Multifunctional emulsified asphalt cold recycling continuous mixing station
Patent Information
- Application Number
- CN202611273685.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-21
- Publication Date
- 2026-11-03
AI Technical Summary
After long-term aging, the surface free energy of waste asphalt pavement materials decreases, resulting in insufficient adhesion to emulsified asphalt and poor water stability of the mixture, which limits the cold recycling rate and long-term durability.
Ozone room temperature oxidation treatment is introduced in the RAP pretreatment stage to improve surface free energy, and the mixture is uniformly mixed and early strength is accelerated through the CO2 curing channel. Carbon sequestration is carried out using CO2 exhaust gas.
It significantly improved the interfacial adhesion between RAP and emulsified asphalt, enhanced the water stability of the mixture, and improved the early strength and long-term durability of the mixture through carbon sequestration.
Smart Images
Figure CN123027780A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of asphalt recycling technology, and in particular to a multifunctional emulsified asphalt cold recycling continuous mixing plant. Background Technology
[0002] Emulsified asphalt cold recycling technology involves recycling waste asphalt pavement material (RAP) and mixing it with emulsified asphalt, new aggregates, cement, and other materials at room temperature to form a recycled mixture, which is then used to repave the road surface. This technology eliminates the need for high-temperature heating of the asphalt, avoiding thermo-oxidative aging and offering significant energy-saving and emission-reduction advantages. It represents an important technological direction for green and low-carbon road maintenance. As many early-built asphalt pavements in my country reach or exceed their design lifespan, the amount of waste asphalt pavement material generated annually is enormous and continues to grow. Due to its high utilization rate of recycled materials and its economic and environmental advantages, emulsified asphalt plant-mixed cold recycling technology is increasingly being promoted and applied in the field of pavement recycling.
[0003] However, recycled asphalt pavement (RAP) undergoes significant aging under long-term exposure to light, heat, oxygen, and other factors. This results in a substantial decrease in the surface free energy and poorer wettability compared to virgin aggregates. Consequently, the interfacial adhesion work between different materials is low, and emulsifier molecules can only form weak adsorption on the aged asphalt surface, leading to insufficient interfacial bonding. In cold-recycled emulsified asphalt mixture systems, uneven adhesion between cement emulsified asphalt mortar and RAP is common. Furthermore, the mixture is prone to interfacial spalling upon contact with water, directly reducing its water stability and other key road performance characteristics. This limits the recycling rate of RAP and negatively impacts the long-term durability of cold-recycled asphalt pavements. Summary of the Invention
[0004] To address the aforementioned shortcomings, a continuous cold recycling mixing plant for emulsified asphalt is provided. By introducing ozone at room temperature during the RAP pretreatment stage for surface activation treatment, the surface free energy of RAP and its adhesion to emulsified asphalt are improved. The uniform mixing of the mixture and the accelerated development of early strength are achieved through two-stage mixing and CO2 curing channels. The CO2 tail gas generated by ozone oxidation of RAP is used for carbon sequestration curing of the mixture.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a multifunctional emulsified asphalt cold recycling continuous mixing plant, comprising an asphalt emulsification recycling system, wherein the asphalt emulsification recycling system includes a primary mixing tank, a secondary mixing tank, and a CO2 curing channel; the feed end of the primary mixing tank is connected to a RAP pretreatment system; the RAP pretreatment system includes a RAP silo; the discharge end of the RAP silo is connected to a sealed conveying device; the air inlet of the sealed conveying device is connected to an ozone generator; the air outlet of the sealed conveying device is connected to the air inlet side of the first catalytic bed of a carbon dioxide supply system; and the air outlet side of the first catalytic bed is connected to the air inlet side of the second catalytic bed. The outlet side of the second catalytic bed is connected to the inlet of the carbon dioxide storage tank. The feed end of the first-stage mixing cylinder is also connected to the new material supply system containing new aggregates and cement powder. The discharge end of the first-stage mixing cylinder is connected to the feed end of the second-stage mixing cylinder. The feed end of the second-stage mixing cylinder is also connected to various pipelines of the new material supply system. The discharge end of the second-stage mixing cylinder is connected to the feed end of the CO2 curing channel. The CO2 curing channel has an inlet connected to the carbon dioxide storage tank of the carbon dioxide supply system. The outlet of the CO2 curing channel is connected to the waste gas tank of the carbon dioxide supply system. The discharge end of the CO2 curing channel is connected to the finished product discharge system.
