Cascade recycling method for all components of waste wind power blade, new material and application

Abstract

The invention relates to the technical field of recycling of waste wind power blades, and provides an echelon recycling method of all components of waste wind power blades, a new material and application, and the obtained new material can well balance high strength, high toughness and good thermal insulation performance. The method comprises the following steps that S1, after the retired wind power blade is crushed, screening and impurity removal are conducted, and large-size fragments, medium-size fragments, coarse powder, fine powder I and fine powder II are obtained; s2, preparing materials according to a formula; s3, the large-size fragments and the medium-size fragments are subjected to swelling treatment, and swelled materials are obtained; then adding the coarse powder, the fine powder and a polymer matrix, dispersing and mixing uniformly to obtain a mixture; s4, the mixture is placed in a mold, a curing agent is added, the mixture is mixed to be uniform, and then hot press molding is conducted; and demolding is carried out.

Description

Technical Field

[0001] This invention relates to the field of recycling technology for waste wind turbine blades, specifically to a method, new materials, and applications for the tiered recycling of all components of waste wind turbine blades. Background Technology

[0002] With the rapid development of the global wind power industry, a large number of wind turbine blades have reached the end of their service life, making the disposal of retired wind turbine blades an urgent problem to be solved. Wind turbine blades are mostly made of glass fiber reinforced composite materials or carbon fiber reinforced composite materials. These materials are high in strength and corrosion-resistant, but this also makes traditional disposal methods extremely difficult. Currently, common landfill disposal not only occupies a large amount of land resources, but the materials are also difficult to degrade; incineration releases harmful gases, causing environmental pollution. Regarding recycling, although there have been studies on crushing retired wind turbine blades into single-size or particle-sized products for specific applications, problems remain, including insufficient resource utilization, high energy consumption, and limited product performance. For example, using only large-size fragments as building aggregates fails to utilize the characteristics of other sized products, thus failing to fully realize the potential value of retired wind turbine blades. Furthermore, in actual crushing processes, the initial crushing products exhibit diverse sizes, and utilizing single-size particles results in high energy consumption and low utilization rates. Additionally, existing technologies often require the addition of various fillers and / or additives when preparing new materials, making it impossible to utilize the original additive components of retired wind turbine blades. These include coupling agents (such as KH-550 (aminosilane), KH-570 (methacryloyloxysilane), etc.), reinforcing fillers (such as glass microspheres, calcium carbonate, etc.), talc powder, organic fillers (such as carbon fiber powder, aramid fiber chopped strands, etc.), and / or toughening agents (such as carboxyl-terminated nitrile butadiene rubber (CTBN), epoxy-modified polyurethane, etc.), resulting in complex formulations.

[0003] Therefore, there is an urgent need to develop a method that can make full use of the different sizes and particle sizes of retired wind turbine blades to prepare high-performance, multifunctional new materials, and can utilize existing additives to simplify the required formulation. Summary of the Invention

[0004] To address at least one deficiency in existing technologies, this invention provides a method, new materials, and applications for the tiered recycling of all components of waste wind turbine blades. The method of this invention enables the full recycling of waste wind turbine blades and allows for the preparation of high-performance new materials with a simple formulation system. The resulting new materials achieve a good balance between high strength, high toughness, and good thermal insulation properties.

[0005] To achieve its objective, the present invention provides the following technical solution: This invention provides a method for the tiered recycling of all components of waste wind turbine blades, comprising the following steps: S1. After the decommissioned wind turbine blades are crushed, they are screened and impurities are removed to obtain large fragments with a size of 5-10cm, medium fragments with a size of ≥1cm and <5cm, coarse powder with a size of <1cm and ≥40 mesh, fine powder I with a size of <40 mesh and ≥100 mesh, and fine powder II with a size of <100 mesh. S2. Prepare the ingredients according to the following formula, which includes the following mass percentages of each component: 5-30% of the large-sized fragments and the medium-sized fragments, 10-20% of the coarse powder, 20-40% of the polymer matrix, and the balance being a fine powder mixture composed of fine powder I and fine powder II, wherein the mass percentage of fine powder II in the fine powder mixture is 40%-85%; S3. Weigh each component according to the formula in step S2; The weighed large-sized fragments and medium-sized fragments are swollen with an organic solvent to make the large-sized fragments and medium-sized fragments swell to a volume increase ratio of 80-200%, thus obtaining swollen material; Then, the coarse powder is added to the swollen material and mixed evenly, followed by the fine powder mixture and mixed evenly, and then the polymer matrix is ​​added to disperse and mix the components evenly to obtain a mixture. S4. Place the mixture in a mold, add a curing agent, mix evenly, and then hot press it into shape; then demold it.

