Preparation method of modified asphalt based on rubber particles prepared from waste tires

Abstract

The invention relates to the technical field of modified asphalt, and discloses a preparation method of modified asphalt based on rubber particles prepared from waste tires, which comprises the following preparation steps: 1) adding an alkaline buffer solution and methanol into a container, and adding micron-sized particles, a composite deodorant, an emulsifier and a stabilizer; 2) stirring and mixing in the container by using a stirring structure to form a mixed solution; and 3) cooling the mixed solution to room temperature to form an emulsion, and freeze-drying the emulsion in a plastic cup to form the rubber particles. 4) heating the asphalt to a set temperature, adding the asphalt and the rubber particles into the stirring drum, and stirring and mixing to form modified asphalt; according to the preparation method, the performance of the modified asphalt is improved, meanwhile, efficient recycling of the waste tires is achieved, and important economic, social and environmental benefits are achieved.

Description

Technical Field

[0001] The patent of this invention relates to the technical field of modified asphalt, specifically, to a method for preparing modified asphalt based on rubber particles made from waste tires. Background Art

[0002] Academic research in related fields has shown that by scientifically and rationally treating waste tires, applying them to the single modification process of asphalt, and further implementing a composite modification strategy based on the advanced concept of "synergy", the road performance of rubber-modified asphalt can be significantly improved.

[0003] Modified asphalt is an important road construction material. Traditionally, its performance is improved by adding polymers, resins and other materials. However, with the increase in traffic volume and the increasingly complex road conditions, the performance of existing modified asphalt has been increasingly unable to meet the requirements.

[0004] In existing technologies, traditional modified asphalt is prone to softening and flowing under high temperature conditions, leading to road deformation and rutting. This not only affects road smoothness and driving comfort, but may also cause traffic accidents.

[0005] Under low temperature conditions, the brittleness of modified asphalt increases, and cracks are prone to form. These cracks will gradually expand over time, leading to water intrusion and further damage to the road structure. Especially in cold regions, the damage to roads caused by low temperatures in winter is particularly significant. The lack of low-temperature crack resistance of traditional modified asphalt has become a major factor restricting its widespread application.

[0006] In addition, when the road surface is eroded by rainwater, the adhesion of traditional modified asphalt will decrease, resulting in separation between the asphalt and the aggregate. This phenomenon is particularly common in rainy areas. It not only reduces the road's anti-skid performance, but may also cause early damage to the road surface. Moreover, in the long-term use process, the performance and durability of traditional modified asphalt gradually decline under the combined effects of multiple factors such as ultraviolet rays, oxidation, and temperature changes, requiring more frequent maintenance of the road, which increases the cost of road construction. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for preparing modified asphalt based on rubber particles made from waste tires, aiming to solve the problem of insufficient performance of modified asphalt in the prior art.

[0008] The present invention is achieved by a method for preparing modified asphalt based on rubber particles made from waste tires, comprising the following preparation steps:

[0009] 1) adding alkaline buffer and methanol into a container, heating the container to a set temperature, and then adding micron-sized particles, a composite deodorant, an emulsifier, and a stabilizer into the container, wherein the micron-sized particles are prepared from waste tires;

[0010] 2) Using a stirring structure to stir and mix the alkaline buffer solution, methanol, micron-sized particles, compound deodorant, emulsifier, and stabilizer in the container to form a mixed solution;

[0011] 3) After the mixed solution is cooled to room temperature, an emulsion is formed, and the emulsion is placed in a plastic cup for freeze drying. After the temperature of the emulsion cold trap reaches the set temperature, the emulsion forms rubber particles;

[0012] 4) After the asphalt is heated to a set temperature, the asphalt and rubber particles are added into a mixing drum and stirred and mixed to form modified asphalt.

[0013] Furthermore, in the preparation step 4), 100 parts by weight of asphalt and 3 to 7 parts by weight of rubber particles are added to a mixing drum and stirred and mixed according to the weight ratio.

[0014] Furthermore, in the preparation step 4), after the asphalt is heated to above 160° C., the heated asphalt and rubber particles are added to a mixing drum for stirring and mixing.

[0015] Furthermore, in the preparation step 4), the mixing drum is placed on a rotating table, and the mixing drum has a stirring shaft. After the asphalt and rubber particles are placed in the mixing drum, the rotating table rotates, driving the mixing drum to rotate synchronously, and the stirring shaft rotates synchronously in the mixing drum, and the rotation speed of the stirring shaft is greater than 400 r / min.

