RAP fine separation aged asphalt deep fusion regeneration method, regeneration system and regenerated asphalt mixture

Abstract

The invention relates to the technical field of road material regeneration, in particular to an RAP fine separation aged asphalt deep fusion regeneration method, a regeneration system and a regenerated asphalt mixture. According to the regeneration method, the aged asphalt in the RAP is effectively removed through combination of fine separation and supercritical extraction, then the aged asphalt is activated and permeated through the targeted regeneration agent, the rheological property of the asphalt is directionally recovered, finally, fusion regeneration is performed at low temperature, high-temperature secondary aging is avoided, and the performance recovery rate of the regenerated asphalt can be remarkably increased.

Description

Technical Field

[0001] This invention relates to the field of road material recycling technology, specifically to a recycling method for fine separation and deep fusion of aged asphalt in reclaimed asphalt pavement (RAP), a recycling system, and a recycled asphalt mixture obtained based on the method. Background Technology

[0002] The existing recycling technology for reclaimed asphalt pavement (RAP) mainly suffers from the following problems: (1) Low separation efficiency: Traditional mechanical crushing makes it difficult to achieve fine separation between aged asphalt and aggregates, resulting in unstable performance of recycled mixtures. (2) Poor permeability of recycling agents: Aged asphalt hardens due to oxidation, making it difficult for recycling agents to penetrate effectively, resulting in insufficient asphalt performance recovery rate (usually only 60-70%). (3) Energy consumption and pollution: High-temperature treatment (>160℃) easily causes secondary aging of asphalt, and when a high proportion of RAP is added, additional new asphalt needs to be added, increasing costs. Therefore, it is urgent to improve the existing RAP recycling technology. Summary of the Invention

[0003] The purpose of this invention is to provide a regeneration technology for RAP (Rapidly Aerated Asphalt) that involves fine separation and deep fusion, addressing the limitations of existing technologies. This technology achieves efficient regeneration of aged asphalt in RAP through multi-stage fine separation, gradient activation and in-situ fusion regeneration.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] In a first aspect, the present invention provides a regeneration method for finely separating and deeply integrating aged asphalt using RAP, comprising the following steps:

[0006] 1) Fine separation of aged asphalt: The RAP raw material is crushed and graded, and aged asphalt is obtained by air classification combined with supercritical C5 extraction.

[0007] 2) Activation and penetration: The aged asphalt obtained in step 1) is coated with a regenerating agent and activated by penetration to obtain activated asphalt; the regenerating agent includes petroleum-based distillate oil, aromatic plasticizer and nano silica;

[0008] 3) Fusion Regeneration: Under the protection of inert gas, the activated asphalt is mixed with fresh asphalt at <160℃ to obtain recycled asphalt binder.

[0009] This method effectively removes aged asphalt from RAP through fine grading combined with supercritical extraction, then activates and penetrates the aged asphalt with a targeted regenerator to restore the rheological properties of the asphalt in a directional manner, and finally fuses and regenerates it at low temperature to avoid secondary aging at high temperature, which can significantly improve the performance recovery rate of recycled asphalt.

[0010] Preferably, the conditions for supercritical C5 extraction are: pressure 10-15 MPa, temperature 40-60℃, which can remove more than 85% of the aged asphalt in PAR.

[0011] Preferably, the petroleum-based distillate oil in the regenerator is one or more of vacuum distillation third-line base oil, vacuum distillation fourth-line base oil, or vacuum distillation second-line base oil.

[0012] Preferably, the aromatic plasticizer in the regenerator is one or more of C12-C18 alkyl sulfonate phenyl ester, phthalate ester, benzene polycarboxylic acid ester, and polyethylene naphthalate derivative.

[0013] Preferably, the regenerant comprises 60-70 parts by weight of petroleum-based distillate oil, 20-30 parts by weight of aromatic plasticizer, and 5-10 parts by weight of nano-silica.

[0014] Preferably, the ratio of regenerator to aged asphalt is 1-3:7-8 by weight.

[0015] Preferably, pulsed microwave radiation is used for penetration activation, which can enable the regenerator to quickly penetrate into the microporous structure of asphalt and improve penetration efficiency.

[0016] More preferably, the pulsed microwave radiation conditions are: frequency 2.45 GHz, power 300-500 W, and time 30-60 s, which can increase the penetration efficiency by more than 40%.

