain time, its tensile strength remains at about 85% of the original value; in addition, after 200 hours of ultraviolet irradiation, the tensile strength decreases by 12%. Thus, it can be seen that this waterproof and sealed composite fabric fully meets the application requirements of preventing air leakage and plugging in surface fissures of shallow-buried coal seams, can play an effective role in preventing air leakage and water leakage during actual construction, and ensure the safety and stability of the coal seam.

[0073] For the solid waste-based self-foaming carbon capture material, the compressive strength, density, water permeability, air leakage prevention performance, etc. of the material were mainly measured. The specific test methods include using a universal testing machine to test the compressive strength; calculating the density by measuring the volume and mass of the sample; using a water permeability tester to measure its water permeability; measuring the gas leakage rate under specific pressure and time. The test results are shown in Table 2. The results show that the compressive strength of the solid waste-based self-foaming carbon capture material can meet the bearing capacity and stability of the material under load, its density can meet the requirements of light weight and good heat insulation performance, the water permeability rate is low, the material can effectively prevent water penetration, and it is suitable for use in humid environments; the air leakage rate is less than 0.1 L / min·m 2 , which can effectively prevent gas leakage.

[0074] Table 2 Performance measurement results of solid waste-based self-foaming carbon capture material

[0075] Parameter Compressive strength Density Water permeability Air leakage prevention Test result 2.0MPa <![CDATA[700kg / m 3 > <![CDATA[0.05L / (m 2 ·h)]]> <![CDATA[0.05L / min·m 2 >

[0076] After the prefabricated oxygen isolation material is injected with water and solidified, comparing the performance parameters of the commonly used foamed gelling material, as shown in Table 3, it is found that the environmentally friendly oxygen isolation and fire prevention material performs well in terms of compressive strength and impermeability, and its low shrinkage rate makes it more advantageous in anti-seepage plugging.

[0077] Table 3 Performance determination results of oxygen isolation material and foamed gelling material

[0078] Parameter Compressive strength Tensile strength Impermeability Shrinkage rate Oxygen barrier material 4.6MPa 3.5MPa 1×10^-9cm / s 0.05％ Foamed cementitious material 1.9MPa 1.5MPa 1×10^-8cm / s 0.2％

[0079] A certain mine is a shallowly buried close-distance coal seam group. The whole minefield is divided into five panels. When conducting on-site evaluation and investigation, a handheld GPS recorder is used to locate the fissures and record their coordinates; a compass is used to identify the extension direction of the fissures, and a tape measure is used to measure the width, depth and spacing of the fissures. After testing, it is found that the surface fissures of this mine are divided into collapse fissures and graben fissures. These two types of fissures are located on the surface between the two main roadways of the coal mining face and directly above the goaf behind the working face respectively. The fissures always exist with the continuous mining of the working face, which promotes the process of spontaneous combustion of coal in the goaf. Therefore, it is necessary to take corresponding measures to prevent and control the spontaneous combustion of coal in the goaf against the air leakage of the surface fissures of this mine.

[0080] Through monitoring, it is found that coal oxidation and temperature rise are occurring in the goaf directly below the surface fissure in a certain panel, and the CO concentration reaches 250 ppm, indicating that there is a certain hidden danger of spontaneous combustion of the remaining coal in this area of the goaf. In order to efficiently prevent and control the formation of coal spontaneous combustion disasters in the goaf of the shallowly buried coal seam working face, this mine adopts the preparation and application method of the environmentally friendly oxygen isolation and fire prevention material based on CCS proposed in the present invention, combined with the appendix Figure 1 and Figure 2 , the specific steps are as follows:

[0081] First, conduct on-site exploration and fissure positioning of the surface fissures of this mine. Conduct a comprehensive exploration of the surrounding area of the coal mine, locate the specific position and morphological characteristics of the surface fissures, and evaluate the air leakage intensity. At the same time, prepare the oxygen isolation material, prefabricate the oxygen isolation material that meets the engineering requirements according to the material ratio required by the present invention, and ensure its good compressive strength and water resistance to ensure the stability and durability in the later application.

