Wave-absorbing wall material based on waste glass fiber wind turbine blade and preparation method of wave-absorbing wall material

Abstract

The invention relates to the technical field of solid waste recycling and functional building materials, in particular to a wave-absorbing wall material based on a waste glass fiber wind power blade and a preparation method of the wave-absorbing wall material. The wave-absorbing wall material based on the waste glass fiber wind power blade is mainly prepared from the following raw materials in parts by mass: 60-68 parts of waste glass fiber wind power blade granules, 30-35 parts of silicon-aluminum solid wastes, 2-5 parts of a wave-absorbing reinforcing agent and 6-10 parts of water. According to the invention, waste wind power blades and silicon-aluminum solid wastes are used as raw materials, a high-strength porous carbon skeleton structure is formed in the material through a vacuum pugging molding and vacuum sintering process, and meanwhile, a ferrite wave-absorbing reinforcing agent is mixed to form a composite wave-absorbing electromagnetic structure of a carbon aggregate-dielectric loss material and a ferrite particle-magnetic loss material; collaborative optimization of the electromagnetic wave absorption performance and the material mechanical property is achieved, and good ecological value and economic benefits are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste resource utilization and functional building materials, and specifically relates to a wave-absorbing wall material based on discarded glass fiber wind turbine blades and a preparation method thereof. Background Art

[0002] Wind power generation is known for its clean, efficient, and renewable advantages. With the onset of wind turbine retirements, discarded wind turbine blades have become a major solid waste material that urgently needs to be addressed. Wind turbine blades are primarily made of glass fiber / carbon fiber / plant fiber reinforced composite materials, with glass fiber blades accounting for approximately 75% to 85%. Traditionally, discarded glass fiber wind turbine blades have been disposed of primarily through landfill and incineration, resulting in significant resource waste and environmental pollution.

[0003] Silicate-aluminate solid waste refers to industrial and mining solid waste primarily composed of silicon dioxide (SiO2) and aluminum oxide (Al2O3). It originates from a wide range of industries, including mining, metallurgy, building materials, and chemicals. This type of waste has a high silicon and aluminum content, forming a high-strength skeleton structure after calcination, and has potential for application in building materials.

[0004] The modern electromagnetic environment is becoming increasingly complex. Long-term exposure of the human body to electromagnetic radiation may lead to health risks such as leukemia, reproductive system damage, and vision loss. In particular, high-frequency electromagnetic waves (such as 5G millimeter waves) have strong penetrability, and absorbing materials are needed to reduce the exposure intensity in residential areas. At the same time, certain medical equipment (such as high-frequency scalpels and nuclear magnetic resonance imaging devices) are susceptible to external electromagnetic interference, resulting in data distortion or operational failure. Absorbing materials are needed to build shielded rooms to improve their anti-interference capabilities. Existing absorbing materials mostly use metal alloys or carbon-based composite materials, which have problems such as high cost and complex preparation process. Traditional sintered wall materials lack electromagnetic functional design. Therefore, a method for preparing absorbing materials with low raw material cost and simple process is needed. Summary of the Invention

[0005] In view of the problems and shortcomings in the prior art, the present invention aims to provide a low-dimensional mullite phase reinforced silicon carbide-aluminate refractory product and a preparation method thereof.

[0006] In order to achieve the purpose of the present invention, the technical solution adopted by the present invention is as follows:

[0007] The first aspect of the present invention provides a wave-absorbing wall material based on discarded glass fiber wind turbine blades, which is mainly made of the following raw materials in parts by mass: 60 to 68 parts of discarded glass fiber wind turbine blade particles, 30 to 35 parts of silicon-aluminum solid waste, 2 to 5 parts of wave-absorbing enhancer, and 6 to 10 parts of water.

[0008] Preferably, the waste glass fiber wind turbine blade granules are made from retired wind turbine blades through crushing and grinding, and the retired wind turbine blades are composed of 60% to 70% glass fiber and 30% to 40% epoxy resin.

[0009] Preferably, the particle size of the waste glass fiber wind turbine blade particles is ≤0.5 mm.