[0006] Preferably, in step S2, the mass percentage of the large-sized fragment and the medium-sized fragment is 10-30%.

[0007] Preferably, in step S2, the polymer matrix is ​​epoxy resin; And / or, in step S3, when performing the swelling treatment, the organic solvent is one or more of acetic acid, dichloromethane, benzyl alcohol, dimethylformamide, dimethyl sulfoxide, and ethyl acetate; And / or, in step S4, the curing agent is selected from one or more of amine curing agents and acid anhydride curing agents.

[0008] Preferably, in step S2, the epoxy resin is selected from one or more of bisphenol A type epoxy resin and bisphenol F type epoxy resin; And / or, in step S3, the temperature of the swelling treatment is 80-200℃.

[0009] Preferably, the polymer matrix and the coarse powder are dried to remove moisture before being fed into the feedstock. And / or, in step S3, the dispersion and mixing are carried out using a high-speed mixer at a speed of 500-1000 rpm; And / or, in step S4, the amount of curing agent used is 0.1-0.25 of the mass of the polymer matrix.

[0010] Preferably, in step S4, the temperature of the hot pressing is 120-250°C; And / or, the pressure of the hot pressing is 10-20 MPa; And / or, the hot pressing time is 30 minutes or more.

[0011] More preferably, in step S4, the temperature of the hot pressing is 120-150°C; And / or, the hot pressing time is 30-60 minutes.

[0012] Preferably, after demolding in step S4, post-processing steps including grinding and cutting are also performed.

[0013] Another aspect of the present invention provides a new material prepared from waste wind turbine blades, which is prepared using the method described above.

[0014] The present invention also provides applications of the novel materials described above, in the fields of construction, industrial equipment and / or transportation.

[0015] The technical solution provided by this invention has the following beneficial effects: The method of this invention does not require all waste wind turbine blades to be crushed into smaller sizes (e.g., below 40 mesh). Instead, some large and medium-sized fragments can be retained, significantly reducing the energy consumption required for crushing. This invention utilizes a tiered combination of fragments or powders of various sizes. Through the formulation and process of this invention, new materials can be prepared without the need for complex additives; only a polymer matrix and curing agent are required. This results in new materials with excellent performance, simultaneously achieving superior strength, toughness, and thermal insulation properties. Detailed Implementation

[0016] To facilitate understanding of the present invention, the following description, in conjunction with embodiments, will further illustrate the invention. It should be understood that the following embodiments are merely for a better understanding of the invention and do not imply that the invention is limited to these embodiments.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The term "and / or" may be used herein to include any and all combinations of one or more of the associated listed items.