[0082] Secondly, apply oxygen isolation materials at the surface fissures, fully cover the fissures with the oxygen isolation materials, and use mechanical or manual methods to ensure good contact between the oxygen isolation materials and the ground to achieve a good sealing effect. After the fixation work is completed, inject water into the oxygen isolation materials several times to enable the waste-based self-foaming carbon capture material to naturally foam and cure inside the on-line pile structure. The water injection interval is maintained at 3 h / time, and the number of water injection times is 9 times. For larger fissures, overlapping laying can be carried out if necessary to ensure that the materials can form a complete oxygen isolation barrier to prevent the penetration of oxygen.

[0083] Next, after the plugging is completed, inject CO2 into the closed space to ensure that CO2 can be fully distributed in the goaf. The CO2 captured by the coal-fired power plant in the factory and mining area is transported to the goaf area where the surface fissures are plugged through drilling or pipelines. The plugged goaf can form a closed space to store CO2. At the same time, the oxygen isolation materials can also absorb and block the CO2 escaping from the goaf to the air leakage channel, thereby achieving multiple effects of solid waste utilization, CO2 mineralization and storage, and reducing the oxygen concentration in the goaf, and realizing the purpose of reducing pollution and carbon emissions and treating disasters with waste.

[0084] Finally, after the construction is completed, regularly detect the sealing effect of the fissures and establish a gas system. Combining the leak-proof effect of the oxygen isolation materials, use sensors to monitor parameters such as the oxygen concentration, CO concentration, and CO2 concentration in the goaf in real time to ensure the effectiveness of the closed barrier. Regularly check the filled environmental protection oxygen isolation materials to evaluate their structural integrity and oxygen isolation effect. If defects are found, supplement or maintain the materials in time. If too high temperature or oxygen concentration is found in the goaf, to ensure safety, the emergency response procedure should be quickly activated, and the rapid reaction ability of the high-toughness oxygen isolation materials should be used to carry out local isolation again to slow down the rate of coal oxidation and temperature rise.

[0085] During the implementation of the preparation and application method of the environmentally friendly oxygen isolation and fire prevention material based on CCS of the present invention in this mining area, corresponding monitoring is required for aspects such as the prevention and control of coal spontaneous combustion in the goaf, the sealing of the effective CO2 storage space, and the absorption of the escaped CO2. In order to evaluate the plugging effect and related fire prevention and storage performance, before and after the plugging, oxygen sensors and CO2 sensors can be used to regularly record the concentration data of oxygen, CO, and CO2 for comparative analysis. The following are specific examples of the relevant sensor layout, monitoring data, and their changes.

[0086] An oxygen sensor is arranged at the goaf entrances above and below the plugging area respectively to monitor the change of oxygen concentration before and after plugging; a CO sensor is arranged at the return air corner of the working face to monitor the change of carbon monoxide concentration. CO2 sensors are respectively arranged at the edge of the oxygen isolation material (peripheral plugging area), below the oxygen isolation material and the CO2 injection port inside the goaf to monitor the CO2 concentration in the goaf, so as to ensure the monitoring of CO2 leakage and the concentration change in the storage area. Compare the data of the gas sensors before and after plugging, analyze the change trend of oxygen concentration and CO2 concentration, and confirm the CO2 storage effect and whether there is a spontaneous combustion risk in the goaf.

