Recovery method of ultra-high molecular weight polyethylene waste

Abstract

The invention belongs to the technical field of plastic recycling and reusing, and particularly relates to a recycling method of ultra-high molecular weight polyethylene waste. The recycling method of the ultra-high molecular weight polyethylene waste comprises the following steps: S1, pretreating the ultra-high molecular weight polyethylene waste to obtain pretreated polyethylene waste; s2, the pretreated polyethylene waste is subjected to electron beam radiation treatment, and radiation treated polyethylene waste is obtained; s3, mixing the radiation-treated polyethylene waste with a degradation aid, and performing solid-phase treatment to obtain a polyethylene waste crushed material; s4, mixing the polyethylene waste crushed material with an organic solvent, performing high-temperature dissolution treatment, adding an alcohol solvent to separate out polyethylene, performing solid-liquid separation to obtain solid and liquid, and drying the solid into powder to obtain recycled polyethylene powder; the recycling method not only can ensure effective recycling of wastes, but also can realize cyclic utilization of other raw materials.

Description

Technical Field

[0001] This invention belongs to the field of plastic recycling technology, specifically relating to a method for recycling ultra-high molecular weight polyethylene waste. Background Technology

[0002] Ultra-high molecular weight polyethylene (UHMWPE) refers to linear high-density ethylene with a viscosity-average molecular weight greater than 1.5 million. UHMWPE has the same molecular structure as ordinary polyethylene (PE), but its extremely high molecular weight endows UHMWPE with many superior properties that ordinary PE cannot match. Due to its excellent properties, the application fields of UHMWPE are constantly expanding, and its usage is continuously increasing. However, the production, processing, and use of UHMWPE products generate a large amount of waste. Because this material possesses extremely high low-temperature toughness and extremely high melt viscosity, existing crushing, granulation, and recycling processes are insufficient to effectively treat it, resulting in these wastes often only being disposed of through high-temperature pyrolysis or incineration.

[0003] From the perspective of technological innovation, if low-cost UHMWPE waste can be converted back into polyethylene powder and suitable application scenarios can be found, it will overcome a major technical challenge in the recycling of UHMWPE materials.

[0004] Chinese patent (publication number CN117447766A) discloses a method for recycling waste ultra-high molecular weight polyethylene (UHMWPE) and its application in rotomolded packaging boxes. This invention first adds waste UHMWPE and persulfate as a degradation aid to a solid-state chemical reactor for ultrafine pulverization. The main chain is broken down, the entangled structure is unwound, and the molecular weight is reduced through extrusion, shearing, and strong oxidative degradation. Then, it is mixed with an organic solvent at high temperature for dissolution and degradation, further reducing the molecular weight through high-temperature thermo-oxidative decomposition. Finally, an alcohol solvent is added to precipitate the polyethylene, resulting in a polyethylene degradation material with a significantly reduced molecular weight. However, this technology uses persulfate as a degradation aid, which is insoluble in both organic and alcohol solvents. This may lead to residual degradation aid affecting the performance of the recycled polyethylene, and also makes it difficult to recycle other raw materials in the recycling process.

[0005] Therefore, there is an urgent need for a recycling method for ultra-high molecular weight polyethylene waste. By selecting appropriate degradation aids and combining them with other process improvements, we can ensure the effective recycling of waste and realize the recycling of other raw materials. Summary of the Invention

[0006] The purpose of this invention is to provide a method for recycling ultra-high molecular weight polyethylene (UHMWPE) waste. This invention pre-treats the UHMWPE waste, then performs preliminary degradation through electron beam radiation treatment, then mixes it with a degradation aid for solid-phase treatment, and finally mixes it with an organic solvent for high-temperature dissolution treatment. Polyethylene is then precipitated through an alcohol solvent, thereby realizing the recycling of polyethylene powder.

[0007] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for recycling ultra-high molecular weight polyethylene waste, comprising the following steps: Step S1: Pre-treat the ultra-high molecular weight polyethylene waste to obtain pre-treated polyethylene waste; Step S2: The pretreated polyethylene waste is subjected to electron beam irradiation to obtain irradiated polyethylene waste; Step S3: Mix the radiation-treated polyethylene waste and the degradation aid, and then perform solid-phase treatment to obtain polyethylene waste pulverized material; Step S4: Mix the polyethylene waste pulverized material with an organic solvent and perform high-temperature dissolution treatment. Then add an alcohol solvent to precipitate polyethylene. Separate the solid and liquid to obtain a solid and a liquid. Dry the solid into powder to obtain recycled polyethylene powder.