[0018] This invention provides a method for the tiered recycling of all components of waste wind turbine blades, comprising the following steps: S1. After the decommissioned wind turbine blades are crushed, they are screened and impurities are removed to obtain large fragments with a size of 5-10cm, medium fragments with a size of ≥1cm and <5cm, coarse powder with a size of <1cm and ≥40 mesh, fine powder I with a size of <40 mesh and ≥100 mesh, and fine powder II with a size of <100 mesh. S2. The ingredients are formulated according to the following mass percentages of each component: 5-30% (e.g., 5, 10, 15, 20, 25, 30%) of the large-sized fragments and the medium-sized fragments, 10-20% (e.g., 10, 13, 15, 17, 20%) of the coarse powder, 20-40% (e.g., 20, 25, 30, 35, 40%) of the polymer matrix, and the balance being a fine powder mixture consisting of fine powder I and fine powder II, wherein the mass percentage of fine powder II in the fine powder mixture is 40%-85% (e.g., 40, 50, 60, 70, 80, 85%). S3. Weigh each component according to the formula in step S2; The weighed large-sized fragments and medium-sized fragments are swollen with an organic solvent to increase their volume by 80-200% (e.g., 80, 100, 130, 150, 170, 200%, etc.), resulting in swollen material. Then, the coarse powder is added to the swollen material and mixed evenly, followed by the fine powder mixture and mixed evenly, and then the polymer matrix is ​​added to disperse and mix the components evenly to obtain a mixture. S4. Place the mixture in a mold, add a curing agent, mix evenly, and then hot press it into shape; then demold it.

[0019] This invention does not require all waste wind turbine blades to be crushed into smaller sizes (e.g., below 40 mesh). Instead, it can retain some large and medium-sized fragments, significantly reducing the energy consumption required for crushing. This invention utilizes a tiered combination of fragments or powders of various sizes, combining them according to the above formula. Large and medium-sized fragments are pre-swollen to a volume increase ratio of 80-200%, and then mixed and added in the above-described feeding sequence. Without the need for complex additives, only a polymer matrix and curing agent are required to obtain a new material with excellent performance. This invention fully utilizes the original materials in waste wind turbine blades, leveraging the advantages of products of various sizes and particle sizes. With a simple formula system, a new material with excellent mechanical properties, thermal insulation properties, wear resistance, and environmental protection characteristics is obtained, achieving high-value and comprehensive utilization of retired wind turbine blades, reducing resource waste and environmental pollution, and creating greater economic and social benefits.

[0020] Decommissioned wind turbine blades inherently contain various additives for preparing composite materials; however, existing technologies struggle to fully utilize them. The inventors have discovered that if decommissioned wind turbine blades are only pulverized to a specific particle size, these existing additives are severely damaged and can only be used as fillers, resulting in significant waste. The inventors have found that by crushing decommissioned wind turbine blades into specific multi-gradient sizes, and through swelling and a rational combination of materials from each size gradient, the original resin components and additives can be fully utilized, eliminating the need for additional additives. The fine powder can serve as a seasoning, and the combination of components allows for the preparation of high-performance new materials with a simple formulation.

[0021] In this invention, large and medium-sized fragments provide skeletal structural support, and the medium-sized fragments fill the gaps between larger fragments, enhancing overall stability. Fine powder particles fill micropores, increasing material density and improving interfacial properties with the polymer matrix. Coarse powder fibers are interspersed throughout, enhancing the material's mechanical strength and forming a multi-scale reinforced composite material system. Before feeding, the large and medium-sized fragments are pre-swollen to a volume increase ratio of 80-200%, creating voids that facilitate the entry of smaller materials, dispersion, and full wetting of the polymer matrix. This allows for good and uniform mixing of the components and contributes to obtaining materials with excellent performance.

[0022] In the method of the present invention, in step S3, the large-sized fragments and the medium-sized fragments are first swollen, and then fed and mixed in a specific order. First, the coarse powder is added to the swollen material and mixed evenly, then the fine powder mixture is added and mixed evenly, and then the polymer matrix is ​​added to disperse and mix the components evenly. This feeding and mixing method can achieve uniform mixing of the components without adding additional auxiliary dispersants and helps to obtain materials with excellent performance.

[0023] In this invention, the dimensions of "large fragments" (5-10cm) and "medium fragments" (≥1cm and <5cm) are measured by the length of the fragments; the dimensions of coarse powder, fine powder I, and fine powder II are measured by particle size.

