Preparation method of solid waste-based filling material for compressed air energy storage pipeline

Abstract

The invention discloses a preparation method of a solid waste-based filling material for a compressed air energy storage pipeline, which comprises the following steps: (1) mixing ferrosilicon slag powder with acid liquor, heating and extracting, and carrying out solid-liquid separation to obtain extracted slag and extracted liquor; and uniformly mixing carbon powder prepared from waste activated carbon with the leaching solution, then adding alkali liquor to neutralize to be neutral, then heating and evaporating to dryness, and grinding a solid product to obtain the modified carbon powder. And (2) mixing the leaching residues with modified carbon powder, carrying out graphitization treatment, and crushing the obtained solid product to obtain the rigid filling particulate matter. And (3) uniformly mixing a waste organic elastomer and the graphitized modified carbon powder, heating and mixing, and extruding and pelletizing to obtain the elastic filling particulate matter. And uniformly mixing the filling particles with the rigid filling particles to obtain the filling material. The filling material prepared by the invention not only can well avoid damage to the pipeline caused by collapse of the cavern, but also can well adapt to deformation of the pipeline and reduce friction between the cavern and the pipeline.

Description

Technical Field

[0001] The present invention relates to the technical field of compressed air energy storage, and in particular to a method for preparing a solid waste-based filling material for a compressed air energy storage pipeline. Background Art

[0002] Compressed air energy storage technology is a new type of energy storage technology that transfers excess electrical energy into compressed air and stores the compressed air in a container so that it can be released and converted into electrical energy when needed. This energy storage technology is cleaner and does not produce secondary pollutants or greenhouse gas emissions. It is a sustainable way of energy storage. At present, high-strength pipes are generally used to store compressed air. These pipes are usually installed in underground tunnels to ensure safety and avoid leakage. However, traditional underground tunnel construction is not only costly, but also has a long construction period. In order to solve the above problems, the researchers proposed to use abandoned mines, salt caverns and other underground caverns instead of artificially constructed underground tunnels for the placement of compressed air storage pipelines, which can not only realize the resource utilization of these underground caverns, but also help reduce the construction cost of compressed air energy storage technology.

[0003] However, since these abandoned underground caverns have the risk of collapse during use, which in turn causes damage to the compressed air storage pipeline, there is a safety hazard when the pipeline is directly installed in such caverns. The inventors have found that although filling the space between the outside of the pipeline and the cavern with materials such as gravel can help reduce / mitigate direct damage to the pipeline. However, the filling / deflating process will cause the pipeline itself to expand or contract to a certain extent, causing friction between the outer wall of the pipeline and the filling materials such as gravel. Multiple accumulations can easily cause damage to the anti-corrosion layer of the outer wall of the pipeline, leading to pipeline corrosion. The reduced strength of these parts can easily lead to rupture and leakage of the pipeline under the high pressure of compressed air. Summary of the invention

[0004] In view of the above problems, the present invention provides a method for preparing a solid waste-based filling material for a compressed air energy storage pipeline. The filling material can not only effectively avoid the damage to the pipeline caused by cavern collapse, but also can well adapt to pipeline deformation and reduce friction between the two, thereby avoiding damage to the pipeline and increasing its service life. Specifically, the technical solution of the present invention is as follows.

[0005] A method for preparing a solid waste-based filling material for a compressed air energy storage pipeline comprises the following steps: (1) Mix ferrosilicon slag powder with acid solution and heat to extract. After completion, separate the solid and liquid to obtain extraction slag and extraction solution. Mix the carbon powder made from waste activated carbon with the extraction solution, add alkali solution to neutralize to neutrality, heat and evaporate to dryness, grind the solid product to obtain modified carbon powder.

[0006] (2) The leached residue is mixed with the modified carbon powder and graphitized in a protective atmosphere. After the graphitization is completed, the mixture is cooled to room temperature and the obtained solid product is crushed to obtain rigid filling particles.