[0008] As a preferred embodiment, the pretreatment conditions in step S1 are as follows: place the sample in a nitrogen atmosphere and pretreat at 110~120℃ for 60~80 minutes.

[0009] As a preferred embodiment, the pretreatment temperature described in this invention can be 110℃, 112℃, 114℃, 116℃, 118℃, or 120℃, etc.

[0010] As a preferred embodiment, the pretreatment time in this invention can be 60 min, 65 min, 70 min, 75 min, or 80 min, etc.

[0011] This invention collects and preliminarily cleans ultra-high molecular weight polyethylene waste through pretreatment, removing surface impurities, moisture, and other non-polyethylene components, which is beneficial to subsequent recycling processes.

[0012] As a preferred embodiment, the conditions for electron beam radiation treatment in step S2 are as follows: using a 1.5MeV electron accelerator, an electron beam energy of 1.2MeV, a beam current of 2mA, and an irradiation dose of 80~100kGy.

[0013] As a preferred embodiment, the irradiation dose of the electron beam radiation treatment described in this invention can be 80 kGy, 85 kGy, 90 kGy, 95 kGy, or 100 kGy, etc.

[0014] Electron beam oxidation utilizes high-energy electron beams to bombard ultra-high molecular weight polyethylene (UHMWPE) waste, triggering a series of complex physical and chemical reactions. By adjusting the appropriate electron beam energy and dosage, the initial degradation of UHMWPE can be achieved, which is beneficial for subsequent recycling.

[0015] As a preferred embodiment, by weight, in step S3, the amount of polyethylene waste subjected to radiation treatment is 50-60 parts, and the amount of degradation aid is 4-6 parts; in step S4, the amount of organic solvent is 500-600 parts, and the amount of alcohol solvent is 500-600 parts.

[0016] As a preferred embodiment, the weight fractions of the polyethylene waste subjected to radiation treatment in this invention can be 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, or 60 parts, etc.

[0017] As a preferred embodiment, the weight parts of the degradation aid described in this invention can be 4 parts, 4.5 parts, 5 parts, 5.5 parts, or 6 parts, etc.

[0018] As a preferred embodiment, the organic solvent in this invention can be in the following weight proportions: 500 parts, 520 parts, 540 parts, 560 parts, 580 parts, or 600 parts, etc.

[0019] As a preferred embodiment, the weight parts of the alcohol solvent in this invention can be 500 parts, 520 parts, 540 parts, 560 parts, 580 parts, or 600 parts, etc.

[0020] As a preferred embodiment, the degradation aids in step S3 are manganese acetylacetone and ferric stearate.

[0021] As a preferred embodiment, the mass ratio of manganese acetylacetone and ferric stearate in the degradation aid is (1~2):1; preferably, the mass ratio can be 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1 or 2:1.

[0022] This invention uses manganese acetylacetonate and ferric stearate as compound degradation aids. Manganese acetylacetonate has good thermal stability and processing compatibility, remaining stable at temperatures below 160°C. It can be blended with ultra-high molecular weight polyethylene waste during the solid-phase treatment stage. Compared with inorganic manganese salts, its organic ligand structure makes it more compatible with non-polar polymers and reduces agglomeration. Its good dispersibility ensures that the degradation catalytic sites are evenly distributed throughout the material. The long-chain alkyl groups in ferric stearate molecules are similar to the non-polar molecular chain structure of ultra-high molecular weight polyethylene. Through hydrophobic interactions, it can be evenly dispersed in the polymer matrix. At the same time, ferric stearate has good thermal stability, which can meet the high-temperature processing requirements (150-170°C) of solid-phase treatment, maintaining stable activity over a long processing time.

[0023] As a preferred embodiment, the grinding pressure of the solid phase treatment is 10~15MPa, the rotation speed is 50~60r / min, and the circulating cooling water temperature is 40~50℃.

[0024] As a preferred embodiment, the grinding pressure for solid phase treatment in this invention can be 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, or 15 MPa, etc.

[0025] As a preferred embodiment, the rotational speed of the solid-phase treatment in this invention can be 50 r / min, 52 r / min, 54 r / min, 56 r / min, 58 r / min or 60 r / min, etc.