[0024] In step S2, the large-sized fragments and the medium-sized fragments comprise 5-30% of the total material, and can be mixed in any ratio, such as 0.01:1, 0.1:1, 0.5:1, 1:1, 1:0.5, 1:0.1, 1:0.01, etc. Preferably, in step S2, the mass percentage of the large-sized fragments and the medium-sized fragments is 10-30% (e.g., 10, 13, 15, 17, 20, 23, 25, 27, 30%, etc.), which can yield new materials with better performance.

[0025] Preferably, in step S2, the polymer matrix is ​​an epoxy resin; specifically, in step S2, the epoxy resin is selected from one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, etc. Preferably, in step S3, the organic solvent used for the swelling treatment is one or more of acetic acid, dichloromethane, benzyl alcohol, dimethylformamide, dimethyl sulfoxide, and ethyl acetate; preferably, the swelling treatment temperature in step S3 is 80-200℃ (e.g., 80, 100, 130, 150, 170, 200℃, etc.). By using the preferred swelling reagent and swelling conditions, large and medium-sized fragments do not undergo resin degradation or only undergo slight degradation during the swelling process, while simultaneously increasing the fragment volume to the required level.

[0026] Preferably, in step S4, the curing agent is selected from one or more of amine curing agents (e.g., ethylenediamine, diethylenetriamine, etc.) and acid anhydride curing agents (e.g., maleic anhydride, etc.). The specific selection of the curing agent can be determined by those skilled in the art based on the type of epoxy resin and curing conditions. Preferably, in step S4, the amount of the curing agent is 0.1-0.25% of the mass of the polymer matrix.

[0027] In step S1, after the decommissioned wind turbine blades are crushed, they can be screened using equipment such as vibrating screens and impurities can be removed by washing. During washing, high-pressure water guns can be used to remove impurities. After drying, the drying can be carried out in a constant temperature drying oven, with the temperature controlled at 60-80℃ and the time adjusted according to the material characteristics, for example, 2-4 hours.

[0028] Preferably, the polymer matrix and the coarse powder are dried before being fed to remove moisture, thereby avoiding affecting the material properties.

[0029] Preferably, in step S3, the dispersion and mixing are carried out using a high-speed mixer with a mixing speed of 500-1000 rpm and a mixing time of, for example, 10-20 minutes.

[0030] Preferably, in step S4, the temperature of the hot pressing is 120-250℃, more preferably 120-150℃; the pressure of the hot pressing is 10-20MPa; and the hot pressing time is preferably 30 minutes or more, more preferably 30-60 minutes. In step S4, the mixture is cured and formed in the mold, and the polymer matrix is ​​fully impregnated, achieving a tight bond between the components.

[0031] Furthermore, after demolding in step S4, post-processing steps including grinding and cutting are performed to achieve the required dimensional accuracy and surface quality. Grinding can be done using a belt grinder, and cutting can be done using a diamond cutting saw. Dimension processing and surface treatment are performed according to product requirements. Another aspect of the present invention provides a novel material prepared from waste wind turbine blades, which is prepared by the method described above.

[0032] In another aspect, the present invention provides applications of the novel materials described above, in the fields of construction, industrial equipment and / or transportation.

[0033] This invention's method fully utilizes the full-size and full-particle-size products from the crushing of retired wind turbine blades, avoiding resource waste and transforming materials from waste into high-value new materials, thus greatly improving resource utilization. Calculations show that compared to traditional single-size utilization methods, this method can increase blade resource utilization by more than 60%.

