Preparation process of filling material for buried pipe type abandoned mine pressure gas energy storage system

Abstract

The application discloses a preparation process of a filling material for an energy-absorbing and friction-reducing buried pipe type abandoned mine compressed gas energy storage system, and comprises the following steps: (1) sodium stearate and graphite powder are added into hot water and stirred until the sodium stearate is fully dissolved, then graphitized coal gangue particles are added into the obtained liquid phase and ultrasonic treatment is conducted; after the completion, the water in the reaction system is evaporated to obtain pretreated coal gangue particles; (2) the pretreated coal gangue particles are mixed with tetraethoxysilane and then ultrasonic treatment is conducted, and then the mixture is placed in saturated limewater and heated and kept warm to obtain self-lubricating and friction-reducing coal gangue particles; and (3) the self-lubricating and friction-reducing coal gangue particles are uniformly mixed with rubber particles to obtain the filling material. By filling a material layer with an energy-absorbing effect between the outer wall of the energy storage pipeline and the chamber, the application can not only effectively reduce the probability of damage of the energy storage pipeline, but also reduce the friction between the filling material and the outer wall of the energy storage pipeline and the damage to the outer wall of the energy storage pipeline.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressed air energy storage, in particular to a preparation process of an energy-absorbing and friction-reducing filling material for a buried pipe type abandoned mine compressed air energy storage system. BACKGROUND

[0002] The information disclosed in this Background section is only for the purpose of increasing an understanding of the general background of the application and does not necessarily constitute an acknowledgement or a suggestion that this information forms the prior art already known to a person of ordinary skill in the art.

[0003] Compressed air energy storage (CAES) is a kind of energy storage technology that converts excess electricity during off-peak hours into compressed air for storage, and releases the compressed air to drive a turbine to generate electricity during peak hours, so as to achieve full utilization of electricity and reduce waste. It is a very promising new energy storage technology. This energy storage technology has the advantages of large storage capacity, suitable for long-term energy storage, suitable for large-scale application, and no pollutant emission. At the same time, this energy storage technology also has the problem of high construction cost. The professional equipment and materials required for this technology need a large amount of capital investment, especially the underground cavern for storing compressed air energy storage pipelines, which requires complex engineering design and construction to realize.

[0004] Using abandoned mine tunnels as storage sites for compressed air energy storage pipelines not only can significantly reduce construction costs, but also can realize high-value resource utilization of abandoned mine tunnels. However, the present inventors have found that after the compressed air energy storage pipeline is laid in the abandoned mine tunnel, there is a risk that the tunnel rock will fall or even collapse due to external factors, mine structure factors, etc., which will cause damage to the energy storage pipeline. How to prevent this problem from happening is crucial to ensure the safety and normal operation of the energy storage pipeline. SUMMARY

[0005] In view of the above problems, the present application provides a preparation process of an energy-absorbing and friction-reducing filling material for a buried pipe type abandoned mine compressed air energy storage system. The present application fills a material layer with energy-absorbing function between the outer wall of the energy storage pipeline and the cavern, which not only can effectively reduce the probability of damage to the energy storage pipeline, but also can reduce the friction between the filling material and the outer wall of the energy storage pipeline, which is helpful to reduce the damage to the outer wall of the energy storage pipeline. Specifically, the technical scheme of the present application is as follows.

[0006] The preparation process of the energy-absorbing and friction-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system comprises the following steps:

[0007] (1) Graphitizing coal gangue in an atmosphere isolated from air to graphitize organic matter in the coal gangue, and then cooling to room temperature, crushing to obtain graphitized coal gangue particles, which are ready for use.

[0008] (2) Adding sodium stearate and graphite powder into hot water, stirring until the sodium stearate is dissolved, then adding the graphitized coal gangue particles into the obtained liquid phase and performing ultrasonic treatment. After completion, evaporating water in the reaction system to obtain pretreated coal gangue particles, which are ready for use.