[0026] As a preferred embodiment, the circulating cooling water temperature in this invention can be 40℃, 42℃, 44℃, 46℃, 48℃, or 50℃, etc.

[0027] This invention achieves effective pulverization of radiation-treated polyethylene waste through solid-phase treatment, thereby obtaining polyethylene waste pulverized material, which can ensure the smooth progress of subsequent high-temperature melting treatment and improve the recycling efficiency of polyethylene powder.

[0028] As a preferred embodiment, the organic solvent in step S4 is benzene; As a preferred embodiment, the alcohol solvent in step S4 is anhydrous ethanol.

[0029] This invention uses benzene as an organic solvent. Benzene can dissolve ultra-high molecular weight polyethylene waste under high temperature conditions, and polyethylene powder can be precipitated by adding anhydrous ethanol. At the same time, the degradation aids manganese acetylacetonate and ferric stearate are insoluble in anhydrous ethanol, while manganese acetylacetonate is soluble in benzene at room temperature and ferric stearate is soluble in benzene under heating conditions. Therefore, the raw materials can be recycled by taking advantage of the difference in solubility of the degradation aids in different solvents.

[0030] As a preferred embodiment, the temperature of the high-temperature melting treatment is 140~150℃; more preferably, the high-temperature melting treatment temperature can be 140℃, 142℃, 144℃, 146℃, 148℃ or 150℃.

[0031] This invention controls the temperature of the high-temperature dissolution process within a suitable range, ensuring that the pulverized polyethylene waste can dissolve in the organic solvent. This avoids both the deterioration of the activity of the degradation aid due to high temperature and the poor solubility due to too low a temperature, thereby achieving a good polyethylene powder recycling effect.

[0032] As a preferred embodiment, the liquid obtained from the solid-liquid separation in step S4 is recycled. The recycling process involves: first, distilling the liquid from the solid-liquid separation to obtain a mixture of recovered ethanol and solvent; then, cooling the solvent mixture to 10-20°C to precipitate and recover iron stearate; and finally, removing the solvent by rotary evaporation to obtain recovered manganese acetylacetone.

[0033] As a preferred embodiment, the cooling temperature can be 10℃, 12℃, 14℃, 16℃, 18℃, or 20℃, etc.

[0034] As a preferred embodiment, the recycled polyethylene powder has a sieve residue of ≤1% and a density of 0.93~0.96 g / cm³. 3 The apparent density is 0.2~0.4 g / cm³. 3 Volatile matter ≤0.5%.

[0035] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. This invention first pre-degrades ultra-high molecular weight polyethylene waste through pretreatment and electron beam radiation oxidation treatment, then performs solid-phase treatment with a compound degradation aid of manganese acetylacetone and ferric stearate, followed by high-temperature dissolution treatment using the organic solvent benzene, and then adds an alcohol solvent to precipitate polyethylene, achieving efficient recovery of polyethylene powder. The recovered polyethylene powder has good performance, with indicators such as sieve residue, volatile matter, and ash content at optimal levels. Furthermore, it can achieve the recycling of other raw materials through process improvement.

[0036] 2. The electron beam radiation oxidation of the present invention utilizes a high-energy electron beam to bombard ultra-high molecular weight polyethylene waste, triggering a series of complex physical and chemical reactions. By adjusting the appropriate electron beam energy and dosage, the initial degradation of ultra-high molecular weight polyethylene can be achieved, which is beneficial for subsequent recycling.

[0037] 3. The manganese acetylacetonate of the present invention has a stronger oxidizing ability and is suitable for high-temperature thermo-oxidative degradation; iron stearate has both lubricity and dispersibility, and can be activated at a lower temperature, which helps to achieve uniform degradation; by combining the two, the effective degradation temperature window can be broadened, thereby achieving a good recycling effect of ultra-high molecular weight polyethylene waste. Attached Figure Description

[0038] Figure 1 The Tg curve is shown for the recovered polyethylene powder in Example 1.