[0034] The method of this invention utilizes a novel material prepared from retired wind turbine blades, exhibiting excellent performance, high strength, and high toughness. It demonstrates superior mechanical properties in tensile, compressive, and flexural strengths, making it suitable for manufacturing structural components with high mechanical performance requirements. Tested according to GB / T 1447-2005 "Test Method for Tensile Properties of Fiber Reinforced Plastics," the material's tensile strength can reach over 63 MPa, even reaching 80 MPa, and its flexural strength can reach over 395 MPa, even reaching over 500 MPa. Simultaneously, it possesses good thermal insulation properties, making it applicable to building wall insulation, industrial equipment insulation, and other fields, reducing energy consumption. According to GB / T 10294-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Thermal Insulation Materials - Protective Hot Plate Method," the material's thermal conductivity is as low as 0.05-0.5 W / (m·K). This invention offers significant environmental benefits. The new material primarily utilizes recycled products from decommissioned wind turbine blades, reducing waste emissions and environmental impact. Furthermore, optimized processes further minimize energy consumption and pollutant generation, aligning with green environmental principles. An assessment indicates that producing one ton of this new material can reduce emissions by approximately 1.2 tons of carbon dioxide equivalent. The novel material prepared by this invention has broad application prospects. Its multifunctional characteristics make it suitable for a wide range of applications in fields such as construction, industrial equipment, and parts manufacturing. It can meet the diverse needs of different fields for material performance and create greater market value. For example, in the construction field, it can be used to manufacture exterior wall insulation panels and structural beams; in the industrial equipment field, it can be used to manufacture wear-resistant linings and heat-insulating pipes; and in the transportation field, it can be used to produce automotive parts and high-speed rail interior panels.

[0035] The present invention will be further illustrated by the following embodiments, but it should not be construed as the present invention being limited to these embodiments.

[0036] Where specific experimental steps or conditions are not specified in the examples, the corresponding conventional experimental steps or conditions in this technical field can be followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0037] Test method description: Tensile strength and flexural strength: GB / T 1447-2005 "Test Method for Tensile Properties of Fiber Reinforced Plastics".

[0038] Thermal conductivity: GB / T 10294-2008 "Determination of steady-state thermal resistance and related properties of thermal insulation materials - protective hot plate method".

[0039] In the following examples, the polymer matrix used is bisphenol A type epoxy resin (brand name E-44), and the curing agent used is ethylenediamine.

[0040] Example 1 The following steps are used to prepare new materials from discarded wind turbine blades: S1. After cleaning, the retired wind turbine blades are crushed into products of different sizes and particle sizes by a multi-stage crushing device, then screened and cleaned to remove impurities, and then dried at 80℃ for 3 hours. Obtain large fragments with a size of 5-10cm, medium fragments with a size of ≥1cm and <5cm, coarse powder with a size of <1cm and ≥40 mesh, fine powder I with a size of <40 mesh and ≥100 mesh, and fine powder II with a size of <100 mesh; S2. Prepare materials according to the formula including the following components by mass percentage: Large and medium-sized fragments together account for 10% of the total, with the mass ratio of medium-sized fragments to large fragments being 1:1. Coarse powder 20%; Polymer matrix 30%; The remainder is a mixture of fine powder I and fine powder II, wherein fine powder II accounts for 40% by mass in the fine powder mixture; The coarse powder and polymer matrix are dried to remove moisture before subsequent feeding. S3. Weigh each component according to the formula in step S2; The weighed large and medium-sized fragments were swollen with acetic acid at a swelling temperature of 80°C. After swelling, the large and medium-sized fragments were swollen to a volume increase ratio of 80%, resulting in swollen material. Then, the coarse powder is added to the swollen material and mixed evenly. After that, the fine powder mixture is added and mixed evenly. Then, the polymer matrix is ​​added and dispersed and mixed in a high-speed mixer at a speed of 700 rpm for 15 minutes. After being dispersed evenly, a mixture is obtained. S4. Place the mixture in a mold and add a curing agent. Mix evenly. The amount of curing agent is 0.1 times the mass of the polymer matrix. Then, perform hot pressing molding at a temperature of 150°C, a pressure of 15MPa, and a time of 40min. After hot pressing, demold. After demolding, grind and cut.