[0016] Furthermore, in the preparation step 4), the mixing drum is horizontally arranged, and has a horizontally arranged stirring chamber in the mixing drum, and the stirring shaft extends along the length direction of the stirring chamber; the stirring shaft is provided with a plurality of movable drums that move along the length direction of the stirring shaft, and the outer periphery of the movable drum is provided with a plurality of stirring blades;

[0017] In the preparation step 4), after the asphalt and the rubber particles are placed in the stirring chamber, the rotating table rotates at a variable speed, driving the stirring drum to rotate synchronously; the stirring shaft rotates synchronously in the stirring chamber, driving the multiple moving drums to rotate synchronously, and the multiple blades on the moving drums rotate synchronously with the moving drums to stir and mix the asphalt and the rubber particles;

[0018] During the process of synchronous rotation of the moving drum and the stirring shaft, as the rotation speed of the rotating platform changes, the plurality of moving drums reciprocate along the length direction of the stirring shaft to change the stirring position of the blades on the moving drum.

[0019] Furthermore, in the preparation step 1), the preparation steps of the micron-sized particles are as follows:

[0020] 1.1) Use a crusher to crush waste tires into rubber fragments;

[0021] 1.2) Soaking the rubber fragments in a sodium hydroxide solution to form a soaking solution, and grinding the soaking solution in a grinder to form a grinding solution;

[0022] 1.3) Separating the grinding liquid into particles, and sieving the separated particles to form the micron-sized particles.

[0023] Furthermore, in the preparation step 1.1), impurities in the waste tires are separated during the process of the pulverizer crushing the waste tires into rubber fragments; in the preparation step 1.2), the rubber fragments are soaked in a 1 mol / L sodium hydroxide solution for more than 24 hours to form the soaking liquid, and the soaking liquid is placed in a grinder and ground for more than 40 minutes to form the grinding liquid.

[0024] Furthermore, in the preparation step 1), 100 parts by weight of alkaline buffer and 2 to 5 parts by weight of methanol are added to a container, and after the container is heated to a set temperature, 20 to 30 parts by weight of micron-sized particles, 5 to 10 parts by weight of a composite deodorant, 0.5 to 1 part by weight of an emulsifier, and 1 to 2 parts by weight of a stabilizer are added to the container; the emulsifier is sodium dodecylbenzenesulfonate, and the stabilizer is calcium chloride or magnesium chloride.

[0025] Furthermore, in the preparation step 1), after adding the alkaline buffer solution and methanol into a container, the container is heated to above 50° C., and then the micron-sized particles, the composite deodorant, the emulsifier, and the stabilizer are added into the container in sequence;

[0026] In the preparation step 2), the rotation speed of the stirring structure is between 400 and 600 r / min, and the stirring structure stirs and mixes the alkaline buffer solution, methanol, micron-sized particles, composite deodorant, emulsifier, and stabilizer in the container to form a mixed solution, and the mixed solution is allowed to react for more than 1 hour;

[0027] In the preparation step 3), when the mixed solution is allowed to react for more than 1 hour, the heating of the container is stopped, and the mixed solution is cooled to room temperature to form an emulsion; when the cold trap temperature of the emulsion reaches -10°C, the emulsion is vacuum freeze-dried to form rubber particles.

[0028] Furthermore, in the preparation step 1.3), the grinding liquid is placed in a rotating cylinder for particle separation; the rotating cylinder has a longitudinally arranged inner cavity, and the bottom of the rotating cylinder has a bottom plate, and the bottom plate seals the bottom of the rotating cylinder;

[0029] The lower part of the rotating drum has a water filtering section, and the outer periphery of the water filtering section has multiple internal water filtering holes; the upper part of the rotating drum has a closed section, the top of the water filtering section is connected to the closed section, and the closed section has a piston head that moves up and down;

[0030] The outer periphery of the water filtering section is covered with a flexible filter cloth layer, and the filter cloth layer has a plurality of external water filtering holes; the upper end of the filter cloth layer surrounds and is fixed to the outer periphery of the water filtering section, the lower end of the filter cloth layer surrounds and is fixed to the outer periphery of the water filtering section, and the middle portion of the filter cloth layer freely surrounds the outer periphery of the water filtering section and is arranged in a loose state;

[0031] In the preparation step 3), the grinding liquid is placed in the water filtration section, the rotating cylinder is continuously rotated, driving the grinding liquid to rotate centrifugally, and the piston head moves back and forth along the closed section to longitudinally squeeze the grinding liquid. The liquid in the grinding liquid passes through the internal water filtration holes and the external water filtration holes respectively and separates from the grinding liquid, so that the grinding liquid is subjected to particle separation.