[0010] Preferably, the wave absorbing enhancer is at least one of ferrite powder, MnO2, nano manganese zinc ferrite powder, barium ferrite powder, carbonyl iron powder, and silicon carbide whiskers.

[0011] More preferably, the wave absorbing enhancer is ferrite powder.

[0012] Preferably, the average particle size of the wave absorbing enhancement agent is ≤1 μm.

[0013] Preferably, the siliceous and aluminous solid waste is at least one of fly ash, steel slag, and tailings sand.

[0014] More preferably, the silicoaluminous solid waste is steel slag.

[0015] More preferably, the tailings sand is quartz tailings sand.

[0016] Preferably, the average particle size of the silicoaluminous solid waste is ≤10 μm.

[0017] A second aspect of the present invention provides a method for preparing an absorbing wall material based on discarded glass fiber wind turbine blades, comprising the following steps:

[0018] S1: adding waste glass fiber wind turbine blade particles, silicon aluminum solid waste, wave absorbing enhancer and water into a blender and mixing them evenly to form a mixture;

[0019] S2: The mixture prepared in step S1 is placed into a mold and pressed to obtain a green body;

[0020] S3: drying the green body obtained in step S2, placing the dried green body in a sintering reactor and evacuating the vacuum, then filling it with protective gas, sintering it under a slightly positive pressure of protective gas, cooling it after sintering, and obtaining a wave-absorbing wall material based on discarded glass fiber wind turbine blades; wherein the sintering temperature is 1100-1300°C, the sintering time is 1-3h, and the vacuum degree during the evacuation of the sintering reactor is 10 -3 ~10 -2 Pa, the slight positive pressure of the protective gas is 0.1~0.15MPa.

[0021] Preferably, in step S3, the heating rate of the sintering treatment is 5-10°C / min.

[0022] Preferably, in step S3, the protective gas is N2; in step S2, the pressing pressure is 5-8 MPa, and the pressing time is 60-90 s.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] (1) This invention uses discarded wind turbine blades and silicon-aluminum solid waste as raw materials. Through vacuum clay forming and vacuum sintering processes, a high-strength, porous carbon skeleton structure is formed inside the material after firing. At the same time, a ferrite absorbing enhancer is mixed to form a composite electromagnetic absorbing structure of carbon aggregate-dielectric loss material and ferrite particles-magnetic loss material, achieving synergistic optimization of electromagnetic wave absorption performance and material mechanical properties. Compared with traditional waste wind turbine blade building material technology, this method retains high mechanical properties while enhancing its electromagnetic function, which will have good ecological value and economic benefits.

[0025] (2) The present invention fully utilizes the organic component epoxy resin in discarded fiberglass wind turbine blades, mixes it with silicon-aluminum solid waste and a wave-absorbing enhancer, and then forms a porous carbon skeleton structure during a vacuum sintering process. Simultaneously, the carbon skeleton acts as a dielectric loss material, which can be combined with ferrite (magnetic loss material) to form a composite wave-absorbing electromagnetic structure, giving the wall material excellent wave-absorbing properties.

[0026] (3) This invention fully utilizes the inorganic glass fiber in discarded fiberglass wind turbine blades, combines it with silicon-aluminum solid waste, and forms a lightweight, high-strength mechanical structure through a vacuum sintering process. The lightweight characteristic is derived from the porous structure created by the carbonization of organic matter and the volatilization of water during the vacuum sintering process. The porous structure also further enhances the wave absorption performance of the wall material.

[0027] (4) Compared with traditional methods of recycling and utilizing discarded wind turbine blades, the present invention provides a new type of building material with both high mechanical properties and electromagnetic functions, expands the resource utilization methods of discarded wind turbine blades, and has good ecological value and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Graphs showing the wave absorption and reflectivity of Examples 1 to 3 and Comparative Example 1;

[0029] Figure 2 This is a graph of the compressive strength of Examples 1 to 3 and Comparative Example 1;

[0030] Figure 3 The absorption reflectivity graphs of Example 1, Examples 4-5, and Comparative Example 2 are shown;

[0031] Figure 4 The compressive strength diagrams of Example 1, Examples 4-5, and Comparative Example 2 are shown;