[0017] Preferably, in step 3), a twin-screw extruder is used for mixing, with the extruder temperature at 130-150°C and a shear rate of 100-200 s. -1 Low-temperature (<160℃) in-situ fusion avoids secondary aging of asphalt and achieves in-situ cross-linking and recombination of new and old asphalt molecular chains to form homogeneous recycled asphalt.

[0018] Preferably, in step 3), the ratio of activated asphalt to fresh asphalt is 1:0-1 by weight.

[0019] In a second aspect, the present invention provides a recycled asphalt mixture, which is made by mixing recycled asphalt binder and aggregate obtained by the above method, wherein the aggregate can be the aggregate separated in step 1) of the above method, or fresh aggregate, or a combination thereof.

[0020] A third aspect of the present invention provides a regeneration system for RAP fine separation and deep fusion of aged asphalt, comprising:

[0021] A pretreatment unit, comprising a crusher and a screening machine, is used to crush and classify RAP raw materials;

[0022] The separation unit, including an air classifier and a supercritical C5 extraction tank, is used to sort and extract pretreated RAP using supercritical C5 to obtain aged asphalt.

[0023] The activation unit, including a microwave radiation cavity and a regenerator mixing tank, is used to penetrate and activate the aged asphalt to obtain activated asphalt.

[0024] The fusion unit includes a twin-screw extruder for mixing the activated bitumen with fresh bitumen to obtain recycled bitumen binder.

[0025] Furthermore, the system may also include a mixing unit for mixing the obtained recycled asphalt binder with aggregates to obtain a recycled asphalt mixture.

[0026] The beneficial effects of this invention are:

[0027] This invention combines fine grading and separation, regeneration and activation, and low-temperature fusion regeneration to achieve efficient separation, activation, and deep regeneration of aged asphalt in RAP. Mechanical sieving combined with supercritical extraction enables the fine recovery of aged asphalt from RAP; the targeted regenerator formulation utilizes petroleum-based distillate oil softening, aromatic supplementation of light components, and nanoparticle reinforcement to synergistically restore the rheological properties of asphalt. Furthermore, microwave penetration coupled with dynamic shear avoids secondary aging caused by high temperatures, resulting in well-restored recycled asphalt binder properties. The recycled asphalt mixture prepared by mixing it with aggregates exhibits a dynamic stability ≥4000 cycles / mm and a water stability >95%. This invention also provides a regeneration system that can be used for the fine separation of aged asphalt in RAP, achieving deep fusion regeneration. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the RAP fine separation and deep fusion regeneration method for asphalt according to the present invention;

[0029] Figure 2 This is a schematic diagram of the RAP fine separation and deep fusion regeneration method for asphalt according to Embodiment 1 of the present invention;

[0030] Figure 3 This is a schematic diagram of the regeneration system structure for RAP fine separation and deep fusion of aged asphalt according to the present invention. Detailed Implementation

[0031] refer to Figure 1 This invention provides a regeneration method for finely separating and deeply integrating aged asphalt using RAP, comprising the following steps:

[0032] 1) Fine separation of aged asphalt: The RAP raw material is crushed and graded, and aged asphalt is obtained by air classification combined with supercritical C5 extraction.

[0033] 2) Activation and penetration: The aged asphalt obtained in step 1) is coated with a recycling agent, which penetrates and activates the asphalt to obtain activated asphalt;

[0034] 3) Fusion Regeneration: Under the protection of inert gas, the activated asphalt is mixed with fresh asphalt at <160℃ to form recycled asphalt binder.

[0035] In the embodiments of the present invention, aged asphalt is obtained by air classification combined with supercritical extraction. Air classification can remove light aged asphalt powder and some small aggregate particles (<0.3mm), and also facilitates the subsequent extraction and separation of aged asphalt. The combined effect of the two methods can achieve an aged asphalt recovery rate of more than 90%.

[0036] Supercritical C5 typically refers to pentane (C5H12) or its isomers (such as n-pentane, isopentane, and neopentane) in a supercritical state. In this embodiment of the invention, extraction is performed using n-pentane in a supercritical state.

[0037] In the embodiments of the present invention, the conditions for supercritical C5 extraction are: pressure 10-15 MPa and temperature 40-60°C, which can remove more than 85% of the aged asphalt in PAR. For example, the pressure can be 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, etc., and the temperature can be 40°C, 45°C, 50°C, 55°C, 60°C, etc., but are not limited to these.