[0007] (3) The modified carbon powder of step (1) is graphitized in a protective atmosphere, and after the graphitization is completed, the obtained graphite powder is mixed with the waste organic elastomer powder and heated to melt for kneading, and after the graphitization is completed, the elastic filling particles are extruded and pelletized, and after cooling, the elastic filling particles are obtained. The elastic filling particles are mixed evenly with the rigid filling particles to obtain the solid waste-based filling material.

[0008] Furthermore, in step (1), the fineness of the ferrosilicon slag powder is 100-200 mesh.

[0009] Furthermore, in step (1), the ratio of the ferrosilicon slag to the acid solution is 1 g: 15-35 ml. Optionally, the mass fraction of the acid solution is 10-20%.

[0010] Furthermore, in step (1), the acid solution includes at least one of sulfuric acid, nitric acid, etc.

[0011] Furthermore, in step (1), the heating temperature is 50-60° C., and the extraction time is 2-4 hours.

[0012] Furthermore, in step (1), the ratio of the carbon powder to the extract is 1:5~12ml.

[0013] Furthermore, in step (1), the alkaline solution includes at least one of sodium hydroxide, potassium hydroxide, ammonia water, sodium carbonate, potassium carbonate, etc.

[0014] Furthermore, in step (1), the heating temperature is 90-120° C., and the heating is performed at this temperature until the mass is constant.

[0015] Furthermore, in step (1), the fineness of the modified carbon powder is 300-500 mesh.

[0016] Furthermore, in step (2), the mass ratio of the leached residue to the modified carbon powder is 1:0.2-0.26.

[0017] Furthermore, in steps (2) and (3), the graphitization treatment is carried out at a temperature of 1620-1800°C, for 6-10 hours, and at a pressure of 0.3-0.8 MPa. Optionally, the protective atmosphere includes nitrogen, argon, etc.

[0018] Furthermore, in step (2), the particle size distribution of the rigid filling particles is between 0.5 and 1.5 cm.

[0019] Furthermore, in step (3), the graphite powder is 25-36% of the mass of the rubber powder. Optionally, the fineness of the organic elastomer powder is 80-150 mesh.

[0020] Furthermore, in step (3), the organic elastomer includes any one of: styrene-butadiene-styrene block copolymer (SBS), polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (SEBS), thermoplastic dynamic vulcanized rubber (TPV), thermoplastic polyurethane elastomer rubber (TPU), etc.

[0021] Furthermore, in step (3), the particle size distribution of the elastic filling particles is between 0.5 and 1.5 cm.

[0022] Furthermore, in step (3), the mass ratio of the elastic filling particles to the rigid filling particles is 1:3-4.5.