[0041] Example 2 The following steps are used to prepare new materials from discarded wind turbine blades: S1. After cleaning, the retired wind turbine blades are crushed into products of different sizes and particle sizes by a multi-stage crushing device, then screened and cleaned to remove impurities, and then dried at 80℃ for 3 hours. Obtain large fragments with a size of 5-10cm, medium fragments with a size of ≥1cm and <5cm, coarse powder with a size of <1cm and ≥40 mesh, fine powder I with a size of <40 mesh and ≥100 mesh, and fine powder II with a size of <100 mesh; S2. Prepare materials according to the formula including the following components by mass percentage: Large and medium-sized fragments together account for 20% of the total, with the mass ratio of medium-sized fragments to large fragments being 5:1. Coarse powder 15%; Polymer matrix 20%; The remainder is a mixture of fine powder I and fine powder II, wherein fine powder II accounts for 60% by mass in the fine powder mixture; The coarse powder and polymer matrix are dried to remove moisture before subsequent feeding. S3. Weigh each component according to the formula in step S2; The weighed large and medium-sized fragments were swollen with acetic acid at a swelling temperature of 150°C. After swelling, the large and medium-sized fragments were swollen to a volume increase ratio of 110%, resulting in swollen material. Then, the coarse powder is added to the swollen material and mixed evenly. After that, the fine powder mixture is added and mixed evenly. Then, the polymer matrix is ​​added and dispersed and mixed in a high-speed mixer at a speed of 900 rpm for 10 minutes. After being dispersed evenly, a mixture is obtained. S4. Place the mixture in a mold and add a curing agent. Mix evenly. The amount of curing agent is 0.2 times the mass of the polymer matrix. Then perform hot pressing molding at a temperature of 180°C, a pressure of 18MPa, and a time of 50min. After hot pressing, demold. After demolding, grind and cut.

[0042] Example 3 The following steps are used to prepare new materials from discarded wind turbine blades: S1. After cleaning, the retired wind turbine blades are crushed into products of different sizes and particle sizes by a multi-stage crushing device, then screened and cleaned to remove impurities, and then dried at 80℃ for 3 hours. Obtain large fragments with a size of 5-10cm, medium fragments with a size of ≥1cm and <5cm, coarse powder with a size of <1cm and ≥40 mesh, fine powder I with a size of <40 mesh and ≥100 mesh, and fine powder II with a size of <100 mesh; S2. Prepare materials according to the formula including the following components by mass percentage: Large and medium-sized fragments together account for 30% of the total, with the mass ratio of medium-sized fragments to large fragments being 1:5. Coarse powder 10%; Polymer matrix 40%; The remainder is a fine powder mixture consisting of fine powder I and fine powder II, wherein fine powder II accounts for 80% by mass in the fine powder mixture; The coarse powder and polymer matrix are dried to remove moisture before subsequent feeding. S3. Weigh each component according to the formula in step S2; The weighed large and medium-sized fragments were swollen with acetic acid at a swelling temperature of 200°C. After swelling, the large and medium-sized fragments were swollen to a volume increase ratio of 200%, resulting in swollen material. Then, the coarse powder is added to the swollen material and mixed evenly. After that, the fine powder mixture is added and mixed evenly. Then, the polymer matrix is ​​added and dispersed and mixed in a high-speed mixer at a speed of 500 rpm for 20 minutes. After being dispersed evenly, a mixture is obtained. S4. Place the mixture in a mold and add a curing agent. Mix evenly. The amount of curing agent is 0.2 times the mass of the polymer matrix. Then, perform hot pressing molding at a temperature of 200°C, a pressure of 17MPa, and a time of 40min. After hot pressing, demold. After demolding, grind and cut.

[0043] Example 4 The procedure is carried out in accordance with Example 1, except that in step S2, the total mass percentage of the large-sized fragments and the medium-sized fragments is 5%.

[0044] Comparative Example 1 The procedure was carried out in accordance with Example 1, except that no coarse powder was added in step S2.

[0045] Comparative Example 2 The procedure is carried out in accordance with Example 1, except that in step S2, no large-sized fragments and medium-sized fragments are added.

[0046] Comparative Example 3 The procedure was carried out in accordance with Example 1, except that in step S3, no swelling treatment was performed on the large and medium-sized fragments.

[0047] Comparative Example 4 The procedure was carried out in accordance with Example 1, except that in step S3, the volume increase rate of large and medium-sized fragments after swelling treatment was 50%.