[0038] In embodiments of the present invention, the regenerator includes petroleum-based distillate oil, aromatic plasticizer, and nano-silica; wherein the petroleum-based distillate oil acts as a softener, the aromatics supplement the light components, and the nanoparticles provide reinforcement, synergistically restoring the rheological properties of asphalt; wherein the petroleum-based distillate oil can be a vacuum distillation distillate oil with a boiling point ≥350℃, such as one or more of vacuum distillation second-line base oil with a boiling point of 350-450℃, vacuum distillation third-line base oil with a boiling point of 450-550℃, or vacuum distillation fourth-line base oil with a boiling point ≥550℃. The aromatic plasticizer can be one or more of C12-C18 alkyl sulfonate phenyl ester, phthalate ester, benzene polycarboxylic acid ester, and polyethylene naphthalate derivative.

[0039] In some preferred embodiments, the regenerator comprises 60-70 parts by weight of petroleum-based distillate oil, 20-30 parts by weight of aromatic plasticizer, and 5-10 parts by weight of nano-silica.

[0040] In an embodiment of the present invention, the ratio of recycler to aged asphalt by weight is 1-3:7-8. Compared with the traditional plant-mixed hot recycling process, the amount of recycler used can be reduced by nearly half.

[0041] In embodiments of the present invention, pulsed microwave radiation can be used for the penetration activation of the regenerator, which allows the regenerator to quickly penetrate into the microporous structure of asphalt, improving penetration efficiency, rapidly softening aged asphalt, and minimizing temperature rise. In some preferred embodiments, the pulsed microwave radiation conditions are: frequency 2.45 GHz, power 300-500 W, and time 30-60 s, which can increase the penetration efficiency by more than 40%.

[0042] In embodiments of the present invention, during fusion recycling, a twin-screw extruder can be used for mixing. Aged asphalt and fresh asphalt are connected through cross-linking points, with silica nanoparticles embedded in the molecular chain gaps to enhance interfacial bonding. Furthermore, microwave penetration combined with dynamic shear coupling avoids secondary aging caused by high temperatures, resulting in a regeneration rate of ≥95% for the asphalt binder's properties. In some preferred embodiments, the extruder temperature is 130-150°C, and the shear rate is 100-200 s. -1 Specifically, the extruder temperature can be 130℃, 135℃, 140℃, 145℃, 150℃, etc., and the shear rate can be 100s. -1 120s -1 150s -1 170s -1 200s -1 And so on, but not limited to these.

[0043] In embodiments of the present invention, during fusion recycling, the ratio of activated asphalt to fresh asphalt is 1:0-1 by weight. Because the activation method of the present invention can effectively improve the performance of aged asphalt and significantly reduce the amount of fresh asphalt used, it reduces the amount of new asphalt used by more than 30% compared to traditional plant-mixed hot recycling processes.

[0044] The recycled asphalt binder obtained by the recycling method of this invention can be mixed with aggregates to obtain recycled asphalt mixtures. The aggregates can be the aggregates separated in step 1) of the above method, fresh aggregates, or a combination thereof. The aggregates separated in step 1) of the above method can fully recycle RAP, increasing its utilization rate by 50-70%, while reducing the amount of new asphalt used by more than 30% compared to traditional methods. Compared to the loose structure obtained by traditional plant-mixed hot recycling processes, the recycled asphalt mixture of this invention can form a dense cross-linked network internally, with a dynamic stability ≥4000 cycles / mm and a water stability >95%. Furthermore, compared to traditional plant-mixed hot recycling processes, the fusion recycling process has a lower temperature (20-30°C lower), which can reduce carbon emissions by 15-20%. Figure 3 The present invention also provides a regeneration system for RAP fine separation and deep fusion of aged asphalt, comprising:

[0045] The pretreatment unit 100 includes a crusher 101 and a screening machine 102, which are used to crush and classify the RAP raw materials.

[0046] The separation unit 200 includes an air classifier 201 and a supercritical carbon 5 extraction tank 202, which are used to sort and extract RAP using supercritical carbon 5 to separate aged asphalt.

[0047] The activation unit 300 includes a microwave radiation cavity 301 and a regenerator mixing tank 302, which is used to activate the aged asphalt to obtain activated asphalt.

[0048] The blending unit 400 includes a twin-screw extruder 401 for mixing the activated bitumen with fresh bitumen to form homogeneous recycled bitumen.