[0023] Compared with the prior art, the present invention has at least the following beneficial technical effects: The present invention adopts the rigid filling particles and the elastic filling particles as filling materials. After filling them in the space between the outer wall of the compressed air pipeline and the abandoned mine, it can not only provide good rigid support to resist the collapse of the mine, but also absorb and reduce the impact caused by the collapse, and disperse the impact more evenly on the outer wall of the pipeline, which well prevents damage to the pipeline. At the same time, due to the deformation effect of the elastic filling particles, the filling material as a whole has a certain deformation effect, so that the filling material can well adapt to the expansion or contraction deformation of the volume of the pipeline during the filling / deflating process, so that when the filling material is filled between the outer wall of the pipeline and the abandoned mine, the need for pipeline volume deformation can still be met, ensuring the normal operation of the pipeline. In addition, the filling material and the pipeline also have a good lubrication and friction reduction effect, which can effectively reduce the friction between the pipeline and the filling material during the volume deformation process, and reduce the damage of the rigid filling particles to the outer wall of the pipeline. At the same time, the good lubrication and wear reduction effect between the elastic filling particles and the rigid filling particles and the pipeline can effectively coordinate the expansion or contraction of the filling material volume caused by the deformation of the pipeline volume, so that the filling material can always be tightly filled in the space outside the pipeline, providing a good extrusion support effect on the mine, and helping to prevent and reduce the damage caused by collapse. To this end, the present invention uses ferrosilicon slag as a raw material to extract the iron element therein, and mixes the obtained leaching solution with carbon powder made of waste activated carbon and then converts it into a modified carbon powder containing iron hydroxide with alkali solution. Then the leached slag and the modified carbon powder are graphitized to prepare rigid filling particles. In this process, the hydroxide decomposes in the early stage of graphitization heating to form iron oxide, which further acts as a catalyst to reduce the barrier of the carbon powder to graphite, thereby reducing the formation temperature of graphite. At the same time, in the graphitization process, the ferrosilicon slag is also melted and mixed with the formed graphite, so that the characteristics of ferrosilicon slag and waste activated carbon are used to not only convert them into rigid filling particles with self-lubricating and wear-reducing effects, but also reduce the formation temperature of graphite, reduce energy consumption, and realize solid waste utilization. At the same time, the present invention also prepares elastic filling particles with waste organic elastomer after graphitization treatment of the modified carbon powder. In this process, the iron oxide formed by the iron hydroxide contained in the modified carbon powder not only plays a role in reducing the barrier of the transformation of carbon powder into graphite, but also has the effect of improving the heat resistance of the elastomer. In addition, since the iron oxide can also improve the dispersibility of graphite powder and reduce its agglomeration in the elastomer, the heat resistance of the elastic filling particles can be better improved, the problem of aging of the organic matrix in the elastic filling particles caused by the increase of the closing temperature of the pipeline during the inflation process can be reduced, and the service life can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 This is a sample picture of the modified carbon powder prepared in the following Example 1.

[0026] Figure 3 This is a sample picture of the rigid filling particles prepared in Example 1 below.

[0027] Figure 2 This is a sample picture of graphite powder prepared using modified carbon powder in the following Example 1.

[0028] Figure 4 This is a sample picture of the elastic filling particles prepared in the following Example 1. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0030] Unless otherwise defined, all professional and scientific terms used in the present invention have the same meanings as those familiar to those skilled in the art. The reagents or raw materials used in the present invention can be purchased through conventional channels. If there are no special instructions, the reagents or raw materials used in the present invention are used in a conventional manner in the art or in accordance with the product instructions. In addition, any method and material similar to or equivalent to the described content can be applied to the method of the present invention. Now, the technical solution of the present invention is further described in conjunction with the accompanying drawings and specific embodiments of the specification.

[0031] Example 1 A method for preparing a solid waste-based filling material for a compressed air energy storage pipeline comprises the following steps: (1) Mix 100-mesh ferrosilicon slag powder and 17% sulfuric acid in a ratio of 1g:20ml, then heat to 50°C in a water bath for 4 hours for leaching, stirring continuously during the process. After completion, filter to obtain leaching residue and leaching solution respectively.

[0032] (2) The carbon powder prepared from the waste activated carbon and the extract are mixed in a ratio of 1:8 ml and stirred evenly. Then, sodium hydroxide solution is added until neutralized and heated to 110° C. and evaporated to dryness. The obtained solid product is ground and passed through a 400-mesh sieve to obtain the following: Figure 1 Modified carbon powder shown.

[0033] (3) The leached residue and the modified carbon powder were mixed in a mass ratio of 1:0.23 and stirred evenly, and then placed in a heating furnace in a nitrogen atmosphere and heated to 1720°C for 9 hours for graphitization treatment, and the pressure was set to 0.5 MPa. After completion, the solid product was cooled to room temperature, and the obtained solid product was crushed and sieved to obtain rigid filling particles with a particle size distribution between 0.5 and 1.5 cm (such as Figure 2 as shown).