[0032] Compared with the prior art, the method for preparing modified asphalt based on rubber particles made from waste tires provided by the present invention has the following advantages:

[0033] 1) The addition of micron-sized rubber particles made from waste tires enhances the flexibility, fatigue resistance, and durability of the modified asphalt, resulting in excellent high-temperature stability, low-temperature crack resistance, and water stability. This not only improves the overall performance of the modified asphalt, but also extends the service life of the road and reduces maintenance costs. In particular, the addition of rubber particles significantly improves the problems of existing modified asphalt, such as its tendency to soften and flow in high-temperature environments, its tendency to crack in low-temperature environments, and its lack of water stability, thereby better adapting to the needs of road use under different environmental conditions.

[0034] 2) Utilizing waste tires as a waste resource, and transforming them into high-performance rubber particles through scientific and rational processing technology, this achieves efficient resource recycling and has significant environmental and economic benefits. While improving the performance of modified asphalt, it also provides an effective solution for the sustainable treatment of waste tires, bringing positive impacts to society and the environment.

[0035] 3) The addition of a composite deodorizer during the preparation process not only improves the working environment but also meets environmental protection requirements. In actual production, the reduction of odor can reduce the impact on the health of operators and also reduce pollution to the surrounding environment. While meeting the performance improvement, it also takes into account the requirements of environmental protection and health, and has a broader application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic flow chart of a method for preparing modified asphalt based on rubber particles made from waste tires provided by the present invention;

[0037] Figure 2 It is a cross-sectional schematic diagram of the mixing drum provided by the present invention;

[0038] Figure 3 is a schematic cross-sectional view of the rotating drum provided by the present invention;

[0039] Figure 4 Schematic diagram of particle size tested by the laser particle size analyzer provided by the present invention;

[0040] In the figure: mixing drum 100, mixing chamber 101, mixing shaft 102, moving drum 103, mixing blade 104, rotating table 105, rotating drum 200, inner chamber 201, bottom plate 202, water filtering section 203, closing section 204, piston head 205, filter cloth layer 206. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0042] The implementation of the present invention is described in detail below with reference to specific embodiments.

[0043] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0044] Reference Figure 1-4 The figure shows a preferred embodiment of the present invention.

[0045] The method for preparing modified asphalt based on rubber particles made from waste tires includes the following preparation steps:

[0046] 1) Adding alkaline buffer solution and methanol into a container, heating the container to a set temperature, and then adding micron-sized particles, a composite deodorant, an emulsifier, and a stabilizer into the container, wherein the micron-sized particles are prepared from waste tires;

[0047] 2) Using a stirring structure to stir and mix the alkaline buffer solution, methanol, micron-sized particles, compound deodorant, emulsifier, and stabilizer in the container to form a mixed solution;

[0048] 3) After the mixed liquid is cooled to room temperature, an emulsion is formed, and the emulsion is placed in a plastic cup for freeze drying. After the temperature of the emulsion cold trap reaches the set temperature, the emulsion forms rubber particles;

[0049] 4) After the asphalt is heated to a set temperature, the asphalt and rubber particles are added into the mixing drum 100 and stirred and mixed to form modified asphalt.

[0050] The above-mentioned method for preparing modified asphalt based on rubber particles made from waste tires has the following advantages:

[0051] 1) The addition of micron-sized rubber particles made from waste tires enhances the flexibility, fatigue resistance, and durability of the modified asphalt, resulting in excellent high-temperature stability, low-temperature crack resistance, and water stability. This not only improves the overall performance of the modified asphalt, but also extends the service life of the road and reduces maintenance costs. In particular, the addition of rubber particles significantly improves the problems of existing modified asphalt, such as its tendency to soften and flow in high-temperature environments, its tendency to crack in low-temperature environments, and its lack of water stability, thereby better adapting to the needs of road use under different environmental conditions.