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with specific examples. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0050] Example 1

[0051] refer to Figure 2 A regeneration method for finely separating and deeply integrating aged asphalt using RAP (Rapid Aponic Technology) includes the following steps:

[0052] 1) Take a sample of RAP (Railway Panel) from a highway, crush and classify it to obtain 0-3mm particles.

[0053] 2) Aging asphalt powder with a particle size <0.3mm (accounting for 35wt%) was separated by air classification. The remaining material was subjected to supercritical carbon 5 extraction at a pressure of 13MPa and a temperature of 45℃ to remove the surface asphalt and obtain aging asphalt powder. The remaining aggregate was reserved for use.

[0054] 3) The aged asphalt powder and the regenerator were mixed evenly at a mass ratio of 7:3, and microwave irradiation was performed at a frequency of 2.45 GHz and a power of 450 W for 45 s to obtain activated asphalt; wherein the regenerator was composed of 65 parts by weight of vacuum distilled three-line base oil, 25 parts by weight of C12-C18 alkyl sulfonate phenyl ester and 10 parts by weight of nano silica.

[0055] 4) The activated asphalt powder and fresh asphalt (PG 64-22) are mixed at a weight ratio of 1:1 and dynamically blended in a twin-screw extruder (140℃, 150s-1) to obtain recycled asphalt binder.

[0056] Example 2

[0057] refer to Figure 2 A regeneration method for finely separating and deeply integrating aged asphalt using RAP (Rapid Aponic Technology) includes the following steps:

[0058] 1) Take a sample of RAP (Railway Panel) from a highway, crush and classify it to obtain 0-3mm particles.

[0059] 2) Aging asphalt powder with a particle size <0.3mm (accounting for 35wt%) was separated by air classification. The remaining material was subjected to supercritical carbon 5 extraction at a pressure of 12MPa and a temperature of 60℃ to remove the surface asphalt and obtain aging asphalt powder. The remaining aggregate was reserved for use.

[0060] 3) The aged asphalt powder and the regenerator were mixed evenly at a mass ratio of 7:3, and microwave irradiation was performed at a frequency of 2.45 GHz and a power of 450 W for 45 s to obtain activated asphalt; wherein the regenerator was composed of 70 parts by weight of vacuum distilled second-line base oil, 25 parts by weight of C12-C18 alkyl sulfonate phenyl ester and 10 parts by weight of nano silica.

[0061] 4) The activated asphalt powder and fresh asphalt (PG 64-22) are mixed at a weight ratio of 1:1 and dynamically blended in a twin-screw extruder (130℃, 150s-1) to obtain recycled asphalt binder.

[0062] Example 3

[0063] refer to Figure 2 A regeneration method for finely separating and deeply integrating aged asphalt using RAP (Rapid Aponic Technology) includes the following steps:

[0064] 1) Take a sample of RAP (Railway Panel) from a highway, crush and classify it to obtain 0-3mm particles.

[0065] 2) Aging asphalt powder with a particle size <0.3mm (accounting for 35wt%) was separated by air classification. The remaining material was subjected to supercritical carbon 5 extraction at a pressure of 15MPa and a temperature of 40℃ to remove surface asphalt and obtain aging asphalt powder. The remaining aggregate was reserved for use.

[0066] 3) The aged asphalt powder and the regenerator were mixed evenly at a mass ratio of 9:1, and microwave irradiation was performed at a frequency of 2.45 GHz and a power of 500 W for 30 s to obtain activated asphalt; wherein the regenerator was composed of 60 parts by weight of vacuum distilled fourth-line base oil, 25 parts by weight of C12-C18 alkyl sulfonate phenyl ester and 10 parts by weight of nano silica.

[0067] 4) The activated asphalt powder and fresh asphalt (PG 64-22) are mixed at a weight ratio of 1:1 and dynamically blended in a twin-screw extruder (150℃, 200s-1) to obtain recycled asphalt binder.

[0068] Example 4

[0069] refer to Figure 2 A regeneration method for finely separating and deeply integrating aged asphalt using RAP (Rapid Aponic Technology) includes the following steps:

[0070] 1) Take a sample of RAP (Railway Panel) from a highway, crush and classify it to obtain 0-3mm particles.

[0071] 2) Aging asphalt powder with a particle size <0.3mm (accounting for 35wt%) was separated by air classification. The remaining material was subjected to supercritical carbon 5 extraction at a pressure of 13MPa and a temperature of 40℃ to remove surface asphalt and obtain aging asphalt powder. The remaining aggregate was reserved for use.