[0034] (4) The modified carbon powder of step (1) is placed in a heating furnace in a nitrogen atmosphere and heated to 1720°C for 9 hours for graphitization treatment. The pressure is set to 0.5 MPa. Figure 3 The graphite powder is mixed with the waste thermoplastic dynamic vulcanized rubber (TPV101-80) powder with a fineness of 120 mesh, wherein the graphite powder accounts for 30.4% of the mass of the rubber powder, and then the mixed powder is heated until the rubber powder is melted and then kneaded. After completion, it is extruded and pelletized, and after cooling, an elastic filling granular material with a particle size distribution between 0.8 and 1.1 cm (such as Figure 4 As shown). The solid waste-based filling material is uniformly mixed with the rigid filling particles in a mass ratio of 1:4 to obtain a solid waste-based filling material.

[0035] Performance test: (1) The solid waste-based filling material prepared in this embodiment is loaded into a container and compacted to form a flat upper surface that is higher than the container. A steel plate is then placed on the upper surface, and a weight is placed at the center of the steel plate to apply a normal pressure. The normal pressure applied by the steel plate and the weight is recorded as G. The steel plate is then pulled horizontally with a tensile gauge, and the pulling force F at this time is recorded. The ratio of the pulling force F to the G is the friction coefficient. The smaller the value, the higher the lubrication and wear reduction performance of the solid waste-based filling material prepared in this embodiment. (2) The heat aging resistance of the elastic filling particles prepared in this embodiment was tested according to "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber" (GB / T 528-2009), that is, the rubber extruded in step (4) was made into a test specimen, and then the tensile strength and elongation at break before and after heat aging treatment (170°C for 96 hours) were tested, and the decline rate of these two test indicators was calculated. The smaller the decline, the higher the heat aging resistance of the elastic filling particles. The results are shown in the following table: .

[0036] Example 2 A method for preparing a solid waste-based filling material for a compressed air energy storage pipeline comprises the following steps: (1) Mix 200-mesh ferrosilicon slag powder and 10% nitric acid by mass at a ratio of 1g:35ml, then heat to 60°C in a water bath for 3 hours for leaching, stirring continuously during the process. After completion, filter to obtain leaching residue and leaching solution respectively.

[0037] (2) The carbon powder made from the waste activated carbon and the leaching solution are mixed in a ratio of 1:5 ml and stirred evenly, and then sodium hydroxide solution is added until neutralized and heated to 90° C. and evaporated to dryness. The obtained solid product is ground and passed through a 300-mesh sieve to obtain modified carbon powder.

[0038] (3) The leached residue and the modified carbon powder are mixed in a mass ratio of 1:0.2 and stirred evenly, and then placed in a heating furnace in a nitrogen atmosphere and heated to 1620°C for 10 hours for graphitization treatment, and the pressure is set to 0.8 MPa. After completion, the mixture is cooled to room temperature, and the obtained solid product is crushed and sieved to obtain rigid filling particles with a particle size distribution between 0.5 and 1.5 cm.

[0039] (4) The modified carbon powder of step (1) is placed in a heating furnace in a nitrogen atmosphere and heated to 1620°C for 10 hours for graphitization treatment, and the pressure is set to 0.8MPa. After completion, the obtained graphite powder is mixed with waste thermoplastic dynamic vulcanized rubber (TPV101-80) powder with a fineness of 150 mesh, and the graphite powder is 25% of the mass of the rubber powder. Then the obtained mixed powder is heated until the rubber powder is melted and then kneaded. After completion, it is extruded and pelletized. After cooling, an elastic filling particle with a particle size distribution between 1.2 and 1.5 cm is obtained. It is mixed evenly with the rigid filling particle in a mass ratio of 1:3 to obtain a solid waste-based filling material.

[0040] The friction coefficient of the solid waste-based filling material prepared in this embodiment and the heat aging resistance of the elastic filling particles were tested using the same method as in the above-mentioned embodiment 1. The results are shown in the following table: .