[0009] (3) Mixing the pretreated coal gangue particles with tetraethoxysilane and performing ultrasonic treatment, then separating the particles and placing them in saturated lime water for heating and keeping warm. After completion, separating the particles and drying to obtain self-lubricating and wear-reducing coal gangue particles.

[0010] (4) Mixing the self-lubricating and wear-reducing coal gangue particles with rubber particles uniformly to obtain the filling material.

[0011] Further, in step (1), the particle size of the coal gangue particles is distributed between 8-20 mm. Preferably, the content of organic matter in the coal gangue is not less than 15%.

[0012] Further, in step (1), the graphitization temperature is 1850-2000℃, and the time is 5-7 hours. Optionally, the atmosphere includes any one of nitrogen, argon and the like.

[0013] Further, in step (2), the temperature of the hot water is 60-90℃, so as to facilitate the full dissolution of the sodium stearate.

[0014] Further, in step (2), the sodium stearate in the liquid phase is in a saturated state, and the content of the graphite powder is 7-10 g / L. Optionally, the fineness of the graphite powder is 500-800 mesh.

[0015] Further, in step (2), the solid-liquid ratio of the graphitized coal gangue particles to the liquid phase is 1 g:30-50 ml.

[0016] Further, in step (2), the ultrasonic treatment time is 40-60 min, and the ultrasonic power is 200-300 W. Optionally, the evaporation temperature in step (2) is 100-130℃.

[0017] Further, in step (3), the solid-liquid ratio of the pretreated coal gangue particles to tetraethoxysilane is 1 g:5-10 ml.

[0018] Further, in step (3), the ultrasonic treatment time is 30-40 min, and the ultrasonic power is 200-300 W.

[0019] Further, in step (3), the solid-liquid ratio of the pre-treated coal gangue particles to saturated lime water is 1g: 40-50ml.

[0020] Further, in step (3), the heating temperature is 45-60℃, and the holding time is 8-12 hours.

[0021] Further, in step (4), the mass ratio of the self-lubricating and wear-reducing coal gangue particles to rubber particles is 3.2-4:1. Optionally, the particle size distribution of the rubber particles is between 2-5mm.

[0022] Compared with the prior art, the present application has at least the following beneficial technical effects:

[0023] The present application can not only effectively prevent the energy storage pipeline from being damaged, but also reduce the friction between the outer wall of the energy storage pipeline and the material layer during the expansion and contraction of the energy storage pipeline, thereby reducing the damage to the outer wall of the energy storage pipeline. For this purpose, the present application uses coal gangue, a large amount of industrial solid waste, as raw material and carries out graphitization treatment, thereby converting the coal gangue into graphite components with good friction reduction effect by taking advantage of the fact that the coal gangue contains a large amount of organic matter. At the same time, the elements such as silicon, magnesium, calcium and iron contained in the coal gangue are used as catalysts to reduce the temperature of graphitization and promote the formation of graphite, realizing the resource utilization of the coal gangue. Further, a large number of pores are distributed in the coal gangue after graphitization, which easily leads to a decrease in the compression resistance. Therefore, the present application loads sodium stearate and graphite in the coal gangue after graphitization and then loads tetraethoxysilane, which is reacted with saturated lime water. On the one hand, the sodium stearate reacts with calcium hydroxide to form calcium stearate distributed in the coal gangue, further improving the friction reduction effect of the coal gangue. On the other hand, the active nano-silicon dioxide formed by the hydrolysis of the tetraethoxysilane in the alkaline saturated lime water reacts with calcium hydroxide to form calcium silicate hydrate, which not only helps to improve the compression resistance of the coal gangue, but also helps to anchor the graphite and calcium stearate on the coal gangue, reducing the falling off of them during use. In addition, since the graphite in the coal gangue particles is converted in situ by the organic matter therein, the graphite component is distributed from the inside to the outside of the coal gangue, so that the whole coal gangue has a friction reduction effect, thereby preventing the problem that the new surface of the broken coal gangue particles has a significantly reduced friction reduction effect due to the absence of the late-loaded sodium stearate and graphite. The self-lubricating and friction-reducing coal gangue particles obtained by the above treatment are compounded with rubber particles to form a filling material, which is filled between the outer wall of the compressed air energy storage pipeline and the cavern. After the rock blocks fall or even collapse in the cavern, the filling material can absorb and reduce the impact force in coordination with the rubber particles, and the impact force can be more evenly dispersed on the pipeline outer wall, avoiding stress concentration and reducing damage to the pipeline. At the same time, when the pipeline expands or contracts during the charging and discharging process, the friction between the pipeline outer wall and the filling material is smaller, thereby reducing the damage of the coal gangue particles to the pipeline outer wall, especially for the pipeline with a corrosion-resistant coating, which helps to reduce the damage of the coating and improve the service life of the pipeline. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings, which form a part of the present application, are used to provide a further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve the purpose of explaining the present application, and do not constitute an improper limitation of the present application.