[0072] 3) The aged asphalt powder and the regenerator were mixed evenly at a mass ratio of 8:2, and microwave irradiation was performed at a frequency of 2.45 GHz and a power of 450 W for 30 seconds to obtain activated asphalt; wherein the regenerator was composed of 70 parts by weight of vacuum distilled triple base oil, 25 parts by weight of phthalate and 10 parts by weight of nano silica.

[0073] 4) The activated asphalt powder and fresh asphalt (PG 64-22) are mixed at a weight ratio of 1:1 and dynamically blended in a twin-screw extruder (130℃, 200s-1) to obtain recycled asphalt binder.

[0074] Comparative Example 1

[0075] The difference from Example 1 is that air separation is not performed; all other steps are the same. The specific steps are as follows:

[0076] 1) Take a sample of RAP (Railway Panel) from a highway, crush and classify it to obtain 0-3mm particles.

[0077] 2) The surface asphalt was removed by supercritical carbon-5 extraction at a pressure of 13 MPa and a temperature of 45 °C to obtain aged asphalt powder, and the remaining aggregate was used for future reference.

[0078] 3) The aged asphalt powder and the regenerator were mixed evenly at a mass ratio of 7:3, and microwave irradiation was performed at a frequency of 2.45 GHz and a power of 450 W for 45 s to obtain activated asphalt; wherein the regenerator consisted of 65 parts by weight of vacuum distilled three-line base oil, 25 parts by weight of C12-C18 alkyl sulfonate phenyl ester and 10 parts by weight of nano silica.

[0079] 4) The activated asphalt powder and fresh asphalt (PG 64-22) are mixed at a weight ratio of 1:1 and dynamically blended in a twin-screw extruder (140℃, 150s-1) to obtain recycled asphalt binder.

[0080] Comparative Example 2

[0081] The difference from Example 1 is that the regenerator contains only petroleum-based distillate oil, while the rest are the same. The specific steps are as follows:

[0082] 1) Take a sample of RAP (Railway Panel) from a highway, crush and classify it to obtain 0-3mm particles.

[0083] 2) Aging asphalt powder with a particle size <0.3mm (accounting for 35wt%) was separated by air classification. The remaining material was subjected to supercritical carbon 5 extraction at a pressure of 13MPa and a temperature of 45℃ to remove the surface asphalt and obtain aging asphalt powder. The remaining aggregate was reserved for use.

[0084] 3) The aged asphalt powder and the rejuvenator were mixed evenly at a mass ratio of 7:3, and microwave irradiation was performed at a frequency of 2.45 GHz and a power of 450 W for 45 s to obtain activated asphalt; wherein the rejuvenator was composed of 65 parts by weight of vacuum distilled three-line base oil.

[0085] 4) The activated asphalt powder and fresh asphalt (PG 64-22) are mixed at a weight ratio of 1:1 and dynamically blended in a twin-screw extruder (140℃, 150s-1) to obtain recycled asphalt binder.

[0086] Comparative Example 3

[0087] The difference from Example 1 is that the regenerator contains only aromatic plasticizer and petroleum-based distillate oil; all other steps are the same. The specific steps are as follows:

[0088] 1) Take a sample of RAP (Railway Panel) from a highway, crush and classify it to obtain 0-3mm particles.

[0089] 2) Aging asphalt powder with a particle size <0.3mm (accounting for 35wt%) was separated by air classification. The remaining material was subjected to supercritical carbon 5 extraction at a pressure of 13MPa and a temperature of 45℃ to remove the surface asphalt and obtain aging asphalt powder. The remaining aggregate was reserved for use.

[0090] 5) The aged asphalt powder and the regenerator are mixed evenly at a mass ratio of 7:3, and microwave irradiation is performed at a frequency of 2.45 GHz and a power of 450 W for 45 s to obtain activated asphalt; wherein the regenerator is composed of 65 parts by weight of vacuum distilled three-line base oil and 25 parts by weight of C12-C18 alkyl sulfonate phenyl ester.

[0091] 3) The activated asphalt powder and fresh asphalt (PG 64-22) are mixed at a weight ratio of 1:1 and dynamically blended in a twin-screw extruder (140℃, 150s-1) to obtain recycled asphalt binder.

[0092] Comparative Example 4

[0093] The difference from Example 1 is that the regeneration and activation process uses mixing, while the rest are the same. The specific steps are as follows:

[0094] 1) Take a sample of RAP (Railway Panel) from a highway, crush and classify it to obtain 0-3mm particles.