[0052] 2) Utilizing waste tires as a waste resource, and transforming them into high-performance rubber particles through scientific and rational processing technology, this achieves efficient resource recycling and has significant environmental and economic benefits. While improving the performance of modified asphalt, it also provides an effective solution for the sustainable treatment of waste tires, bringing positive impacts to society and the environment.

[0053] 3) The addition of a composite deodorizer during the preparation process not only improves the working environment but also meets environmental protection requirements. In actual production, the reduction of odor can reduce the impact on the health of operators and also reduce pollution to the surrounding environment. While meeting the performance improvement, it also takes into account the requirements of environmental protection and health, and has a broader application prospect.

[0054] In this embodiment, in the preparation step 4), 100 parts by weight of asphalt and 3 to 7 parts by weight of rubber particles are added to the mixing drum 100 and stirred and mixed.

[0055] Through precise proportioning, the rubber particles are evenly dispersed in the asphalt, allowing the rubber particles and asphalt to fully blend to form modified asphalt with excellent performance. The addition of rubber particles gives the modified asphalt better flexibility and fatigue resistance, allowing it to effectively resist deformation and cracking when facing various stresses during road use, thereby extending the service life of the road.

[0056] In this embodiment, in the preparation step 4), after the asphalt is heated to a temperature higher than 160° C., the heated asphalt and the rubber particles are added to the mixing drum 100 for stirring and mixing.

[0057] In this way, at high temperatures, rubber particles can be better dispersed in the asphalt and fully integrated with the asphalt to form a uniform modified asphalt. This temperature helps to fully exert the modification effect of rubber particles, further improve the performance of modified asphalt, and make it perform well in high-temperature stability.

[0058] In this embodiment, in the preparation step 4), the mixing drum 100 is placed on a rotating table 105, and the mixing drum 100 has a stirring shaft 102. After the asphalt and the rubber particles are placed in the mixing drum 100, the rotating table 105 rotates, driving the mixing drum 100 to rotate synchronously, and the stirring shaft 102 rotates synchronously in the mixing drum 100, and the rotation speed of the stirring shaft 102 is greater than 400 r / min.

[0059] The high-speed rotation of the stirring shaft 102 can ensure that the rubber particles are evenly distributed in the asphalt, thereby preventing the agglomeration and uneven distribution of the rubber particles, thereby improving the quality and performance stability of the modified asphalt.

[0060] In this embodiment, in preparation step 4), the mixing drum 100 is arranged horizontally, and has a horizontally arranged stirring chamber 101 therein, and a stirring shaft 102 is arranged to extend along the length direction of the stirring chamber 101; a plurality of movable drums 103 are sleeved on the stirring shaft 102 and move along the length direction of the stirring shaft 102, and a plurality of stirring blades 104 are provided on the outer periphery of the movable drum 103;

[0061] In preparation step 4), after the asphalt and rubber particles are placed in the stirring chamber 101, the rotating table 105 rotates at a variable speed, driving the stirring drum 100 to rotate synchronously. The stirring shaft 102 rotates synchronously in the stirring chamber 101, driving the multiple moving drums 103 to rotate synchronously. The multiple blades on the moving drums 103 rotate synchronously with the moving drums 103 to stir and mix the asphalt and rubber particles.

[0062] As the moving cylinders 103 rotate synchronously with the stirring shaft 102 , as the rotation speed of the rotating platform 105 changes, the multiple moving cylinders 103 reciprocate along the length direction of the stirring shaft 102 to change the stirring position of the blades on the moving cylinders 103 .

[0063] Through the structural setting of the mixing drum 100, all-round and multi-level mixing of asphalt and rubber particles is achieved, and the reciprocating movement of the moving drum 103 enables the mixing blades 104 to cover different areas within the mixing chamber 101, further improving the uniformity and efficiency of the mixing, making the rubber particles more evenly dispersed in the asphalt, and enhancing the performance of the modified asphalt.

[0064] In this embodiment, in the preparation step 1), the preparation steps of micron-sized particles are as follows:

[0065] 1.1) Use a crusher to crush waste tires into rubber fragments;

[0066] 1.2) Soak the rubber fragments in a sodium hydroxide solution to form a soaking liquid, and grind the soaking liquid in a grinder to form a grinding liquid;

[0067] 1.3) The grinding liquid is subjected to particle separation, and the separated particles are sieved to form micron-sized particles.