[0025] Figure 1 Sample graph of the graphitized coal gangue particles prepared for the following Example 1.

[0026] Figure 2 Sample picture of the filling material prepared for the following Example 1. DETAILED DESCRIPTION

[0027] The application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the application and not used to limit the scope of the application. The experimental methods in the following examples, if not otherwise specified, are generally carried out according to the conventional conditions or according to the conditions suggested by the manufacturers.

[0028] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those commonly understood by one of ordinary skill in the art. The reagents or raw materials used in the present application can be purchased through conventional routes. Unless otherwise specified, the reagents or raw materials used in the present application are used according to the conventional methods in the art or according to the product instructions. In addition, any method and material similar or equivalent to those described can be applied to the methods of the present application. The technical solutions of the present application are further described in conjunction with the drawings and specific examples in the specification.

[0029] Example 1

[0030] The preparation process of the filling material for the buried pipe type waste mine pressure gas energy storage system to absorb energy and reduce friction includes the following steps:

[0031] (1) Put the coal gangue blocks (organic matter content of 18.26 wt.%) into a heating furnace, and heat to 2000℃ at a heating rate of 20℃ / min in a nitrogen atmosphere, and then keep for 6 hours. After completion, continue to cool to room temperature in a nitrogen atmosphere, crush the product and sieve to obtain graphitized coal gangue particles with a particle size distribution of 8-15 mm, as shown in Figure 1 .

[0032] (2) Add sodium stearate to hot water at 80℃ and stir until the sodium stearate is fully dissolved to form a saturated solution, then add 600 mesh graphite powder at a ratio of 7.5 g / L and stir uniformly. Then add the graphitized coal gangue particles to the obtained liquid phase (solid-liquid ratio of the two = 1 g:40 ml), and ultrasonic treat for 60 min (ultrasonic power of 200 W), and keep the system temperature not lower than 80℃ during the above process. After completion, heat the reaction system to 110℃ and keep to evaporate the water in it to dryness, to obtain pretreated coal gangue particles.

[0033] (3) The pretreated coal gangue particles are mixed with tetraethoxysilane at a ratio of 1 g:7 ml, and then ultrasonic treatment is performed for 30 min (ultrasonic power is 250 W). Then the pretreated coal gangue particles are separated, mixed with saturated lime water at a ratio of 1 g:45 ml, and then heated to 55°C for 10 hours. After completion, the particles are filtered and dried for 24 hours to obtain self-lubricating and wear-reducing coal gangue particles.