[0087] By monitoring the change of the concentrations of oxygen, CO and CO2, it is found that before the application of the technology of the present invention, the volume concentration of oxygen above the surface fissure is monitored to be 21%, the oxygen at the goaf entrance is 19%, and at the same time, the CO concentration at the return air corner of the working face is 260 ppm, the CO2 concentrations at the edge of the oxygen isolation material (peripheral plugging area) and below the oxygen isolation material are about 0.04%, and the CO2 concentration inside the goaf is about 0.1%. This shows that there is a certain risk of coal spontaneous combustion in the goaf below the surface fissure area. After 72 hours of implementing the preparation method and application method of the CCS-based environment-friendly oxygen isolation and fire prevention material of the present invention, it is monitored that the volume concentration of oxygen above the surface fissure is significantly reduced to 14%, the oxygen at the goaf entrance is 12%, the CO2 concentration at the edge of the oxygen isolation material (peripheral plugging area) is about 0.04%, the CO2 concentration below the oxygen isolation material is about 1.5%, and at the same time, the CO concentration at the return air corner of the working face is 25 ppm, and the CO2 concentration inside the goaf is 2.5%. In addition, it is monitored that one week after implementing the fire prevention technology of the present invention, the CO2 concentration in the closed space is 3% and tends to be stable.

[0088] It is comprehensively concluded that the significant reduction of oxygen concentration indicates that the fire prevention technology of the present invention effectively reduces the infiltration of external air, reduces the oxidation risk of the goaf, and helps to prevent and control coal spontaneous combustion. The CO concentration gradually decreases to 20 ppm, indicating that the coal oxidation and temperature rise process in the goaf after plugging is effectively controlled and the potential safety hazard is reduced. The change results of the CO2 concentrations at the edge of the oxygen isolation material (peripheral plugging area) and inside the goaf show the effective storage of the injected CO2 in the closed space, indicating that the material can form an effective storage space, further reduce the oxygen concentration, and thus reduce the coal oxidation risk. In addition, the change of the CO2 concentrations at the edge of the oxygen isolation material (peripheral plugging area) and below the oxygen isolation material shows that during the implementation of the technology of the present invention, the solid waste-based self-foaming carbon capture material can effectively absorb and mineralize the CO2 gas leaked from the storage space, and further indicates the effectiveness of the implementation of the technology of the present invention in preventing and controlling the coal spontaneous combustion caused by the leakage of air through the surface fissures in the shallowly buried coal seam and realizing CO2 storage, providing an effective theoretical basis and practical reference for future coal seam safety management.

[0089] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and various changes or modifications can be made to this embodiment without departing from the principle and essence of the present invention. The protection scope of the present invention is only defined by the appended claims.

Claims

1. A method for preparing an environmentally friendly oxygen-isolating fire-extinguishing material based on CCS, characterized in that: The following steps are involved: Step 1), material prefabrication; ①Prefabricated water-permeable and wear-resistant cover Spandex, polyester fiber and polypropylene fiber are blended to form a fabric, and then polyurethane is coated on the surface of the fabric and cured to obtain a water-permeable and wear-resistant cover; ②Prefabricated waterproof sealing composite fabric The glass fiber with a diameter of 9-13 μm and the aramid fiber with a diameter of 12-15 μm are respectively immersed in a solution of polyurethane glue, then taken out, dried and solidified; the treated glass fiber and the aramid fiber are respectively laid on both sides of a Sympatex film with a thickness of 10-20 μm, and then subjected to heat pressing to obtain a waterproof sealing composite fabric with a three-layer structure; ③ Prefabricated solid waste-based self-foaming carbon capture materials Steel slag, slag, fly ash, desulfurized gypsum, modified starch-based foaming agent, coconut oil amide, xanthan gum and water are uniformly mixed to obtain a solid waste-based self-foaming carbon capture material, wherein the modified starch-based foaming agent is obtained by compounding corn starch and water glass; ④Prefabricated mesh bracket The loofah is cut into segments of 1 to 5 cm in size, and is added into a mixed aqueous solution of a chloroprene emulsion and a VAE emulsion for immersion treatment to modify the loofah to obtain modified loofah fibers; then the temperature of a hot press is controlled to be 100 to 150° C., and a pressure of 1 to 5 MPa is applied for hot pressing treatment to melt-bond the thermoplastic polyurethane material with the modified loofah fibers and the polypropylene / polyester fibers to form a multilayer structure to obtain a mesh support; Step 2), composite assembly of prefabricated materials; Firstly, a waterproof sealing composite fabric is laid as the bottom surface, and mesh brackets are evenly spaced on the waterproof sealing composite fabric and fixed with adhesive; then, the solid waste-based self-foaming carbon capture material is filled in the frame formed by the mesh bracket so that it is evenly filled in the entire space of the mesh bracket; finally, a water-permeable and wear-resistant cover is laid as the top surface and fixed with the mesh bracket with adhesive, thus obtaining an environmentally friendly oxygen-isolating and fire-extinguishing material based on CCS.