[0039] Figure 2 This is a SEM image of the recovered polyethylene powder from Example 1. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] The sources of some components in the examples and comparative examples are as follows: Manganese acetylacetone, CAS No. 14284-89-0, was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. Ferric stearate, CAS No. 555-36-2, was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0042] Example 1 This embodiment provides a method for recycling ultra-high molecular weight polyethylene waste, including the following steps: Step S1: Place the ultra-high molecular weight polyethylene waste in a nitrogen atmosphere and pretreat it at 120°C for 60 minutes to obtain pretreated polyethylene waste. Step S2: The pretreated polyethylene waste is subjected to electron beam irradiation treatment using a 1.5MeV electron accelerator, with an electron beam energy of 1.2MeV, a beam current of 2mA, and an irradiation dose of 100kGy, to obtain irradiated polyethylene waste. Step S3: Mix 60 parts of the radiation-treated polyethylene waste and 6 parts of degradation aid (4 parts of manganese acetylacetone and 2 parts of iron stearate) and then perform solid-phase treatment (milling pressure of 15 MPa, rotation speed of 60 r / min, and circulating cooling water temperature of 50 °C) to obtain polyethylene waste pulverized material. Step S4: Mix the polyethylene waste pulverized material with 600 parts of organic solvent benzene and perform high-temperature dissolution treatment (temperature is 150°C). Then add 600 parts of anhydrous ethanol to precipitate polyethylene. Separate the solid and liquid to obtain solid and liquid. Dry the solid into powder to obtain recycled polyethylene powder.

[0043] The liquid obtained from the solid-liquid separation in step S4 is recycled. The recycling process involves: first, distilling the liquid from the solid-liquid separation to obtain a mixture of recovered ethanol and solvent; then, cooling the solvent mixture to 20°C to precipitate and recover iron stearate; and finally, removing the solvent by rotary evaporation to obtain recovered manganese acetylacetone.

[0044] The Tg curve of the recovered polyethylene powder obtained in this embodiment is shown in the figure below. Figure 1 SEM image (see) Figure 2 .

[0045] Example 2 This embodiment provides a method for recycling ultra-high molecular weight polyethylene waste, including the following steps: Step S1: Place the ultra-high molecular weight polyethylene waste in a nitrogen atmosphere and pretreat it at 110°C for 80 minutes to obtain pretreated polyethylene waste. Step S2: The pretreated polyethylene waste is subjected to electron beam irradiation treatment using a 1.5MeV electron accelerator, with an electron beam energy of 1.2MeV, a beam current of 2mA, and an irradiation dose of 80kGy, to obtain irradiated polyethylene waste. Step S3: Mix 50 parts of the radiation-treated polyethylene waste and 4 parts of degradation aid (2 parts of manganese acetylacetone and 2 parts of iron stearate) and then perform solid-phase treatment (milling pressure of 10 MPa, rotation speed of 50 r / min, and circulating cooling water temperature of 40°C) to obtain polyethylene waste pulverized material. Step S4: Mix the pulverized polyethylene waste with 500 parts of organic solvent benzene and perform high-temperature dissolution treatment (temperature is 140°C). Then add 500 parts of anhydrous ethanol to precipitate polyethylene. Separate the solid and liquid to obtain solid and liquid. Dry the solid into powder to obtain recycled polyethylene powder.

[0046] The liquid obtained from the solid-liquid separation in step S4 is recycled. The recycling process involves: first, distilling the liquid from the solid-liquid separation to obtain a mixture of recovered ethanol and solvent; then, cooling the solvent mixture to 10°C to precipitate and recover iron stearate; and finally, removing the solvent by rotary evaporation to obtain recovered manganese acetylacetone.

[0047] Example 3 This embodiment provides a method for recycling ultra-high molecular weight polyethylene waste, including the following steps: Step S1: Place the ultra-high molecular weight polyethylene waste in a nitrogen atmosphere and pretreat it at 115°C for 70 minutes to obtain pretreated polyethylene waste. Step S2: The pretreated polyethylene waste is subjected to electron beam irradiation treatment using a 1.5MeV electron accelerator, with an electron beam energy of 1.2MeV, a beam current of 2mA, and an irradiation dose of 90kGy, to obtain irradiated polyethylene waste. Step S3: Mix 55 parts of the radiation-treated polyethylene waste and 5 parts of degradation aid (3 parts of manganese acetylacetone and 2 parts of iron stearate) and then perform solid-phase treatment (milling pressure of 12 MPa, rotation speed of 55 r / min, and circulating cooling water temperature of 45°C) to obtain polyethylene waste pulverized material. Step S4: Mix the polyethylene waste pulverized material with 550 parts of organic solvent benzene and perform high-temperature dissolution treatment (temperature is 145°C), then add 550 parts of anhydrous ethanol to precipitate polyethylene, and separate solid and liquid to obtain solid and liquid. Dry the solid into powder to obtain recycled polyethylene powder.