[0006] As a further improvement of the present invention, a RAP metering belt scale is provided between the RAP silo and the sealed conveying device.
[0007] As a further improvement of the present invention, the new material supply system includes a new aggregate cold silo and several powder silos, and the discharge ends of the new aggregate cold silo and the powder silos are connected to the asphalt emulsion recycling system through the new material output device 304.
[0008] As a further improvement of the present invention, a new material metering belt scale is provided between the new aggregate cold silo and the powder silo and the new material output device 304.
[0009] As a further improvement of the present invention, the new material supply system includes an emulsified asphalt storage tank, a water tank, and an additive tank. The outlet of the emulsified asphalt storage tank is connected to the secondary mixing cylinder through an asphalt pump and pipeline. The outlet of the water tank is connected to the secondary mixing cylinder through a water pump and pipeline. The additive tank stores regenerator and reinforcing agent, and its outlet is connected to the secondary mixing cylinder through a metering pump and pipeline.
[0010] As a further improvement of the present invention, the water tank is equipped with a level gauge and an automatic water replenishment device.
[0011] As a further improvement of the present invention, the first catalyst bed uses a MnO2 / γ-Al2O3 catalyst bed to decompose ozone, and the second catalyst bed uses an activated carbon adsorption bed to absorb impurity gases.
[0012] As a further improvement of the present invention, the finished product discharge system includes a discharge bin, the inlet of which is connected to the outlet of the CO2 curing channel via a finished product conveyor belt, and a discharge gate is provided at the bottom of the discharge bin.
[0013] The beneficial effects of this invention are: 1. This application introduces ozone oxidation treatment at room temperature during the RAP pretreatment stage. Ozone molecules and the oxygen free radicals generated by their decomposition react with aged asphalt molecules on the RAP surface, oxidizing the hydrocarbons on the aged asphalt surface and introducing polar oxygen-containing functional groups such as carbonyl and carboxyl groups, significantly increasing the surface free energy of the RAP. After ozone oxidation treatment, the surface polarity of the RAP is enhanced, the wettability of the emulsified asphalt on the RAP surface is greatly improved, and the interfacial adhesion work between the two is significantly increased. Therefore, the water stability of the recycled mixture is fundamentally improved, effectively solving the problems of insufficient adhesion between RAP and emulsified asphalt and poor water stability of the mixture in existing cold recycling technologies.
[0014] 2. The carbon dioxide-containing exhaust gas generated during the ozone oxidation of RAP surfaces is recovered. The exhaust gas sequentially passes through a catalytic bed to decompose residual ozone and an activated carbon adsorption bed to remove impurities. The purified carbon dioxide is then introduced into the CO2 curing channel of the mixture. The greenhouse gas carbon dioxide undergoes a mineralization reaction to generate stable, water-insoluble calcium carbonate, which is permanently fixed within the mixture, transforming the mixing plant from a carbon emission source to a carbon sequestration unit—a more environmentally friendly approach. Simultaneously, the generated calcium carbonate effectively improves the early strength and compaction density of cold recycled asphalt mixtures, optimizing the long-term performance of the material under complex service environments. This mineralization product possesses both good stability and particle-filling properties. The mixture cured by mineralization exhibits improved mechanical strength and durability. Compared to conventional curing processes, high-performance recycled mixtures can be prepared within a shorter curing cycle. Applying this technical approach to the cold recycled asphalt mixture system can accelerate the formation of early strength in the mixture and significantly improve the long-term durability of recycled asphalt pavements. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the multifunctional emulsified asphalt cold recycling continuous mixing plant system of the present invention; Figure 2 This is a schematic diagram of the RAP preprocessing system; Figure 3 This is a schematic diagram of a carbon dioxide supply system; Figure 4 This is a schematic diagram of the new material supply system; Figure 5 This is a schematic diagram of the new material supply system; Figure 6 This is a schematic diagram of an asphalt emulsification and recycling system and a finished product discharge system.