[0032] Figure 5The absorption reflectivity graphs of Example 1, Examples 6-7, and Comparative Example 3 are shown;

[0033] Figure 6 The compressive strength diagrams of Example 1, Examples 6-7, and Comparative Example 3 are shown;

[0034] Figure 7 The wave absorption reflectivity graphs of Example 1, Examples 8-9, and Comparative Example 4;

[0035] Figure 8 This is a compressive strength diagram of Example 1, Examples 8-9, and Comparative Example 4. DETAILED DESCRIPTION

[0036] The technical solutions of the present invention will be described clearly and completely below in conjunction with specific embodiments. It should be understood that the following embodiments are only partial embodiments of the present invention and are only used to explain the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. It should be understood that other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work are all within the scope of protection of the present invention.

[0037] (1) Investigating the impact of the amount of discarded glass fiber wind turbine blades on the performance of absorbing wall materials

[0038] 1. Sample preparation

[0039] Example 1

[0040] A wave-absorbing wall material based on discarded glass fiber wind turbine blades is made of the following raw materials in parts by mass: 65 parts of discarded glass fiber wind turbine blade granules, 32 parts of silicon-aluminum solid waste, 3 parts of wave-absorbing enhancer, and 8 parts of water; wherein the silicon-aluminum solid waste is fly ash, and the wave-absorbing enhancer is ferrite powder (Fe3O4).

[0041] Among them, the discarded glass fiber wind turbine blades are retired wind turbine blades, which are composed of 70% glass fiber and 30% epoxy resin; the main chemical components of the glass fiber are: SiO261.1%, Al2O315.4%, CaO 9.6%, MgO 5.8%, NaO 3.2%, K2O 2.6%, and others 2.3%; epoxy resin is a high molecular polymer composed of elements such as CH2O3.

[0042] The waste glass fiber wind turbine blade granules are obtained by crushing and grinding retired wind turbine blades to an average particle size of ≤0.5 mm;

[0043] The average particle size of the silicon-alumina solid waste (fly ash) is ≤10 μm;

[0044] The average particle size of the wave absorbing enhancer (ferrite powder) is ≤1 μm.

[0045] The above-mentioned preparation method of the wave-absorbing wall material based on discarded glass fiber wind turbine blades comprises the following specific steps:

[0046] S1: adding waste glass fiber wind turbine blade particles, silicon aluminum solid waste, wave absorbing enhancer and water into a blender and mixing them evenly to form a mixture;

[0047] S2: After the mixture prepared in step S1 is placed into a mold, the mold is maintained at a pressure of 6.5 MPa for 75 seconds to obtain a green body;

[0048] S3: drying the green body obtained in step S2, placing the dried green body in a sintering reactor and evacuating the reactor to remove air and moisture, then filling the reactor with protective gas, and sintering the green body under a slightly positive pressure of N2. After sintering, cooling the green body to obtain a wave-absorbing wall material based on discarded glass fiber wind turbine blades; wherein the sintering temperature is 1200°C, the heating rate is 7°C / min, the sintering time is 2h, and the vacuum degree during the evacuation of the sintering reactor is 5×10 - 3 Pa, N2 slight positive pressure is 0.12MPa.

[0049] Example 2

[0050] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that it is made from the following raw materials in parts by mass: 60 parts of discarded glass fiber wind turbine blade particles, 32 parts of silicon-aluminum solid waste, 3 parts of wave-absorbing enhancer, and 8 parts of water.

[0051] Example 3

[0052] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that it is made from the following raw materials in parts by mass: 68 parts of discarded glass fiber wind turbine blade particles, 32 parts of silicon-aluminum solid waste, 3 parts of wave-absorbing enhancer, and 8 parts of water.

[0053] Comparative Example 1

[0054] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that it is made from the following raw materials in parts by mass: 0 parts of discarded glass fiber wind turbine blade particles, 97 parts of silicon-aluminum solid waste, 3 parts of wave-absorbing enhancer, and 8 parts of water.