[0068] Through the steps of crushing, soaking, grinding and particle separation, the particle size of the rubber particles is ensured to be uniform and small, and the activity and compatibility of the rubber particles are improved. Among them, the addition of micron-sized particles can significantly improve the performance of the modified asphalt, making it excel in aspects such as water stability. At the same time, it also provides an effective way for the efficient recycling of waste tires.

[0069] In this embodiment, in the preparation step 1.1), impurities in the waste tires are separated during the process of crushing the waste tires into rubber fragments by a pulverizer; in the preparation step 1.2), the rubber fragments are soaked in a 1 mol / L sodium hydroxide solution for more than 24 hours to form a soaking liquid, and the soaking liquid is placed in a grinder and ground for more than 40 minutes to form a grinding liquid.

[0070] Impurities are first separated during the crushing process to ensure the purity of the rubber fragments, providing a good foundation for subsequent processing. The soaking treatment with sodium hydroxide solution can activate the rubber fragments and improve their compatibility with asphalt. The extended grinding time ensures that the particle size of the rubber particles reaches the micron level, laying the foundation for improving the performance of the modified asphalt and making the modified asphalt perform well in terms of durability and other aspects.

[0071] In this embodiment, in the preparation step 1), 100 parts by weight of an alkaline buffer solution and 2 to 5 parts by weight of methanol are added to a container, and after the container is heated to a set temperature, 20 to 30 parts by weight of micron-sized particles, 5 to 10 parts by weight of a composite deodorant, 0.5 to 1 part by weight of an emulsifier, and 1 to 2 parts by weight of a stabilizer are added to the container; the emulsifier is sodium dodecylbenzenesulfonate, and the stabilizer is calcium chloride or magnesium chloride.

[0072] The addition of alkaline buffer and methanol provides a suitable environment for the processing of micron-sized particles, which helps to improve the dispersibility and stability of the particles. The addition of a composite deodorizer can effectively reduce the odor generated during the preparation process and improve the working environment. Among them, the use of sodium dodecylbenzenesulfonate and calcium chloride or magnesium chloride can further improve the dispersion effect and stability of micron-sized particles in the subsequent preparation process, making their performance in all aspects more balanced.

[0073] In this embodiment, in preparation step 1), after adding alkaline buffer and methanol to a container, the container is heated to above 50° C., and then the micron-sized particles, the composite deodorant, the emulsifier, and the stabilizer are added to the container in sequence;

[0074] In preparation step 2), the stirring mechanism rotates at a speed of 400 to 600 rpm, stirring and mixing the alkaline buffer solution, methanol, micron-sized particles, composite deodorant, emulsifier, and stabilizer in the container to form a mixed solution, and then allowing the mixed solution to react for at least 1 hour.

[0075] In the preparation step 3), when the mixed solution is allowed to react for more than 1 hour, the heating of the container is stopped, and the mixed solution is cooled to room temperature to form an emulsion; when the emulsion cold trap temperature reaches -10°C, the emulsion is vacuum freeze-dried to form rubber particles.

[0076] By controlling the heating temperature, stirring speed, and static reaction time, it is possible to ensure that all components are fully mixed and reacted to form a stable emulsion. The vacuum freeze-drying treatment method can quickly remove water from the emulsion to form rubber particles with uniform particle size and stable performance. These control measures optimize the preparation process of rubber particles, enabling them to be better mixed with asphalt, so that the modified asphalt performs well in terms of high-temperature stability, low-temperature crack resistance, water stability, and durability.

[0077] In this embodiment, in the preparation step 1.3), the grinding liquid is placed in a rotating drum 200 for particle separation; the rotating drum 200 has a longitudinally arranged inner cavity 201, and the bottom of the rotating drum 200 has a bottom plate 202, which seals the bottom of the rotating drum 200;

[0078] The lower portion of the rotating drum 200 has a water filtering section 203 with a plurality of internal water filtering holes on its periphery. The upper portion of the rotating drum 200 has a closed section 204. The top of the water filtering section 203 is connected to the closed section 204. The closed section 204 has a piston head 205 that reciprocates up and down.

[0079] The outer periphery of the water filtering section 203 is covered with a flexible filter cloth layer 206 having a plurality of external water filtering holes. The upper end of the filter cloth layer 206 surrounds and is fixed to the outer periphery of the water filtering section 203, while the lower end of the filter cloth layer 206 surrounds and is fixed to the outer periphery of the water filtering section 203. The middle portion of the filter cloth layer 206 freely surrounds and is arranged in a loose manner around the outer periphery of the water filtering section 203.