[0016] In the diagram: 1-RAP pretreatment system, 101-RAP silo, 102-RAP metering belt scale, 103-sealed conveyor device, 104-ozone generator, 105-air inlet, 106-air outlet. 2-Carbon dioxide supply system, 201-First catalytic bed, 202-Second catalytic bed, 203-Carbon dioxide storage tank, 204-Carbon dioxide delivery pipe, 205-Waste gas tank, 206-Waste gas pipeline; 3-New material feeding system, 301-New aggregate cold silo, 302-Powder silo, 303-New material metering belt scale, 304-New material output device; 4-New material supply system, 401-Emulsified asphalt storage tank, 402-Asphalt pump, 403-Water tank, 404-Water pump, 405-Additive tank, 406-Metering pump; 5-Asphalt emulsification recycling system, 501-Primary mixing tank, 502-First conveyor belt, 503-Secondary mixing tank, 504-CO2 curing channel; 6-Finished product discharge system, 601-Finished product conveyor belt, 602-Unloading bin, 603-Unloading gate. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific examples described herein are merely illustrative and not intended to limit the invention. The directional terms used in the following embodiments, such as up, down, left, right, front, or back, are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the invention. Furthermore, in all embodiments, the same reference numerals denote the same elements.
[0018] Please see Figures 1 to 6 The present invention provides a multifunctional emulsified asphalt cold recycling continuous mixing plant, including a RAP pretreatment system 1, a new material feeding system 3, a new material liquid supply system 4, a carbon dioxide supply system 2, an asphalt emulsification recycling system 5, and a finished product discharge system 6.
[0019] The RAP pretreatment system 1 includes a RAP silo 101. Recycled asphalt pavement material entering the RAP silo 101 is pre-crushed by a crusher and dried. A RAP metering belt scale 102 is installed at the discharge end of the RAP silo 101 to measure the amount of recycled asphalt pavement material. The output end of the metering belt scale is connected to the feed end of a sealed conveyor 103. An air inlet 105 is located on the side of the sealed conveyor 103 near the feed end, and the air inlet 105 is connected to the outlet end of an ozone generator 104 via an air inlet pipe. An air outlet 106 is located on the side of the sealed conveyor 103 near the discharge end, and an air outlet pipe is connected to the carbon dioxide supply system 2 at the outlet 106. The material discharged from the discharge end of the sealed conveyor 103 is conveyed to the asphalt emulsion recycling system 5 via a conveying device.
[0020] As a further explanation of this embodiment, ozone generator 104 generates ozone gas which is introduced into sealed conveying device 103. RAP particles are weighed by RAP metering belt scale 102 and then enter sealed conveying device 103 in a thin layer. The ozone gas and the oxygen free radicals generated by its decomposition react with the aged asphalt molecules on the surface of the recycled asphalt pavement material, oxidizing the hydrocarbons on the surface of the aged asphalt and introducing polar oxygen-containing functional groups such as carbonyl (C=O) and carboxyl (-COOH). At the same time, the oxidation reaction degrades some organic matter on the surface of the aged asphalt into CO2 and H2O.