[0041] Example 3 A method for preparing a solid waste-based filling material for a compressed air energy storage pipeline comprises the following steps: (1) Mix ferrosilicon slag powder with a fineness of 180 mesh and sulfuric acid with a mass fraction of 20% at a ratio of 1g:15ml, and then heat to 55℃ in a water bath for 2 hours for leaching, stirring continuously during the process. After completion, filter to obtain leaching residue and leaching solution respectively.

[0042] (2) The carbon powder made from waste activated carbon and the leaching solution are mixed in a ratio of 1:12 ml and stirred evenly, and then sodium hydroxide solution is added until neutralized and heated to evaporate at 120° C. The obtained solid product is ground and passed through a 500-mesh sieve to obtain modified carbon powder.

[0043] (3) The leached residue and the modified carbon powder were mixed in a mass ratio of 1:0.26 and stirred evenly, and then placed in a heating furnace in a nitrogen atmosphere and heated to 1800°C for 6 hours for graphitization treatment, and the pressure was set to 0.3 MPa. After completion, the solid product was cooled to room temperature, and the solid product was crushed and sieved to obtain rigid filling particles with a particle size distribution between 0.5 and 1.5 cm.

[0044] (4) The modified carbon powder of step (1) is placed in a heating furnace in a nitrogen atmosphere and heated to 1800°C for 6 hours for graphitization treatment, and the pressure is set to 0.3MPa. After completion, the obtained graphite powder is mixed with waste thermoplastic dynamic vulcanized rubber (TPV101-80) powder with a fineness of 80 mesh, and the graphite powder is 36% of the mass of the rubber powder. Then, the obtained mixed powder is heated until the rubber powder is melted and then kneaded. After completion, it is extruded and pelletized. After cooling, elastic filling particles with a particle size distribution between 0.5 and 0.9 cm are obtained. It is mixed evenly with the rigid filling particles in a mass ratio of 1:4.5 to obtain a solid waste-based filling material.

[0045] The friction coefficient of the solid waste-based filling material prepared in this embodiment and the heat aging resistance of the elastic filling particles were tested using the same method as in the above-mentioned embodiment 1. The results are shown in the following table: .

[0046] Example 4 A method for preparing a solid waste-based filling material for a compressed air energy storage pipeline. Compared with the above-mentioned embodiment 1, the modified carbon powder of this embodiment is prepared by the following method: (1) Mix ferrosilicon slag powder with a fineness of 100 mesh and clean water in a ratio of 1g:20ml, then heat to 50℃ in a water bath for 4 hours for leaching, stirring continuously during the process. After completion, filter to obtain leaching residue and leaching liquid respectively.

[0047] (2) The carbon powder made from the waste activated carbon and the leaching solution are mixed in a ratio of 1:8 ml and stirred evenly, and then heated to 110° C. for evaporation, and the obtained solid product is ground and passed through a 400-mesh sieve to obtain modified carbon powder.

[0048] The friction coefficient of the solid waste-based filling material prepared in this embodiment and the heat aging resistance of the elastic filling particles were tested using the same method as in the above-mentioned embodiment 1. The results are shown in the following table: .

[0049] Example 5 A method for preparing a solid waste-based filling material for a compressed air energy storage pipeline. Compared with the above-mentioned embodiment 2, the elastic filling particles of this embodiment are prepared by the following method: (1) Mix 200-mesh ferrosilicon slag powder and 10% nitric acid by mass at a ratio of 1g:35ml, then heat to 60°C in a water bath for 3 hours for leaching, stirring continuously during the process. After completion, filter to obtain leaching residue and leaching solution respectively.

[0050] (2) The carbon powder made from the waste activated carbon and the leaching solution are mixed in a ratio of 1:5 ml and stirred evenly, and then sodium hydroxide solution is added until neutralized and heated to 90° C. and evaporated to dryness. The obtained solid product is ground and passed through a 300-mesh sieve to obtain modified carbon powder.