[0034] (4) The self-lubricating and wear-reducing coal gangue particles are mixed with particles made of waste rubber and having a particle size distribution of 2-5 mm at a mass ratio of 3.6:1 to obtain a filling material, as shown in Figure 2

[0035] Performance test: (1) The crushing value of the self-lubricating and wear-reducing coal gangue particles prepared in this embodiment is tested according to the "Standard for Quality and Test Methods of Sand and Stone for Ordinary Concrete" (JGJ52-2006) to measure the compressive strength. (2) The self-lubricating and wear-reducing coal gangue particles prepared in this embodiment are loaded into a container and compacted to form a flat upper surface that is higher than the container. Then a steel plate is placed on the upper surface, and a weight is placed on the steel plate to apply a normal pressure. The combined normal pressure of the steel plate and the weight is denoted as G. Then a tension meter is used to horizontally pull the steel plate carrying the weight, and the tension F at this time is recorded. Then the friction coefficient μ1=F / G is calculated to measure the wear-reducing ability of the self-lubricating and wear-reducing coal gangue particles. (3) The self-lubricating and wear-reducing coal gangue particles prepared in this embodiment are crushed and passed through a sieve with a pore size of 5 mm. Then the friction coefficient μ2 of the obtained particles is tested using the above method to measure the wear-reducing ability of the self-lubricating and wear-reducing coal gangue particles after damage. The test results are shown in the following table:

[0036] .

[0037] Example 2

[0038] The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type waste mine pressure gas energy storage system includes the following steps:

[0039] (1) The coal gangue blocks (organic matter content is 15.07 wt.%) are placed in a heating furnace and heated to 1600°C at a heating rate of 20°C / min in a nitrogen atmosphere, and then kept for 5 hours. After completion, the product is crushed and sieved to obtain graphitized coal gangue particles with a particle size distribution of 10-20 mm.

[0040] ​(2)Stir sodium stearate into hot water at 90°C until the sodium stearate is fully dissolved to form a saturated solution, then add 800-mesh graphite powder at a ratio of 7 g / L and stir until uniform. Then add the graphitized coal gangue particles to the resulting liquid phase (solid-liquid ratio = 1 g: 50 ml), and ultrasonically treat for 55 min (ultrasonic power 300 W), then stand for 20 min, maintaining the system temperature at no less than 90°C during the above process. After completion, heat the reaction system to 130°C and maintain the temperature to evaporate the water therein to obtain pretreated coal gangue particles.

[0041] (3) Mix the pretreated coal gangue particles with tetraethoxysilane at a ratio of 1 g: 10 ml, and ultrasonically treat for 40 min (ultrasonic power 200 W), then separate the pretreated coal gangue particles, mix them with saturated lime water at a ratio of 1 g: 50 ml, then heat to 60°C and maintain the temperature for 8 hours. After completion, filter out the particles and air dry for 24 hours to obtain self-lubricating and wear-reducing coal gangue particles.

[0042] (4) Mix the self-lubricating and wear-reducing coal gangue particles with particles of waste rubber having a particle size distribution of 2-5 mm at a mass ratio of 4:1 to obtain a filling material.

[0043] Performance test: The crushing value and friction coefficients μ1 and μ2 of the self-lubricating and wear-reducing coal gangue particles prepared in this example were tested using the same method as in Example 1 above. The test results are shown in the table below:

[0044] .

[0045] Example 3

[0046] The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type waste mine pressure gas energy storage system includes the following steps:

[0047] (1) Place coal gangue blocks (organic matter content 21.19 wt.%) in a heating furnace, and heat to 1850°C at a heating rate of 20°C / min in a nitrogen atmosphere, then maintain the temperature for 7 hours. After completion, continue to cool to room temperature in a nitrogen atmosphere, crush the product, and sieve to obtain graphitized coal gangue particles having a particle size distribution of 8-15 mm.

[0048] (2)Stearic acid sodium is added to hot water at 60°C and stirred until the stearic acid sodium is fully dissolved to form a saturated solution, then 500 mesh graphite powder is added in a proportion of 10 g / L and stirred uniformly. Then the graphitized coal gangue particles are added in the obtained liquid phase (solid-liquid ratio = 1 g:30 ml), and ultrasonic treatment is performed for 40 min (ultrasonic power is 300 W), and the system temperature is kept not lower than 60°C during the above process. After completion, the reaction system is heated to 90°C and kept to evaporate the water therein, to obtain pretreated coal gangue particles.