[0021] The virgin material feeding system 3 includes a virgin aggregate cold aggregate bin 301 and several powder bins 302, which respectively store cement, mineral powder, and hydrated lime. The discharge ends of both the virgin aggregate cold aggregate bin 301 and the several powder bins 302 are equipped with virgin material metering belt scales 303 for metering. The discharge ends of the virgin material metering belt scales 303 are all connected to a virgin material output device 304, and the discharge end of the virgin material output device 304 is connected to the asphalt emulsion recycling system 5.
[0022] The new material supply system 4 includes an emulsified asphalt storage tank 401 and a water tank 403. The outlet of the emulsified asphalt storage tank 401 is connected to the inlet of the asphalt pump 402, and the outlet of the asphalt pump 402 is connected to the asphalt emulsification and recycling system 5. Both the pipelines connecting the emulsified asphalt storage tank 401 and the asphalt pump 402 to the asphalt emulsification and recycling system 5 are equipped with insulation jackets to prevent the viscosity of the emulsified asphalt from increasing at low temperatures. The water tank 403 is equipped with a level gauge and an automatic water replenishment device. The outlet of the water tank 403 is connected to the inlet of the water pump 404, and the outlet of the water pump 404 is connected to the asphalt emulsification and recycling system 5. In addition, several additive tanks 405 are provided. The additive tanks 405 store special additives such as regenerators and reinforcing agents. The outlet of the additive tanks 405 is connected to the inlet of the metering pump 406, and the outlet of the metering pump 406 is connected to the asphalt emulsification and recycling system 5.
[0023] The carbon dioxide supply system 2 includes a first catalyst bed 201 and a second catalyst bed 202. The first catalyst bed 201 uses a MnO2 / γ-Al2O3 catalyst bed to decompose residual ozone, and the second catalyst bed 202 uses an activated carbon adsorption bed to absorb residual VOCs and other impurity gases. The inlet side of the first catalyst bed 201 is connected to the outlet 106 of the sealed conveying device 103, and the outlet side of the first catalyst bed 201 is connected to the inlet side of the second catalyst bed 202. The outlet side of the second catalyst bed 202 is connected to the inlet 105 of the carbon dioxide storage tank 203, and the outlet end of the carbon dioxide storage tank 203 is connected to the asphalt emulsion regeneration system 5 through a carbon dioxide delivery pipe 204.
[0024] The asphalt emulsification recycling system 5 includes a primary mixing tank 501, a secondary mixing tank 503, and a CO2 curing channel 504. Material discharged from the outlet of the sealed conveying device 103 of the RAP pretreatment system 1 is conveyed to the inlet of the primary mixing tank 501 via a conveying device. The inlet of the primary mixing tank 501 is also connected to the outlet of the new material output device 304 of the new material supply system 3. The outlet of the primary mixing tank 501 is connected to the inlet of the first conveyor belt 502, which is connected to the inlet of the secondary mixing tank 503. The inlet of the secondary mixing tank 503 is also connected to various pipelines of the new material supply system 4, and the outlet of the secondary mixing tank 503 is connected to the inlet of the CO2 curing channel 504. The CO2 curing channel 504 includes a sealed casing, inside which a conveying device is installed, and a device for slowly agitating the mixture is installed. The discharge end of the CO2 curing channel 504 is provided with an exhaust gas outlet, which is connected to the exhaust gas tank 205 of the carbon dioxide supply system 2 through an exhaust gas pipeline 206.
[0025] As a further explanation of this embodiment, CO2 reacts with Ca(OH)2, a cement hydration product in the mixture, to generate CaCO3, which accelerates the early strength development. At the same time, CO2 is permanently sequestered in the mixture, achieving carbon sequestration.
[0026] The discharge end of the CO2 curing channel 504 is connected to the inlet end of the inclined finished product conveyor belt 601 of the finished product discharge system 6. The discharge end of the finished product conveyor belt 601 is connected to the unloading hopper 602. The unloading hopper 602 is equipped with an unloading gate 603 at the bottom and has an internal insulation layer.