[0048] The liquid obtained from the solid-liquid separation in step S4 is recycled. The recycling process involves: first, distilling the liquid from the solid-liquid separation to obtain a mixture of recovered ethanol and solvent; then, cooling the solvent mixture to 15°C to precipitate and recover iron stearate; and finally, removing the solvent by rotary evaporation to obtain recovered manganese acetylacetone.

[0049] Comparative Example 1 The difference between this comparative example and Example 1 is that the irradiation dose in the electron beam radiation treatment was changed to 150 kGy.

[0050] Comparative Example 2 The difference between this comparative example and Example 1 is that the irradiation dose in the electron beam radiation treatment was changed to 50 kGy.

[0051] Comparative Example 3 The difference between this comparative example and Example 1 is that the degradation aid was changed to 6 parts of manganese acetylacetone.

[0052] Comparative Example 4 The difference between this comparative example and Example 1 is that the degradation aid was changed to 6 parts of ferric stearate.

[0053] Comparative Example 5 The difference between this comparative example and Example 1 is that the degradation aid is replaced with 5 parts manganese acetylacetone and 1 part ferric stearate.

[0054] Comparative Example 6 The difference between this comparative example and Example 1 is that the degradation aid is replaced with 1 part manganese acetylacetone and 5 parts ferric stearate.

[0055] Comparative Example 7 The difference between this comparative example and Example 1 is that the high-temperature melting treatment temperature was changed to 100°C.

[0056] Comparative Example 8 The difference between this comparative example and Example 1 is that the high-temperature melting treatment temperature was changed to 200°C.

[0057] Comparative Example 9 The difference between this comparative example and Example 1 is that no electron beam radiation treatment is performed.

[0058] Comparative Example 10 The difference between this comparative example and Example 1 is that no degradation aid is added.

[0059] Comparative Example 11 The difference between this comparative example and Example 1 is that the degradation aid was replaced with 6 parts of ammonium persulfate.

[0060] Performance testing Viscosity test: The test shall be conducted in accordance with the requirements of GB / T 1632.3-2010.

[0061] Sieve residue test: The test shall be conducted in accordance with the requirements of GB / T 21843-2008.

[0062] Density test: The test shall be conducted in accordance with the requirements of GB / T 1033.1-2008.

[0063] Apparent density test: The test shall be conducted in accordance with the requirements of GB / T 1636-2008.

[0064] Volatile matter test: The test shall be conducted in accordance with the requirements of GB / T 2914-2008.

[0065] Ash content test: The test shall be conducted in accordance with the requirements of GB / T 9345.1-2008.

[0066] Melt mass flow rate test: The test shall be conducted in accordance with the requirements of GB / T 3682.1-2018.

[0067] Table 1 Performance Test Results

[0068] The performance test results above show that Examples 1-3 have the best overall effect. This is mainly because they first pre-degrade the ultra-high molecular weight polyethylene waste through pretreatment and electron beam radiation oxidation treatment, then use manganese acetylacetone and iron stearate compound degradation aid for solid-phase treatment, followed by high-temperature dissolution treatment with organic solvent benzene, and then add alcohol solvent to precipitate polyethylene, thus achieving efficient recovery of polyethylene powder and obtaining good performance.