[0055] 2. Performance testing

[0056] The absorbing reflectivity of the absorbing wall materials based on discarded glass fiber wind turbine blades prepared in Examples 1 to 3 and Comparative Example 1 was tested by the bow reflection method in GJB2038A-2011 "Test Method for Reflectivity of Radar Absorbing Materials" and the compressive strength was tested by the test method in GB / T13544-2011 "Sintered Porous Bricks and Porous Blocks". The test results are as follows: Figure 1 、 Figure 2 shown.

[0057] Depend on Figure 1 It can be seen that adjusting the amount of discarded glass fiber wind turbine blades in Examples 1 to 3 and Comparative Example 1 has a significant effect on the wave absorption reflectivity of the absorbing wall material. Among them, the amount of discarded glass fiber wind turbine blades in Comparative Example 1 is 0, and fly ash is used to replace it. Its wave absorption reflectivity ranges from 0 to -5dB in the electromagnetic wave range of 2 to 18GHz. The wave absorption reflectivity range of Example 1 is -4 to -10dB, the wave absorption reflectivity range of Example 2 is -2 to -8dB, and the wave absorption reflectivity range of Example 3 is -10 to -13dB. This shows that the more discarded glass fiber wind turbine blades are used, the better the wave absorption and reflection effect of the absorbing wall material. This is because the organic epoxy resin components in the discarded glass fiber wind turbine blades will be carbonized during the vacuum sintering process to form a porous carbon skeleton structure, which can be used as a dielectric loss material to consume the incident electromagnetic waves, and the amount of discarded glass fiber wind turbine blades is proportional to the content of the carbon skeleton structure.

[0058] Depend on Figure 2 As can be seen, the use of fly ash to replace the waste fiberglass wind turbine blades in Comparative Example 1 results in a higher compressive strength. The compressive strength of Comparative Example 1 is 16.8 MPa, while that of Examples 1-3 is 11.9 MPa, 12.1 MPa, and 9.8 MPa, respectively. Among Comparative Example 1 and Examples 1-3, Comparative Example 1, Example 1, and Example 2 meet the MU10 strength requirements specified in GB / T 13544-2011, "Sintered Porous Bricks and Porous Blocks," while Example 3 falls slightly below the MU10 strength requirement. Furthermore, the greater the amount of waste fiberglass wind turbine blades used in Examples 1-3, the lower the compressive strength of the absorbing wall material. This is because the smaller the amount of waste fiberglass wind turbine blades used, the fewer pores within the absorbing wall material, resulting in a denser structure and, consequently, a higher compressive strength.

[0059] (2) Investigating the influence of the type of siliceous raw materials on the performance of absorbing wall materials

[0060] 1. Sample preparation

[0061] Example 4

[0062] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that it is made from the following raw materials in parts by mass: 65 parts of discarded glass fiber wind turbine blade particles, 32 parts of silicon-aluminum solid waste, 3 parts of wave-absorbing enhancer, and 8 parts of water; wherein the silicon-aluminum solid waste is steel slag.

[0063] Example 5

[0064] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that it is made from the following raw materials in parts by mass: 65 parts of discarded glass fiber wind turbine blade particles, 32 parts of siliceous aluminum solid waste, 3 parts of wave-absorbing enhancer, and 8 parts of water; wherein the siliceous aluminum solid waste is quartz tailings sand.

[0065] Comparative Example 2

[0066] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that it is made from the following raw materials in parts by mass: 97 parts of discarded glass fiber wind turbine blade particles, 0 parts of silicon-aluminum solid waste, 3 parts of wave-absorbing enhancer, and 8 parts of water.

[0067] 2. Performance Testing

[0068] The absorbing wall materials based on discarded glass fiber wind turbine blades prepared in Example 1, Examples 4-5, and Comparative Example 2 were tested for their absorbing reflectivity by the bow reflection method in GJB2038A-2011 "Test Method for Reflectivity of Radar Absorbing Materials" and for their compressive strength by the test method described in GB / T 13544-2011 "Sintered Porous Bricks and Porous Blocks". The test results are as follows: Figure 3 、 Figure 4 shown.