[0027] The working principle and usage process of this embodiment are as follows: Recycled asphalt pavement material (RAP) is pre-crushed to the required particle size and dried before being temporarily stored in RAP silo 101. A RAP metering belt scale 102 at the bottom of RAP silo 101 continuously weighs and measures the RAP, feeding it into a sealed conveying device 103 at a precisely controlled flow rate and in a thin layer. An ozone generator 104 generates ozone gas, which is introduced into the sealed conveying device 103 through an inlet pipe and inlet 105. In the sealed conveying device 103, the RAP particles come into full contact with the ozone gas. The ozone and the oxygen free radicals generated by its decomposition react with the aged asphalt molecules on the RAP surface, with the treatment time controlled between 1 and 10 minutes. After ozone oxidation treatment, polar oxygen-containing functional groups such as carbonyl and carboxyl groups are introduced into the RAP surface, significantly increasing its surface free energy and enhancing its adhesion to emulsified asphalt. Meanwhile, the CO2-containing tail gas generated by the oxidation reaction is discharged through the outlet 106 and sent to the carbon dioxide supply system 2; the activated RAP is discharged through the discharge end of the sealed conveying device 103 and sent to the primary mixing tank 501 of the asphalt emulsion recycling system 5 through the conveying device.
[0028] New aggregates are precisely weighed by the new aggregate metering belt scale 303 at the bottom of the new aggregate cold silo 301 and then fed into the primary mixing tank 501 via the new aggregate output device 304. Cement, mineral powder, hydrated lime, and other powders are precisely weighed by the new aggregate metering belt scale 303 at the bottom of their respective powder silos 302 and then fed into the primary mixing tank 501 via the new material output device 304. Activated RAP, new aggregates, cement, mineral powder, and hydrated lime are combined in the primary mixing tank 501 and subjected to forced dry mixing. No liquid components are added during the dry mixing stage, allowing the solid dry materials to be fully dispersed, breaking up agglomerated particles in the RAP, and ensuring that the cement and other powders are evenly distributed on the aggregate surface. The dry-mixed premix is then fed into the secondary mixing tank 503 via the first conveyor belt 502.
[0029] Emulsified asphalt in the emulsified asphalt storage tank 401 is metered by the asphalt pump 402 and then fed into the secondary mixing tank 503 through a pipe with an insulated jacket. Water in the water tank 403 is metered by the water pump 404 and then fed into the secondary mixing tank 503. Recycling agent, reinforcing agent, etc. in the additive tank 405 are precisely metered by the metering pump 406 and then fed into the secondary mixing tank 503. The premixed dry material from the primary mixing tank 501, along with the emulsified asphalt, water, and additives, undergoes forced wet mixing in the secondary mixing tank 503, ensuring that the emulsified asphalt is evenly coated on the surface of all solid particles, forming a homogeneous recycled mixture.
[0030] The mixed material enters the CO2 curing channel from the discharge end of the secondary mixing tank 503. High-purity CO2 from the CO2 storage tank is evenly introduced into the sealed chamber of the curing channel through a gas distributor, with the CO2 concentration controlled at 20-80%. The mixture is conveyed forward within the curing channel by a conveying device, while a low-speed agitator continuously agitates the mixture, ensuring sufficient contact between the CO2 and the material. The CO2 reacts with the cement hydration product Ca(OH)2 in the mixture at room temperature to form CaCO3, accelerating the early strength development of the mixture, while simultaneously sealing the CO2 within the mixture. Unreacted CO2 and exhaust gas in the curing channel are collected and treated in the exhaust gas tank 205 via the exhaust gas outlet and exhaust gas pipeline 206.
[0031] The finished mixture after curing is discharged from the outlet end of the CO2 curing channel and sent to the unloading hopper 602 via the inclined finished material conveyor belt 601. The finished mixture is temporarily stored in the unloading hopper 602 with an insulation layer, and the discharge speed is controlled by the unloading gate 603 to complete the finished product discharge.
[0032] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above-described embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.