[0049] (3) The pretreated coal gangue particles are mixed with tetraethoxysilane at a ratio of 1 g:5 ml, and then ultrasonic treatment is performed for 35 min (ultrasonic power is 300 W), then the pretreated coal gangue particles are separated out, mixed with saturated lime water at a ratio of 1 g:40 ml, and then heated to 45°C and kept for 12 hours. After completion, the particles are filtered out and dried for 20 hours, to obtain self-lubricating and wear-reducing coal gangue particles.

[0050] (4) The self-lubricating and wear-reducing coal gangue particles are mixed with the particles made of waste rubber and having a particle size distribution of 2-5 mm at a mass ratio of 3.2:1, to obtain a filling material.

[0051] Performance test: The crushing value and friction coefficients μ1 and μ2 of the self-lubricating and wear-reducing coal gangue particles prepared in this embodiment are tested by the same method as in the above embodiment 1. The test results are shown in the following table:

[0052] 。

[0053] Example 4

[0054] The preparation process of the buried pipe type waste mine gas pressure energy storage system energy absorption and wear reduction filling material includes the following steps:

[0055] (1) Stearic acid sodium is added to hot water at 80°C and stirred until the stearic acid sodium is fully dissolved to form a saturated solution, then 600 mesh graphite powder is added in a proportion of 7.5 g / L and stirred uniformly. Then the coal gangue particles having a particle size distribution of 8-15 mm (organic matter content is 18.26 wt.%) are added in the obtained liquid phase at a solid-liquid ratio of 1 g:40 ml, and ultrasonic treatment is performed for 60 min (ultrasonic power is 200 W), and the system temperature is kept not lower than 80°C during the above process. After completion, the reaction system is heated to 110°C and kept to evaporate the water therein, to obtain pretreated coal gangue particles.

[0056] (2) The pretreated coal gangue particles are mixed with tetraethoxysilane at a ratio of 1 g: 7 ml, and then ultrasonic treatment is performed for 30 min (ultrasonic power is 250 W). Then the pretreated coal gangue particles are separated, mixed with saturated lime water at a ratio of 1 g: 45 ml, and then heated to 55°C for 10 hours. After completion, the particles are filtered and dried for 24 hours to obtain self-lubricating and wear-reducing coal gangue particles.

[0057] (3) The self-lubricating and wear-reducing coal gangue particles are mixed with particles made of waste rubber with a particle size distribution of 2-5 mm at a mass ratio of 3.6:1 to obtain a filling material.

[0058] Performance test: The crushing value and friction coefficients μ1 and μ2 of the self-lubricating and wear-reducing coal gangue particles prepared in this example are tested by the same method as in Example 1 above. The test results are shown in the following table:

[0059] 。

[0060] Example 5

[0061] The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine pressure gas energy storage system includes the following steps:

[0062] (1) The coal gangue block (organic matter content is 21.19 wt.%) is placed in a heating furnace and heated to 1850°C at a heating rate of 20°C / min in a nitrogen atmosphere, and then kept for 7 hours. After completion, it is continuously cooled to room temperature in a nitrogen atmosphere, and the product is crushed and sieved to obtain graphitized coal gangue particles with a particle size distribution of 8-15 mm.

[0063] (2) 500 mesh graphite powder is added to hot water at 60°C at a ratio of 10 g / L and stirred uniformly. Then the graphitized coal gangue particles are added to the obtained liquid phase (solid-liquid ratio = 1 g: 30 ml), and ultrasonic treatment is performed for 40 min (ultrasonic power is 300 W). The temperature of the system is maintained at not less than 60°C during the above process. After completion, the reaction system is heated to 90°C and kept for 12 hours to evaporate the water in it, and pretreated coal gangue particles are obtained.

[0064] (3) The pretreated coal gangue particles are mixed with tetraethoxysilane at a ratio of 1 g: 5 ml, and then ultrasonic treatment is performed for 35 min (ultrasonic power is 300 W). Then the pretreated coal gangue particles are separated, mixed with saturated lime water at a ratio of 1 g: 40 ml, and then heated to 45°C for 12 hours. After completion, the particles are filtered and dried for 20 hours to obtain self-lubricating and wear-reducing coal gangue particles.