[0069] Depend on Figure 3It can be seen that adjusting the type of silicon-aluminum solid waste in Example 1, Examples 4 to 5, and Comparative Example 2 will affect the wave absorption reflectivity of the absorbing wall material. In Comparative Example 2, the silicon-aluminum solid waste is replaced by discarded glass fiber wind turbine blades, that is, no silicon-aluminum solid waste is used, and its wave absorption reflectivity ranges from -13 to -18 dB in the electromagnetic wave range of 2 to 18 GHz. Example 1 is -4 to -10 dB, Example 4 is -7 to -11 dB, and Example 5 is -3 to -9 dB. That is, when steel slag is used as the silicon-aluminum solid waste in Example 4, the wave absorption and reflection effect of the absorbing wall material is better; when quartz tailings sand is used as the silicon-aluminum solid waste in Example 5, the wave absorption and reflection effect is poor. When discarded glass fiber wind turbine blades are used to replace the silicon-aluminum solid waste in Comparative Example 2, the wave absorption and reflection effect is relatively good. This is because steel slag contains ferrite components such as FeO and Fe3O4, which can be used as a magnetic loss material after vacuum sintering. In contrast, quartz tailings contain relatively little ferrite. Furthermore, in Comparative Example 2, when discarded fiberglass wind turbine blades replaced the silicon-aluminum solid waste, the carbon skeleton structure of the absorbing wall material increased after vacuum sintering, and the corresponding absorbing and reflecting effect was improved.

[0070] Depend on Figure 4 As can be seen, in Comparative Example 2, where waste glass fiber wind turbine blades were used to replace the silicon-alumina solid waste, the compressive strength was significantly lower. This is because the larger the proportion of porous carbon skeletons after vacuum sintering, the compressive strength was 5.9 MPa, indicating a significant decrease in mechanical properties. The compressive strengths of Examples 1, 4-5, and 5 were 11.9 MPa, 11.7 MPa, and 11.1 MPa, respectively. All of these met the MU10 strength grade requirements of GB / T 13544-2011, "Sintered Porous Bricks and Porous Blocks." Furthermore, the compressive strength of the absorbing wall material varied with the type of silicon-alumina solid waste, but the difference was not significant. This is because the compressive strength of the absorbing wall material is primarily limited by its internal pore structure. The same amount of waste glass fiber wind turbine blades was used in Examples 1 and 4-5, resulting in similar carbonized pore structures after sintering.

[0071] (3) Investigate the effect of the amount of absorbing enhancer on the performance of absorbing wall materials

[0072] 1. Sample preparation

[0073] Example 6

[0074] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that it is made from the following raw materials in parts by mass: 65 parts of discarded glass fiber wind turbine blade particles, 32 parts of silicon-aluminum solid waste, 2 parts of wave-absorbing enhancer, and 8 parts of water.

[0075] Example 7

[0076] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that it is made from the following raw materials in parts by mass: 65 parts of discarded glass fiber wind turbine blade particles, 32 parts of silicon-aluminum solid waste, 5 parts of wave-absorbing enhancer, and 8 parts of water.

[0077] Comparative Example 3

[0078] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that it is made from the following raw materials in parts by mass: 65 parts of discarded glass fiber wind turbine blade particles, 32 parts of silicon-aluminum solid waste, 0 parts of wave-absorbing enhancer, and 8 parts of water.

[0079] 2. Performance Testing

[0080] The absorbing wall materials based on discarded glass fiber wind turbine blades prepared in Example 1, Example 6-7, and Comparative Example 3 were tested for their absorbing reflectivity by the bow reflection method in GJB2038A-2011 "Test Method for Reflectivity of Radar Absorbing Materials" and their compressive strength by the test method in GB / T 13544-2011 "Sintered Porous Bricks and Porous Blocks". The test results are as follows: Figure 5 、 Figure 6 shown.

[0081] Depend on Figure 5 It can be seen that adjusting the amount of ferrite powder (Fe3O4), the wave absorption enhancer, in Example 1, Examples 6-7, and Comparative Example 3 will affect the wave absorption reflectivity of the wave absorbing wall material. In Comparative Example 3, the amount of ferrite powder (Fe3O4) is 0, and its wave absorption reflectivity ranges from -2 to -9 dB in the electromagnetic wave range of 2 to 18 GHz. Example 1 is -4 to -10 dB, Example 6 is -3 to -9 dB, and Example 7 is -5 to -11 dB. That is, the more ferrite powder (Fe3O4) is used, the better the wave absorption and reflection effect. This is because ferrite powder (Fe3O4) can be used as a magnetic loss material, which can add a microwave absorption loss mechanism to the wave absorbing wall material. The higher its content, the more the wall material intercepts the incident electromagnetic wave and the better the wave absorption performance.