2. The method for preparing the environmentally friendly oxygen-isolating and fire-extinguishing material based on CCS according to claim 1, characterized in that: The raw materials of the water-permeable and wear-resistant cover are: textile solid waste spandex accounts for 10-15wt%, polyester fiber accounts for 40-55wt%, and polypropylene fiber accounts for 30-50wt%; the coating amount of polyurethane accounts for 10-14% of the total mass of the fiber.

3. The method for preparing the environmentally friendly oxygen-isolating and fire-extinguishing material based on CCS according to claim 1, characterized in that: Among the fiber raw materials used in the waterproof sealing composite fabric, the mass proportion of aramid fiber is 45%-55%, and the mass proportion of glass fiber is 55%-45%.

4. The method for preparing the environmentally friendly oxygen-isolating and fire-extinguishing material based on CCS according to claim 1, characterized in that: The raw material components of the solid waste-based self-foaming carbon capture material are prepared according to the following weight: 30-40 parts of steel slag, 25-35 parts of slag, 15-25 parts of fly ash, and 5-10 parts of desulfurized gypsum; the mass of the modified starch-based foaming agent and coconut oil amide accounts for 3%-5% of the total mass of the solid waste-based self-foaming carbon capture material; the mass ratio of the modified starch-based foaming agent to the coconut oil amide is 4:1, and the modified starch-based foaming agent is obtained by compounding corn starch and water glass in a mass ratio of 1:0.3; the amount of xanthan gum is 0.1%-0.3% of the total mass of the modified starch-based foaming agent and coconut oil amide; and the water-solid ratio is 0.4-0.

5.

5. The method for preparing the environmentally friendly oxygen-isolating and fire-extinguishing material based on CCS according to claim 1, characterized in that: The mesh support is composed of 35-45% by weight of modified loofah fibers and 55-65% by weight of polypropylene / polyester fibers, which are melt-bonded by adding 15% of thermoplastic polyurethane.

6. The method for preparing the environmentally friendly oxygen-isolating and fire-extinguishing material based on CCS according to claim 1, characterized in that: When the waterproof sealing composite fabric is prefabricated, the hot pressing process is: hot pressing for 5-10 minutes at 120-150° C. and a pressure of 10-15 MPa by a hot pressing device.

7. An environmentally friendly oxygen-isolating fire-extinguishing material based on CCS, characterized in that: The method is prepared by any one of claims 1 to 6.

8. An application of the CCS-based environmentally friendly oxygen-isolating fire-extinguishing material according to claim 7 to prevent and control spontaneous combustion of coal in goaf areas of shallow buried coal seams, characterized in that: The environmentally friendly oxygen-isolating and fire-proofing material is spread out to completely cover the surface cracks of the shallow buried coal seam, and then water is injected into the environmentally friendly oxygen-isolating and fire-proofing material so that the solid waste-based self-foaming carbon capture material can naturally foam and solidify inside the structure of the mesh support.

9. The use according to claim 8, characterized in that: The interval between water injections is maintained at 2-3h / time, and the number of water injections is 8-10 times.

10. The use according to claim 8, characterized in that: The environmentally friendly oxygen-isolating and fire-proofing materials are spread out to completely cover the surface cracks of the shallow buried coal seam, and the environmentally friendly oxygen-isolating and fire-proofing materials are fixed to the ground using mechanical fixing devices, wherein the mechanical fixing devices are nails, screws or anchor bolts.

Images