[0069] Compared to Example 1, in Comparative Example 1, the irradiation dose in the electron beam irradiation treatment was changed to 150 kGy. Due to the excessive irradiation dose, the effect was poor, and the performance of recovering polyethylene powder decreased. Compared to Example 1, in Comparative Example 2, the irradiation dose in the electron beam irradiation treatment was changed to 50 kGy. Due to the insufficient irradiation dose, the effect was poor, and the performance of recovering polyethylene powder decreased. Compared to Example 1, in Comparative Example 3, the degradation aid was changed to 6 parts of manganese acetylacetone. The lack of the compounding effect of ferric stearate resulted in a decrease in the performance of recovering polyethylene powder. Compared to Example 1, in Comparative Example 4, the degradation aid was changed to 6 parts of ferric stearate. The lack of the compounding effect of manganese acetylacetone resulted in a decrease in the performance of recovering polyethylene powder. Compared to Example 1, in Comparative Example 5, the degradation aid was changed to 5 parts of manganese acetylacetone and 1 part of ferric stearate. The excessive amount of manganese acetylacetone resulted in a poor compounding effect, and the performance of recovering polyethylene powder decreased. Compared to Example 1, in Comparative Example 6, the degradation aid was changed to 5 parts of manganese acetylacetone and 1 part of ferric stearate. The excessive amount of manganese acetylacetone resulted in a poor compounding effect, and the performance of recovering polyethylene powder decreased. The degrading agent was changed to 1 part manganese acetylacetone and 5 parts ferric stearate. Excessive use of ferric stearate resulted in poor compounding effect, thus reducing the performance of polyethylene powder recovery. Compared to Example 1, the high-temperature dissolution treatment temperature in Comparative Example 7 was changed to 100°C. Due to the low temperature, the solubility was poor, and polyethylene recovery could not be achieved. Compared to Example 1, the high-temperature dissolution treatment temperature in Comparative Example 8 was changed to 200°C. Due to the high temperature, the activity of the degradation aid decreased, and polyethylene recovery could not be achieved. Compared to Example 1, electron beam radiation treatment was not performed in Comparative Example 9. Without the effect of electron beam radiation treatment, polyethylene recovery could not be achieved. Compared to Example 1, no degradation aid was added in Comparative Example 10. Without the effect of the degradation aid, polyethylene recovery could not be achieved. Compared to Example 1, the degradation aid in Comparative Example 11 was changed to 6 parts ammonium persulfate. Due to the poor effect of ammonium persulfate, the performance of polyethylene powder recovery decreased.

Claims

1. A method for recycling ultra-high molecular weight polyethylene waste. Its features are, Includes the following steps: Step S1: Pre-treat the ultra-high molecular weight polyethylene waste to obtain pre-treated polyethylene waste; Step S2: The pretreated polyethylene waste is subjected to electron beam irradiation treatment under the following conditions: a 1.5MeV electron accelerator is used, the electron beam energy is 1.2MeV, the beam current is 2mA, and the irradiation dose is 80~100kGy, to obtain irradiated polyethylene waste. Step S3: Mix the radiation-treated polyethylene waste and the degradation aid and then perform solid-phase treatment to obtain polyethylene waste pulverized material; the degradation aid is manganese acetylacetone and iron stearate, with a mass ratio of (1~2):1; Step S4: Mix the polyethylene waste pulverized material with an organic solvent and dissolve it at a high temperature of 140~150℃. Then add an alcohol solvent to precipitate polyethylene. Separate the solid and liquid to obtain a solid and a liquid. Dry the solid into powder to obtain recycled polyethylene powder.

2. The method for recycling ultra-high molecular weight polyethylene waste according to claim 1, characterized in that, The pretreatment conditions in step S1 are as follows: place the sample in a nitrogen atmosphere and pretreat it at 110~120℃ for 60~80 minutes.

3. The method for recycling ultra-high molecular weight polyethylene waste according to claim 1, characterized in that, By weight, in step S3, the amount of polyethylene waste subjected to radiation treatment is 50-60 parts, and the amount of degradation aid is 4-6 parts. In step S4, the amount of organic solvent is 500-600 parts and the amount of alcohol solvent is 500-600 parts.

4. The method for recycling ultra-high molecular weight polyethylene waste according to claim 1, characterized in that, The organic solvent in step S4 is benzene; In step S4, the alcohol solvent is anhydrous ethanol.

5. The method for recycling ultra-high molecular weight polyethylene waste according to claim 1, characterized in that, The liquid obtained from the solid-liquid separation in step S4 is recycled. The recycling process involves: first, distilling the liquid from the solid-liquid separation to obtain a mixture of recovered ethanol and solvent; then, cooling the solvent mixture to 10-20°C to precipitate and recover iron stearate; and finally, removing the solvent by rotary evaporation to obtain recovered manganese acetylacetone.

6. The method for recycling ultra-high molecular weight polyethylene waste according to claim 1, characterized in that, The recycled polyethylene powder has a sieve residue of ≤1% and a density of 0.93~0.96 g / cm³. 3 The apparent density is 0.2~0.4 g / cm³. 3 Volatile matter ≤0.5%.

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