[0051] (3) Mixing the waste thermoplastic dynamic vulcanized rubber (TPV101-80) powder with a fineness of 150 mesh with the modified carbon powder, and the modified carbon powder is 25% of the mass of the rubber powder, and then heating the obtained mixed powder until the rubber powder is melted and kneading, and then extruding and pelletizing, and cooling to obtain elastic filling particles with a particle size distribution between 1.2 and 1.5 cm.

[0052] The friction coefficient of the solid waste-based filling material prepared in this embodiment and the heat aging resistance of the elastic filling particles were tested using the same method as in the above-mentioned embodiment 1. The results are shown in the following table: .

[0053] Example 6 A method for preparing a solid waste-based filling material for a compressed air energy storage pipeline. Compared with the above-mentioned embodiment 1, the rigid filling particles of this embodiment are prepared by the following method: (1) Mix 100-mesh ferrosilicon slag powder and 17% sulfuric acid in a ratio of 1g:20ml, then heat to 50°C in a water bath for 4 hours for leaching, stirring continuously during the process. After completion, filter and obtain the leached slag for use.

[0054] (2) The leached residue was heated to 1720°C in a heating furnace and kept warm for 9 hours, with the pressure set to 0.5 MPa. After completion, the leached residue was cooled to room temperature, and the obtained solid product was crushed and sieved to obtain rigid filling particles with a particle size distribution between 0.5 and 1.5 cm.

[0055] The friction coefficient of the solid waste-based filling material prepared in this embodiment was tested by the same method as in the above-mentioned embodiment 1. The result was a friction coefficient of 0.587. It can be seen that the lubrication and wear reduction effect thereof is significantly reduced compared with that in embodiment 1.

[0056] Example 7 A method for preparing a solid waste-based filling material for a compressed air energy storage pipeline comprises the following steps: (1) Mix 180 mesh ore powder and 20% sulfuric acid in a ratio of 1g:15ml, then heat to 55℃ in a water bath for 2 hours for leaching, stirring continuously during the process. After completion, filter to obtain leached ore powder residue and leaching solution respectively.

[0057] (2) The carbon powder made from waste activated carbon and the leaching solution are mixed in a ratio of 1:12 ml and stirred evenly, and then sodium hydroxide solution is added until neutralized and heated to evaporate at 120° C. The obtained solid product is ground and passed through a 500-mesh sieve to obtain modified carbon powder.

[0058] (3) The leached slag and modified carbon powder are mixed in a mass ratio of 1:0.26 and stirred evenly, and then placed in a heating furnace in a nitrogen atmosphere and heated to 1800°C for 6 hours for graphitization treatment, and the pressure is set to 0.3 MPa. After completion, the solid product is cooled to room temperature, and the solid product is crushed and sieved to obtain rigid filling particles with a particle size distribution between 0.5 and 1.5 cm.

[0059] (4) The modified carbon powder of step (1) is placed in a heating furnace in a nitrogen atmosphere and heated to 1800°C for 6 hours for graphitization treatment, and the pressure is set to 0.3MPa. After completion, the obtained graphite powder is mixed with waste thermoplastic dynamic vulcanized rubber (TPV101-80) powder with a fineness of 80 mesh, and the graphite powder is 36% of the mass of the rubber powder. Then, the obtained mixed powder is heated until the rubber powder is melted and then kneaded. After completion, it is extruded and pelletized. After cooling, elastic filling particles with a particle size distribution between 0.5 and 0.9 cm are obtained. It is mixed evenly with the rigid filling particles in a mass ratio of 1:4.5 to obtain a solid waste-based filling material.

[0060] The friction coefficient of the solid waste-based filling material prepared in this embodiment and the heat aging resistance of the elastic filling particles were tested using the same method as in the above-mentioned embodiment 1. The results are shown in the following table: .