[0082] Depend on Figure 6As can be seen, the compressive strength of Comparative Example 3 is 11.6 MPa, while that of Example 1, Examples 6-7, and Examples 6-7 are 11.9 MPa, 11.8 MPa, and 12.1 MPa, respectively. Comparative Example 3, Example 1, and Examples 6-7 all meet the strength grade MU10 requirements of GB / T 13544-2011, "Sintered Porous Bricks and Porous Blocks." This demonstrates that, on the one hand, ferrite powder (Fe₃O₄) has a minimal effect on the compressive strength of the absorbing wall material, with little change in its compressive strength. On the other hand, increasing the amount of ferrite powder (Fe₃O₄) results in a slight increase in the compressive strength of the absorbing wall material. This is because ferrite powder (Fe₃O₄) forms a stable solid solution with inorganic components such as SiO₂ during the sintering process, providing support.

[0083] (4) Investigate the influence of the heating rate of the sintering process on the performance of the absorbing wall material

[0084] 1. Sample preparation

[0085] Example 8

[0086] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that: in step S3 of the preparation method of the wave-absorbing wall material based on discarded glass fiber wind turbine blades, the heating rate is 5°C / min.

[0087] Example 9

[0088] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that: in step S3 of the preparation method of the wave-absorbing wall material based on discarded glass fiber wind turbine blades, the heating rate is 10°C / min.

[0089] Comparative Example 4

[0090] A wave-absorbing wall material based on discarded glass fiber wind turbine blades, the preparation method of which is basically the same as that of Example 1, except that: in step S3 of the preparation method of the wave-absorbing wall material based on discarded glass fiber wind turbine blades, the heating rate is 2°C / min.

[0091] 2. Performance Testing

[0092] The absorbing wall materials based on discarded glass fiber wind turbine blades prepared in Example 1, Examples 8-9, and Comparative Example 4 were tested for their absorbing reflectivity by the bow reflection method in GJB2038A-2011 "Test Method for Reflectivity of Radar Absorbing Materials" and for their compressive strength by the test method described in GB / T 13544-2011 "Sintered Porous Bricks and Porous Blocks". The test results are as follows: Figure 7 、 Figure 8 shown.

[0093] Depend on Figure 7It can be seen that adjusting the heating rate in Examples 1, Examples 8-9, and Comparative Example 4 significantly affects the absorption and reflectivity of the absorbing wall material. In Comparative Example 4, when the heating rate was 2°C / min, the absorption and reflectivity within the 2-18 GHz electromagnetic wave range varied from -1 to -5 dB. Example 1 was -4 to -10 dB, Example 8 was -3 to -10 dB, and Example 9 was -5 to -11 dB. The wall material in Comparative Example 4 had the worst absorption and reflectivity, while in Examples 1 and Examples 8-9, the absorption and reflectivity gradually improved with increasing heating rate. This is because the heating rate in Comparative Example 4 is relatively low, and the epoxy resin in the discarded glass fiber wind turbine blades is prone to thermal decomposition reaction in the temperature range of 400°C to 500°C during vacuum sintering, and the organic matter is converted into liquid and gas and lost from the wall material, which eventually leads to a significant reduction in the carbon skeleton structure, thereby worsening its wave absorption and reflection effect; the higher the heating rate in Example 1 and Examples 8 to 9, the greater the proportion of carbon skeleton formed by the epoxy resin in the discarded glass fiber wind turbine blades during the vacuum sintering process, and the correspondingly better its wave absorption and reflection effect.