[0080] In preparation step 3), the grinding liquid is placed in the water filtration section 203, the rotating cylinder 200 rotates continuously, driving the grinding liquid to rotate centrifugally, and the piston head 205 moves back and forth along the closed section 204, longitudinally squeezing the grinding liquid. The liquid in the grinding liquid passes through the internal water filtration holes and the external water filtration holes respectively, and separates from the grinding liquid, so that the grinding liquid is separated into particles.

[0081] The centrifugal force generated by the continuous rotation of the rotating drum 200 and the longitudinal extrusion generated by the up and down reciprocating movement of the piston head 205 can enable the liquid to be quickly and fully separated from the grinding liquid. At the same time, the flexibility and loose arrangement of the filter cloth layer 206 can effectively prevent particles from clogging the water filter holes, ensuring the smooth progress of the separation process. In this way, the separated particles have uniform particle size and high purity, providing high-quality micron-level particles for the subsequent preparation of modified asphalt, further improving the performance of the modified asphalt.

[0082] The following will be combined with the embodiments of the present invention to provide a specific, clear, and complete description of the technical solutions in the embodiments of the present invention, so that the content of the method for preparing modified asphalt based on rubber particles made from waste tires is easier to understand:

[0083] The waste tires are fed into a crusher, which uses strong mechanical force to crush the tires into small fragments, about 3 to 5 cm in length, separating metals (such as steel wire) and other impurities (such as fiber, glass and nylon) from the rubber to obtain rubber fragments.

[0084] After soaking the rubber fragments in 1 mol / L sodium hydroxide solution for 24 hours, the fragments and the solution were placed in the grinding tank of a planetary grinder, and hard rough alloy balls were added as grinding media with a gradation of 5mm:3mm:1mm:0.5mm:0.1mm and a ratio of 1:3:3:5:5. The grinding was carried out for 40 minutes. After completion, the particles were separated and sieved to obtain micron-sized particles.

[0085] 100 parts by weight of alkaline buffer solution and 2 to 5 parts by weight of methanol are added to a container and heated to 50° C., 20 to 30 parts by weight of rubber microparticles and 5 to 10 parts by weight of a composite deodorant are added, and then 0.5 to 1 part by weight of an emulsifier, sodium dodecylbenzenesulfonate, and 1 to 2 parts by weight of a stabilizer are added dropwise. The stirring mechanism is turned on and the speed is set to 400 to 600 r / min. The reaction is carried out for 1 hour, and the heating is stopped. After cooling to room temperature, the emulsion is taken out and placed in a plastic cup for freeze drying. The mixture is pre-cooled for 30 minutes. When the cold trap temperature reaches below -10° C., vacuum freeze drying is performed to obtain rubber microparticles.

[0086] The modified asphalt preparation method based on rubber microparticles made from waste tires first successfully produces micron-sized rubber microparticles by using a sodium hydroxide solution combined with a grinding technique. This process effectively regulates the charge characteristics and functional group composition of the rubber microparticles' surfaces, inducing a series of chemical transformations, including hydrolysis reactions, to generate oxygen-containing functional groups such as hydroxyl groups. This provides a basis for chemical bonding between the rubber microparticles and the ammonium phosphomolybdate and nano-calcium carbonate components of the composite deodorant. Furthermore, the sodium hydroxide solution acts as a surface treatment agent, stripping away the zinc stearate coating or other contaminants on the rubber particle surface, resulting in a rougher surface and optimizing the efficiency of the grinding process.

[0087] Secondly, emulsion polymerization technology is used to synthesize rubber microparticles. The raw materials selected are highly safe, low in energy consumption, and environmentally friendly. The polymerization process is easy to control, making it easy to obtain rubber microspheres with excellent performance. Furthermore, by effectively compounding these rubber microparticles with the composite deodorant, sufficient contact between the two is promoted, thereby significantly enhancing its deodorization and smoke suppression performance.

[0088] Finally, the rubber particles involved do not need to rely on high-speed shearing technology when incorporating them into asphalt and achieving uniform dispersion. Instead, they can be completed using hot melt stirring technology. Compared with the traditional rubber particle dispersion method using high-speed shearing technology, the use of these particles significantly reduces energy consumption in the production process.