[0095] 2) Aging asphalt powder with a particle size <0.3mm (accounting for 35wt%) was separated by air classification. The remaining aggregate was subjected to supercritical carbon 5 extraction at a pressure of 13MPa and a temperature of 45℃ to remove surface asphalt and separate aging asphalt powder. The remaining aggregate was used for future reference.

[0096] 3) Mix the obtained aged asphalt powder and recycling agent at a mass ratio of 7:3 until homogeneous, then heat at 130℃.

[0097] Stir and mix for 5 minutes at a stirring speed of 200 rpm to obtain activated asphalt; the regenerator is composed of 65 parts by weight of vacuum distilled third-line base oil, 25 parts by weight of C12-C18 alkyl sulfonate phenyl ester and 10 parts by weight of nano silica.

[0098] 4) The activated asphalt powder and fresh asphalt (PG 64-22) are mixed at a weight ratio of 1:1 and dynamically blended in a twin-screw extruder (140℃, 150s-1) to obtain recycled asphalt binder.

[0099] Comparative Example 5

[0100] The same raw materials are used, but the difference lies in the use of a traditional plant-mixed hot recycling process. The specific steps are as follows:

[0101] (1) Use a crusher to crush the RAP to a particle size ≤30mm. Use a screening device to classify the crushed RAP and store it according to particle size (0~4.75mm, 4.75~9.5mm, etc.) for easy subsequent gradation adjustment.

[0102] (2) Performance testing and gradation design of old aggregate: Test the asphalt content, aggregate gradation and aging degree of RAP, and calculate the ratio of RAP to new aggregate according to the target gradation (AC, SMA).

[0103] (3) Preparation and mixing of new materials: According to the settlement results in step (2), prepare new aggregates (crushed stone, sand) and new asphalt; send RAP and new aggregates into the mixing equipment according to the design ratio, and add 10wt% of the recycling agent of Example 1 at the same time, and dry mix evenly.

[0104] (4) Heating and mixing: Heating RAP and new aggregate separately: RAP is heated to 150℃ and new aggregate is heated to 180℃; add new asphalt and wet mix for 30 seconds until the mixture is uniform and consistent, without white spots or clumping.

[0105] The experimental conditions for each embodiment and comparative example are shown in Table 1.

[0106] Table 1. Experimental conditions for examples and comparative examples

[0107]

[0108]

[0109] Performance testing:

[0110] The recycled asphalt binders obtained in Examples 1-4 and Comparative Examples 1-4 were mixed with the aggregates obtained separately in the same proportion to obtain recycled asphalt mixtures. The performance of each sample was tested in accordance with JTG 3640 "Technical Specification for Construction of Highway Asphalt Pavement" and compared with the mixture of the traditional plant-mixed hot recycling process in Comparative Example 5. The results are shown in Table 2.

[0111] Table 2 Performance test results of the examples and comparative examples

[0112]

[0113]

[0114] Moreover, compared with the traditional plant-mixed hot recycling method, in the embodiments of the present invention, the RAP utilization rate is increased to 50-70%, and the amount of new asphalt is reduced by more than 30%. The recycling temperature is reduced by 20-30°C, reducing carbon emissions by 15-20%. Taking Example 1 as a reference, the results compared with the traditional plant-mixed hot recycling method of Comparative Example 5 are shown in Table 3.

[0115] Table 3 Comparison of Example 1 and Comparative Example 5 (Table 3)

[0116] Comparative Example 5 Example 1 Asphalt recovery rate 40％ 96％ Regenerant dosage 10％ 6％ Energy consumption (kWh / t) 120 75

[0117] Example 7

[0118] refer to Figure 3 This embodiment provides a regeneration system for RAP fine separation and deep fusion of aged asphalt, comprising:

[0119] The pretreatment unit 100 includes a crusher 101 and a screening machine 102, used for crushing and classifying the RAP material; in some specific embodiments, the crusher 101 may be a jaw crusher. In some specific embodiments, the screening machine 102 may be a vibrating screen.

[0120] The separation unit 200, the air classifier 201, and the supercritical carbon 5 extraction tank 202 are used to sort and extract RAP using supercritical carbon 5 to remove the aged asphalt. In some specific embodiments, the air classifier 200 is a negative pressure air classifier.