[0065] (4) The self-lubricating and wear-reducing coal gangue particles are mixed with the particle materials made of waste rubber and having a particle size distribution of 2-5 mm at a mass ratio of 3.2:1 to obtain the filling material.

[0066] Performance test: The crushing value and the friction coefficients μ1 and μ2 of the self-lubricating and wear-reducing coal gangue particles prepared in this example are tested by using the same method as that in Example 1 above. The test results are shown in the following table.

[0067] 。

[0068] Example 6

[0069] The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type waste mine gas pressure energy storage system includes the following steps:

[0070] (1) The coal gangue block (organic matter content of 15.07 wt.%) is placed in a heating furnace and heated to 1600°C at a heating rate of 20°C / min in a nitrogen atmosphere, and then kept for 5 hours. After completion, it is continuously cooled to room temperature in a nitrogen atmosphere, and the product is crushed and sieved to obtain graphitized coal gangue particles with a particle size distribution of 10-20 mm.

[0071] (2) Sodium stearate is added to hot water at 90°C and stirred until the sodium stearate is fully dissolved to form a saturated solution, and then 800 mesh graphite powder is added at a proportion of 7 g / L and stirred uniformly. Then the graphitized coal gangue particles are added to the obtained liquid phase (solid-liquid ratio = 1 g: 50 ml), and ultrasonic treatment is performed for 55 min (ultrasonic power is 300 W), and then it is left to stand for 20 min. The system temperature is kept above 90°C during the above process. After completion, the reaction system is heated to 130°C and kept for a while to evaporate the water in it to obtain pretreated coal gangue particles.

[0072] (3) The pretreated coal gangue particles are mixed with tetraethoxysilane at a ratio of 1 g: 10 ml and then ultrasonic treatment is performed for 40 min (ultrasonic power is 200 W), and then the pretreated coal gangue particles are separated and mixed with water at a ratio of 1 g: 50 ml, and then heated to 60°C and kept for 8 hours. After completion, the particles are filtered and dried for 24 hours to obtain self-lubricating and wear-reducing coal gangue particles.

[0073] (4) The self-lubricating and wear-reducing coal gangue particles are mixed with the particle materials made of waste rubber and having a particle size distribution of 2-5 mm at a mass ratio of 4:1 to obtain the filling material.

[0074] Performance test: The crushing value and the friction coefficients μ1 and μ2 of the self-lubricating and wear-reducing coal gangue particles prepared in this example are tested by using the same method as that in Example 1 above. The test results are shown in the following table.

[0075] 。

[0076] Example 7

[0077] The preparation process of the filling material for the energy absorption and friction reduction of the buried pipe type waste mine pressure gas energy storage system includes the following steps:

[0078] (1) Put the coal gangue block (organic matter content is 18.26wt.%) into a heating furnace, and heat to 2000℃ at a heating rate of 20℃ / min in a nitrogen atmosphere, and then keep for 6 hours. After completion, continue to cool to room temperature in a nitrogen atmosphere, crush the product and sieve to obtain graphitized coal gangue particles with a particle size distribution of 8-15mm.

[0079] (2) Add sodium stearate to hot water at 80℃ and stir until the sodium stearate is fully dissolved to form a saturated solution. Then add the graphitized coal gangue particles (solid-liquid ratio = 1g:40ml) to the saturated solution, ultrasonic treat for 60min (ultrasonic power is 200W), and keep the system temperature not lower than 80℃ during the above process. After completion, heat the reaction system to 110℃ and keep for a while to evaporate the water in it, to obtain pretreated coal gangue particles.

[0080] (3) Mix the pretreated coal gangue particles with tetraethoxysilane according to 1g:7ml, and ultrasonic treat for 30min (ultrasonic power is 250W), then separate the pretreated coal gangue particles, mix them with saturated lime water according to 1g:45ml, and then heat to 55℃ and keep for 10 hours. After completion, filter out the particles and air dry for 24 hours, to obtain self-lubricating and friction-reducing coal gangue particles.