[0048] Comparative Example 5 The procedure was carried out in accordance with Example 1, except that in step S2, the mass percentage of fine powder II in the fine powder mixture was 20%.

[0049] Comparative Example 6 The same procedure was followed as in Example 1, except that the total proportion of large-sized fragments and medium-sized fragments was 40%.

[0050] The experimental results are shown in Table 1.

[0051] Table 1

[0052] As can be seen from the experimental results, compared with the comparative example, the material prepared by the embodiment of the present invention has better comprehensive performance, and can better balance excellent tensile strength, flexural strength and low thermal conductivity, and has better thermal insulation performance.

[0053] It is readily understood that the above embodiments are merely illustrative examples for clear explanation and do not imply that the invention is limited thereto. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for the tiered recycling and reuse of all components of waste wind turbine blades, characterized in that, Includes the following steps: S1. After the decommissioned wind turbine blades are crushed, they are screened and impurities are removed to obtain large fragments with a size of 5-10cm, medium fragments with a size of ≥1cm and <5cm, coarse powder with a size of <1cm and ≥40 mesh, fine powder I with a size of <40 mesh and ≥100 mesh, and fine powder II with a size of <100 mesh. S2. Prepare the ingredients according to the following formula, which includes the following mass percentages of each component: 5-30% of the large-sized fragments and the medium-sized fragments, 10-20% of the coarse powder, 20-40% of the polymer matrix, and the balance being a fine powder mixture composed of fine powder I and fine powder II, wherein the mass percentage of fine powder II in the fine powder mixture is 40%-85%; S3. Weigh each component according to the formula in step S2; The weighed large-sized fragments and medium-sized fragments are swollen with an organic solvent to make the large-sized fragments and medium-sized fragments swell to a volume increase ratio of 80-200%, thus obtaining swollen material; Then, the coarse powder is added to the swollen material and mixed evenly, followed by the fine powder mixture and mixed evenly, and then the polymer matrix is ​​added to disperse and mix the components evenly to obtain a mixture. S4. Place the mixture in a mold, add a curing agent, mix evenly, and then hot press it into shape; then demold it.

2. The method according to claim 1, characterized in that, In step S2, the mass percentage of the large-sized fragment and the medium-sized fragment is 10-30%.

3. The method according to claim 1, characterized in that, In step S2, the polymer matrix is ​​epoxy resin; And / or, in step S3, when performing the swelling treatment, the organic solvent is one or more of acetic acid, dichloromethane, benzyl alcohol, dimethylformamide, dimethyl sulfoxide, and ethyl acetate; And / or, in step S4, the curing agent is selected from one or more of amine curing agents and acid anhydride curing agents.

4. The method according to claim 3, characterized in that, In step S2, the epoxy resin is selected from one or more of bisphenol A type epoxy resin and bisphenol F type epoxy resin; And / or, in step S3, the temperature of the swelling treatment is 80-200℃.

5. The method according to any one of claims 1-4, characterized in that, Before feeding the polymer matrix and the coarse powder, they are first dried to remove moisture. And / or, in step S3, the dispersion and mixing are carried out using a high-speed mixer at a speed of 500-1000 rpm; And / or, in step S4, the amount of curing agent used is 0.1-0.25 of the mass of the polymer matrix.

6. The method according to any one of claims 1-4, characterized in that, In step S4, the temperature of the hot pressing is 120-250℃; And / or, the pressure of the hot pressing is 10-20 MPa; And / or, the hot pressing time is 30 minutes or more.

7. The method according to claim 6, characterized in that, In step S4, the temperature of the hot pressing is 120-150℃; And / or, the hot pressing time is 30-60 minutes.

8. The method according to any one of claims 1-4, characterized in that, After demolding in step S4, post-processing steps including grinding and cutting are also performed.

9. A novel material prepared using discarded wind turbine blades, characterized in that, It is prepared by the method described in any one of claims 1-8.

10. The application of the new material according to claim 9, characterized in that, The new material is used in the fields of construction, industrial equipment and / or transportation.

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