[0094] Depend on Figure 8 As can be seen, the compressive strength of Comparative Example 4 is 4.8 MPa, while that of Example 1, Examples 8-9, and Examples 9-10.7 MPa, respectively, is 11.9 MPa, 12.0 MPa, and 10.7 MPa. All Examples 1 and 8-9 meet the MU10 strength grade requirements of GB / T 13544-2011, "Sintered Porous Bricks and Porous Blocks." However, the compressive strength of Comparative Example 4 falls far short of the MU10 requirement. This is due to the slow heating rate, which causes a large amount of epoxy resin to pyrolyze and vaporize in the 400°C to 500°C temperature range, creating numerous pores within the wall material and reducing its strength. The compressive strengths of Examples 1 and 8 are similar, while the compressive strength of Example 9 decreases slightly. This is because a small amount of gas escapes from the wall material during the vacuum sintering process, leaving defects within the structure. The faster the heating rate, the more defects are left behind during the gas escape process, resulting in a decrease in compressive strength.

[0095] The above describes a preferred embodiment of the present invention, but it should be understood that the invention is not limited to the contents disclosed herein. As long as non-substantial improvements are made using the method concepts and technical solutions of the present invention, or the method concepts and technical solutions of the present invention are applied to other occasions, they are all within the scope of protection of the present invention.

Claims

1. A wave-absorbing wall material based on discarded glass fiber wind turbine blades, characterized in that: The invention is mainly prepared from the following raw materials in parts by mass: 60-68 parts of waste glass fiber wind turbine blade granular materials, 30-35 parts of silicon-aluminum solid waste, 2-5 parts of wave absorbing enhancer and 6-10 parts of water.

2. The wave-absorbing wall material based on discarded glass fiber wind turbine blades according to claim 1 is characterized in that: The waste glass fiber wind turbine blade granules are made from retired wind turbine blades through crushing and grinding. The retired wind turbine blades are composed of 60% to 70% glass fiber and 30% to 40% epoxy resin.

3. The wave-absorbing wall material based on discarded glass fiber wind turbine blades according to claim 1, characterized in that: The wave absorbing enhancer is at least one of ferrite powder, MnO2, nano manganese zinc ferrite powder, barium ferrite powder, carbonyl iron powder, and silicon carbide whiskers.

4. The wave-absorbing wall material based on discarded glass fiber wind turbine blades according to claim 1, characterized in that: The silicon-alumina solid waste is at least one of fly ash, steel slag, and tailings sand.

5. The wave-absorbing wall material based on discarded glass fiber wind turbine blades according to claim 2, characterized in that: The particle size of the waste glass fiber wind turbine blade particles is ≤0.5 mm.

6. The wave-absorbing wall material based on discarded glass fiber wind turbine blades according to claim 3, characterized in that: The particle size of the wave absorbing enhancer is ≤1 μm, and the particle size of the silicon-aluminum solid waste is ≤10 μm.

7. The wave-absorbing wall material based on discarded fiberglass wind turbine blades according to claim 6, characterized in that: The wave absorbing enhancer is ferrite powder, and the silicon-aluminum solid waste is steel slag.

8. The method for preparing the wave-absorbing wall material based on waste glass fiber wind turbine blades according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: adding waste glass fiber wind turbine blade particles, silicon-aluminum solid waste, wave absorbing enhancer and water into a blender and mixing them evenly to form a mixture; S2: The mixture prepared in step S1 is placed into a mold and pressed to obtain a green body; S3: drying the green body obtained in step S2, placing the dried green body in a sintering reactor and evacuating the vacuum, then filling it with protective gas, sintering it under a slightly positive pressure of protective gas, cooling it after sintering, and obtaining a wave-absorbing wall material based on discarded glass fiber wind turbine blades; wherein the sintering temperature is 1100-1300°C, the sintering time is 1-3h, and the vacuum degree during the evacuation of the sintering reactor is 10 -3 ~10 -2 Pa, the slight positive pressure of the protective gas is 0.1~0.15MPa. 9 . The preparation method according to claim 8 , wherein in step S3 , the heating rate of the sintering treatment is 5-10° C. / min.

10. The preparation method according to claim 8, characterized in that In step S3, the protective gas is N2; in step S2, the pressing pressure is 5-8 MPa, and the pressing time is 60-90 s.

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