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing solid waste-based filling materials for compressed air energy storage pipelines, characterized in that: The steps include: (1) mixing ferrosilicon slag powder with acid solution and heating for leaching, and after completion, performing solid-liquid separation to obtain leaching slag and leaching solution respectively; mixing carbon powder made from waste activated carbon with the leaching solution, and then adding alkali solution to neutralize to neutrality and heating and evaporating to dryness, and grinding the solid product to obtain modified carbon powder; (2) mixing the leached residue with the modified carbon powder and graphitizing the mixture in a protective atmosphere, cooling the mixture to room temperature, and crushing the obtained solid product to obtain rigid filling particles; (3) The modified carbon powder of step (1) is graphitized in a protective atmosphere, and after the graphitization is completed, the obtained graphite powder is mixed with the waste organic elastomer powder and heated to melt for kneading, and after the graphitization is completed, the powder is extruded and pelletized, and after cooling, the elastic filling particles are obtained; the elastic filling particles are mixed evenly with the rigid filling particles to obtain the solid waste-based filling material.

2. The method for preparing solid waste-based filling materials for compressed air energy storage pipelines according to claim 1, characterized in that: In step (1), the ratio of the ferrosilicon slag to the acid solution is 1 g: 15-35 ml; Optionally, in step (1), the mass fraction of the acid solution is 10-20%; Optionally, in step (1), the fineness of the ferrosilicon slag powder is 100-200 mesh.

3. The method for preparing solid waste-based filling materials for compressed air energy storage pipelines according to claim 1, characterized in that: In step (1), the acid solution includes at least one of sulfuric acid and nitric acid.

4. The method for preparing solid waste-based filling materials for compressed air energy storage pipelines according to claim 1, characterized in that: In step (1), the heating temperature is 50-60° C. and the extraction time is 2-4 hours.

5. The method for preparing solid waste-based filling materials for compressed air energy storage pipelines according to claim 1, characterized in that: In step (1), the ratio of the carbon powder to the extract is 1:5~12ml.

6. The method for preparing solid waste-based filling materials for compressed air energy storage pipelines according to claim 1, characterized in that: In step (1), the alkali solution includes at least one of sodium hydroxide, potassium hydroxide, aqueous ammonia, sodium carbonate, and potassium carbonate; Optionally, in step (1), the heating temperature is 90-120° C., and the mixture is heated at this temperature until the mass is constant; Optionally, in step (1), the fineness of the modified carbon powder is 300-500 mesh.

7. The method for preparing solid waste-based filling materials for compressed air energy storage pipelines according to claim 1, characterized in that: In step (2), the mass ratio of the leached residue to the modified carbon powder is 1:0.2-0.

26.

8. The method for preparing solid waste-based filling materials for compressed air energy storage pipelines according to claim 1, characterized in that: In steps (2) and (3), the graphitization treatment temperature is 1620-1800°C, the time is 6-10 hours, and the pressure is 0.3-0.8 MPa; Optionally, in step (2), the protective atmosphere includes one of nitrogen and argon; Optionally, in step (2), the particle size distribution of the rigid filling particles is between 0.5 and 1.5 cm.

9. The method for preparing solid waste-based filling materials for compressed air energy storage pipelines according to claim 1, characterized in that: In step (3), the graphite powder is 25-36% of the mass of the rubber powder; Optionally, in step (3), the organic elastomer includes: any one of styrene-butadiene-styrene block copolymer, polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, thermoplastic dynamic vulcanized rubber, and thermoplastic polyurethane elastomer rubber; Optionally, in step (3), the fineness of the organic elastomer powder is 80-150 mesh; Optionally, in step (3), the particle size distribution of the elastic filling particles is between 0.5 and 1.5 cm.

10. The method for preparing a solid waste-based filling material for a compressed air energy storage pipeline according to any one of claims 1 to 9, characterized in that: In step (3), the mass ratio of the elastic filling particles to the rigid filling particles is 1:3-4.5.

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