[0089] The alkaline buffer solution is a carbonate buffer solution, specifically a sodium carbonate and sodium bicarbonate solution, with a pH value of 9.6.

[0090] The composite deodorant is a mixture of ammonium phosphomolybdate and nano calcium carbonate in a ratio of 1:1.

[0091] Wherein, the emulsifier is sodium dodecylbenzenesulfonate;

[0092] Wherein, the stabilizer is one of calcium chloride or magnesium chloride.

[0093] The following is the preparation process of the modified asphalt mentioned in the present invention:

[0094] After heating 100 parts by weight of asphalt to 160° C., add 3 to 7 parts by weight of rubber particles, start the stirring mechanism, set the speed to 400 r / min, and stir for 15 minutes to finally obtain modified asphalt.

[0095] Among them, the asphalt is one of No. 30, No. 50, and No. 70 asphalt.

[0096] Hereinafter, the technical solutions in the embodiments of the present invention will be described in detail, clearly and completely in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0097] Example 1:

[0098] (1) The tire is fed into a crusher, which uses strong mechanical force to crush the tire into small fragments, about 3 to 5 cm in length, separating metal (such as steel wire) and other impurities (such as fiber, glass and nylon) from the rubber to obtain rubber fragments;

[0099] (2) After soaking the rubber fragments in 1 mol / L sodium hydroxide solution for 24 h, the fragments and the solution were placed in the grinding tank of a planetary grinder, and hard rough alloy balls were added as grinding media with a gradation of 5 mm: 3 mm: 1 mm: 0.5 mm: 0.1 mm and a ratio of 1: 3: 3: 5: 5. The grinding was carried out for 40 minutes. After completion, the particles were separated and sieved to obtain micron-sized particles.

[0100] (3) Add 100 parts by weight of alkaline buffer solution and 3 parts by weight of methanol into a container, heat to 50°C, add 25 parts by weight of rubber particles and 5 parts by weight of a composite deodorant, then dropwise add 1 part by weight of an emulsifier, sodium dodecylbenzenesulfonate, and 2 parts by weight of a stabilizer, start the stirring mechanism, set the speed to 500 r / min, react for 1 hour, stop heating, cool to room temperature, take the emulsion and put it into a plastic cup for freeze drying, pre-cool for 30 minutes, and when the cold trap temperature reaches below -10°C, perform vacuum freeze drying to obtain rubber particles;

[0101] (4) After heating 100 parts by weight of No. 70 asphalt to 160°C, add 3 parts by weight of rubber particles, start the stirring mechanism, set the speed to 400 r / min, and stir for 15 minutes to finally obtain modified asphalt.

[0102] Example 2:

[0103] (1) The tire is fed into a crusher, which uses strong mechanical force to crush the tire into small fragments, about 3 to 5 cm in length, separating metal (such as steel wire) and other impurities (such as fiber, glass and nylon) from the rubber to obtain rubber fragments;

[0104] (2) After soaking the rubber fragments in 1 mol / L sodium hydroxide solution for 24 h, the fragments and the solution were placed in the grinding tank of a planetary grinder, and hard rough alloy balls were added as grinding media with a gradation of 5 mm: 3 mm: 1 mm: 0.5 mm: 0.1 mm and a ratio of 1: 3: 3: 5: 5. The grinding was carried out for 40 minutes. After completion, the particles were separated and sieved to obtain micron-sized particles.

[0105] (3) Add 100 parts by weight of alkaline buffer solution and 3 parts by weight of methanol into a container, heat to 50°C, add 25 parts by weight of rubber particles and 5 parts by weight of a composite deodorant, then dropwise add 1 part by weight of an emulsifier, sodium dodecylbenzenesulfonate, and 2 parts by weight of a stabilizer, start the stirring mechanism, set the speed to 500 r / min, react for 1 hour, stop heating, cool to room temperature, take the emulsion and put it into a plastic cup for freeze drying, pre-cool for 30 minutes, and when the cold trap temperature reaches below -10°C, perform vacuum freeze drying to obtain rubber particles;

[0106] (4) After heating 100 parts by weight of No. 70 asphalt to 160°C, add 5 parts by weight of rubber particles, start the stirring mechanism, set the speed to 400 r / min, and stir for 15 minutes to finally obtain modified asphalt.