[0121] The activation unit 300, microwave radiation cavity 301, and regenerant mixing tank 302 are used to activate the obtained aged asphalt to obtain activated asphalt. In some specific embodiments, the microwave radiation cavity 301 can be a cylindrical cavity with a microwave generator array at the top and a conveyor belt at the bottom. An annular nozzle is installed inside the cavity, communicating with the regenerant mixing tank 302, for spraying regenerant onto the aged asphalt passing on the conveyor belt. The microwave radiation cavity can be made of stainless steel. In some embodiments, a temperature sensor is also installed inside the microwave radiation cavity 301 for real-time temperature monitoring. In one embodiment, the microwave generator frequency is 2.45 GHz and the power is 300-500 W.

[0122] The fusion unit 400 includes a twin-screw extruder 401 for mixing activated bitumen with fresh bitumen to form a homogeneous recycled bitumen binder.

[0123] In some embodiments, the system may further include a mixing unit for mixing the obtained recycled asphalt binder with aggregates to obtain a recycled asphalt mixture. Specifically, the mixing unit may include a twin-shaft forced mixer.

[0124] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for the fine separation and deep fusion regeneration of aged asphalt using RAP, characterized in that, Includes the following steps: 1) Fine separation of aged asphalt; crushed and graded RAP raw materials, aged asphalt and aggregates are obtained by air classification combined with supercritical C5 extraction; 2) Activation and penetration: The aged asphalt obtained in step 1) is coated with a regenerating agent and activated by penetration to obtain activated asphalt; the regenerating agent includes petroleum-based distillate oil, aromatic plasticizer and nano silica; 3) Fusion Regeneration: Under the protection of inert gas, the activated asphalt is mixed with fresh asphalt at <160℃ to obtain recycled asphalt binder.

2. The RAP fine separation and deep fusion regeneration method for aged asphalt according to claim 1, characterized in that, The conditions for supercritical C5 extraction are: pressure 10-15 MPa and temperature 40-60℃.

3. The RAP fine separation and deep fusion regeneration method for aged asphalt according to claim 1, characterized in that, The petroleum-based distillate oil is one or more of the following: vacuum distillation third-line base oil, vacuum distillation fourth-line base oil, or vacuum distillation second-line base oil. And / or, the aromatic plasticizer is one or more of C12-C18 alkyl sulfonate phenyl ester, phthalate ester, benzene polycarboxylic acid ester, and polyethylene naphthalate derivative.

4. The RAP fine separation and deep fusion regeneration method for aged asphalt according to claim 1, characterized in that, The regenerant comprises 60-70 parts by weight of petroleum-based distillate oil, 20-30 parts by weight of aromatic plasticizer, and 5-10 parts by weight of nano-silica. And / or, by weight ratio, recycling agent: aged bitumen = 1-3: 7-8.

5. The RAP fine separation and deep fusion regeneration method for aged asphalt according to claim 1, characterized in that, Activation was achieved by pulsed microwave radiation.

6. The RAP fine separation and deep fusion regeneration method for aged asphalt according to claim 5, characterized in that, The pulsed microwave radiation conditions are: frequency 2.45 GHz, power 300-500 W, and time 30-60 s.

7. The RAP fine separation and deep fusion regeneration method for aged asphalt according to claim 1, characterized in that, In step 3), a twin-screw extruder is used for mixing, with an extrusion temperature of 130-150℃ and a shear rate of 100-200 s. -1 .

8. The RAP fine separation and deep fusion regeneration method for aged asphalt according to claim 1, characterized in that, In step 3), the ratio of activated asphalt to fresh asphalt is 1:0-1 by weight.

9. A recycled asphalt mixture, characterized in that, The method comprises recycled asphalt binder obtained by any one of claims 1-8 and aggregate, wherein the aggregate is the aggregate separated in step 1) of the method according to any one of claims 1-8 and / or fresh aggregate.

10. A RAP fine separation and deep fusion recycling system for aged asphalt, characterized in that, include: A pretreatment unit, comprising a crusher and a screening machine, is used to crush and classify RAP; The separation unit, including an air classifier and a supercritical C5 extraction tank, is used to sort and extract pretreated RAP using supercritical C5 to obtain aged asphalt. The activation unit, including a microwave radiation cavity and a regenerator mixing tank, is used for the penetration activation of aged asphalt; The fusion unit includes a twin-screw extruder for mixing activated bitumen with fresh bitumen to obtain recycled bitumen binder.

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