[0081] (4) Mix the self-lubricating and friction-reducing coal gangue particles with the particles made of waste rubber with a particle size distribution of 2-5mm according to a mass ratio of 3.6:1, to obtain the filling material.

[0082] Performance test: The crushing value and friction coefficients μ1 and μ2 of the self-lubricating and friction-reducing coal gangue particles prepared in this embodiment are tested by the same method as in Example 1 above. The test results are shown in the following table:

[0083] 。

[0084] The above merely describes the preferred embodiments of the present application and is not used to limit the present application, and although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or equivalently replace some technical features thereof. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A preparation process for energy-absorbing and wear-reducing filling materials for buried pipe-type abandoned mine compressed air energy storage systems, characterized in that, Includes the following steps: (1) The organic matter in the coal gangue is graphitized in an air-isolated atmosphere. After the graphitization is completed, it is cooled to room temperature and crushed to obtain graphitized coal gangue particles for later use. (2) Add sodium stearate and graphite powder to hot water and stir until the sodium stearate is fully dissolved. Then add the graphitized coal gangue particles to the resulting liquid phase and perform ultrasonic treatment. After completion, evaporate the water in the reaction system to obtain pretreated coal gangue particles for later use. (3) The pretreated coal gangue particles are mixed with tetraethoxysilane and then ultrasonically treated. The particles are then separated and placed in saturated lime water for heating and heat preservation. After completion, the particles are separated and dried to obtain self-lubricating and friction-reducing coal gangue particles. (4) Mix the self-lubricating and friction-reducing coal gangue particles with rubber particles evenly to obtain the filling material.

2. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, characterized in that, In step (1), the particle size of the coal gangue is distributed between 8 and 20 mm.

3. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, characterized in that, In step (1), the organic matter content in the coal gangue is not less than 15%.

4. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, characterized in that, In step (1), the graphitization temperature is 1850~2000℃ and the time is 5~7 hours.

5. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed gas energy storage system according to claim 1, wherein in step (1), the atmosphere includes any one of nitrogen and argon.

6. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, characterized in that, In step (2), the temperature of the hot water is 60~90℃.

7. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, in step (2), the sodium stearate in the liquid phase is in a saturated state, and the content of the graphite powder is 7~10g / L.

8. In the preparation process of the energy-absorbing and wear-reducing filling material of the buried pipe type abandoned mine compressed air energy storage system according to claim 1, in step (2), the fineness of the graphite powder is 500~800 mesh.

9. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, characterized in that, In step (2), the solid-liquid ratio of the graphitized coal gangue particles to the liquid phase is 1g:30~50ml.

10. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, characterized in that, In step (2), the ultrasonic treatment time is 40~60min and the ultrasonic power is 200~300W.

11. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, wherein in step (2), the evaporation temperature is 100~130℃.

12. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, characterized in that, In step (3), the solid-liquid ratio of the pretreated coal gangue particles to tetraethoxysilane is 1g:5~10ml.

13. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, in step (3), the ultrasonic treatment time is 30~40min and the ultrasonic power is 200~300W.

14. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, characterized in that, In step (3), the solid-liquid ratio of the pretreated coal gangue particles to saturated lime water is 1g:40~50ml.

15. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to claim 1, characterized in that, In step (3), the heating temperature is 45~60℃ and the heat preservation time is 8~12 hours.

16. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to any one of claims 1-9, characterized in that, In step (4), the mass ratio of the self-lubricating and friction-reducing coal gangue particles to the rubber particles is 3.2~4:

1.

17. The preparation process of the energy-absorbing and wear-reducing filling material for the buried pipe type abandoned mine compressed air energy storage system according to any one of claims 1-9, wherein in step (4), the particle size of the rubber particles is distributed between 2 and 5 mm.

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