Claims
1. A multifunctional emulsified asphalt cold recycling continuous mixing plant, characterized in that, The system includes an asphalt emulsification and recycling system (5), which includes a primary mixing tank (501), a secondary mixing tank (503), and a CO2 curing channel (504). The feed end of the primary mixing tank (501) is connected to a RAP pretreatment system (1). The RAP pretreatment system (1) includes a RAP silo (101). The discharge end of the RAP silo (101) is connected to a sealed conveying device (103). The air inlet (105) of the sealed conveying device (103) is connected to an ozone generator (104). The air outlet (106) of the sealed conveying device (103) is connected to the air inlet side of the first catalyst bed (201) of the carbon dioxide supply system (2). The air outlet side of the first catalyst bed (201) is connected to the air inlet side of the second catalyst bed (202). The air outlet side of the second catalyst bed (202) is connected to... The inlet (105) of the carbon dioxide storage tank (203) is connected to the feed end of the first-stage mixing cylinder (501), which is also connected to the new material supply system (3) containing new aggregates and cement powder. The outlet of the first-stage mixing cylinder (501) is connected to the feed end of the second-stage mixing cylinder (503). The feed end of the second-stage mixing cylinder (503) is also connected to each pipeline of the new material supply system (4). The outlet of the second-stage mixing cylinder (503) is connected to the feed end of the CO2 curing channel (504). The inlet (105) of the CO2 curing channel (504) is connected to the carbon dioxide storage tank (203) of the carbon dioxide supply system (2). The exhaust outlet of the CO2 curing channel (504) is connected to the exhaust tank (205) of the carbon dioxide supply system (2). The outlet of the CO2 curing channel (504) is connected to the finished product discharge system (6).
2. The multifunctional emulsified asphalt cold recycling continuous mixing plant according to claim 1, characterized in that, A RAP metering belt scale (102) is installed between the RAP hopper (101) and the sealed conveying device (103).
3. The multifunctional emulsified asphalt cold recycling continuous mixing plant according to claim 1, characterized in that, The new material supply system (3) includes a new aggregate cold silo (301) and several powder silos (302). The discharge ends of the new aggregate cold silo (301) and the powder silos (302) are connected to the asphalt emulsification recycling system (5) through a new material output device (304).
4. The multifunctional emulsified asphalt cold recycling continuous mixing plant according to claim 3, characterized in that, A new material metering belt scale (303) is installed between the new aggregate cold silo (301) and the powder silo (302) and the new material output device (304).
5. The multifunctional emulsified asphalt cold recycling continuous mixing plant according to claim 1, characterized in that, The new material supply system (4) includes an emulsified asphalt storage tank (401), a water tank (403), and an additive tank (405). The outlet of the emulsified asphalt storage tank (401) is connected to the secondary mixing tank (503) through an asphalt pump (402) and pipeline. The outlet of the water tank (403) is connected to the secondary mixing tank (503) through a water pump (404) and pipeline. The additive tank (405) stores regenerator and reinforcing agent, and its outlet is connected to the secondary mixing tank (503) through a metering pump (406) and pipeline.
6. The multifunctional emulsified asphalt cold recycling continuous mixing plant according to claim 5, characterized in that, The water tank (403) is equipped with a level gauge and an automatic water replenishment device.
7. The multifunctional emulsified asphalt cold recycling continuous mixing plant according to claim 1, characterized in that, The first catalyst bed (201) adopts MnO2 / γ-A l2 The O3 catalyst bed is used to decompose ozone, and the second catalyst bed (202) uses an activated carbon adsorption bed to absorb impurity gases.
8. The multifunctional emulsified asphalt cold recycling continuous mixing plant according to claim 1, characterized in that, The finished product discharge system (6) includes a discharge bin (602). The feed end of the discharge bin (602) is connected to the discharge end of the CO2 curing channel (504) through the finished product conveyor belt (601). A discharge gate (603) is provided at the bottom of the discharge bin (602).