[0107] Example 3:

[0108] (1) The tire is fed into a crusher, which uses strong mechanical force to crush the tire into small fragments, about 3 to 5 cm in length, separating metal (such as steel wire) and other impurities (such as fiber, glass and nylon) from the rubber to obtain rubber fragments;

[0109] (2) After soaking the rubber fragments in 1 mol / L sodium hydroxide solution for 24 h, the fragments and the solution were placed in the grinding tank of a planetary grinder, and hard rough alloy balls were added as grinding media with a gradation of 5 mm: 3 mm: 1 mm: 0.5 mm: 0.1 mm and a ratio of 1: 3: 3: 5: 5. The grinding was carried out for 40 minutes. After completion, the particles were separated and sieved to obtain micron-sized particles.

[0110] (3) Add 100 parts by weight of alkaline buffer solution and 3 parts by weight of methanol into a container, heat to 50°C, add 25 parts by weight of rubber particles and 5 parts by weight of a composite deodorant, then dropwise add 1 part by weight of an emulsifier, sodium dodecylbenzenesulfonate, and 2 parts by weight of a stabilizer, start the stirring mechanism, set the speed to 500 r / min, react for 1 hour, stop heating, cool to room temperature, take the emulsion and put it into a plastic cup for freeze drying, pre-cool for 30 minutes, and when the cold trap temperature reaches below -10°C, perform vacuum freeze drying to obtain rubber particles;

[0111] (4) After heating 100 parts by weight of No. 70 asphalt to 160°C, add 7 parts by weight of rubber particles, start the stirring mechanism, set the speed to 400 r / min, and stir for 15 minutes to finally obtain modified asphalt.

[0112] Example 4:

[0113] (1) The tire is fed into a crusher, which uses strong mechanical force to crush the tire into small fragments, about 3 to 5 cm in length, separating metal (such as steel wire) and other impurities (such as fiber, glass and nylon) from the rubber to obtain rubber fragments;

[0114] (2) After soaking the rubber fragments in 1 mol / L sodium hydroxide solution for 24 h, the fragments and the solution were placed in the grinding tank of a planetary grinder, and hard rough alloy balls were added as grinding media with a gradation of 5 mm: 3 mm: 1 mm: 0.5 mm: 0.1 mm and a ratio of 1: 3: 3: 5: 5. The grinding was carried out for 40 minutes. After completion, the particles were separated and sieved to obtain micron-sized particles.

[0115] (3) Add 100 parts by weight of alkaline buffer solution and 3 parts by weight of methanol into a container, heat to 50°C, add 25 parts by weight of rubber particles and 7 parts by weight of a composite deodorant, then dropwise add 1 part by weight of an emulsifier, sodium dodecylbenzenesulfonate, and 2 parts by weight of a stabilizer, start the stirring mechanism, set the speed to 500 r / min, react for 1 hour, stop heating, cool to room temperature, take the emulsion and put it into a plastic cup for freeze drying, pre-cool for 30 minutes, and when the cold trap temperature reaches below -10°C, perform vacuum freeze drying to obtain rubber particles;

[0116] (4) After heating 100 parts by weight of No. 70 asphalt to 160°C, add 5 parts by weight of rubber particles, start the stirring mechanism, set the speed to 400 r / min, and stir for 15 minutes to finally obtain modified asphalt.

[0117] Example 5:

[0118] (1) The tire is fed into a crusher, which uses strong mechanical force to crush the tire into small fragments, about 3 to 5 cm in length, separating metal (such as steel wire) and other impurities (such as fiber, glass and nylon) from the rubber to obtain rubber fragments;

[0119] (2) After soaking the rubber fragments in 1 mol / L sodium hydroxide solution for 24 h, the fragments and the solution were placed in the grinding tank of a planetary grinder, and hard rough alloy balls were added as grinding media with a gradation of 5 mm: 3 mm: 1 mm: 0.5 mm: 0.1 mm and a ratio of 1: 3: 3: 5: 5. The grinding was carried out for 40 minutes. After completion, the particles were separated and sieved to obtain micron-sized particles.

[0120] (3) Add 100 parts by weight of alkaline buffer solution and 3 parts by weight of methanol into a container, heat to 50°C, add 25 parts by weight of rubber particles and 10 parts by weight of a composite deodorant, and then dropwise add 1 part by weight of an emulsifier, sodium dodecylbenzenesulfonate, and 2 parts by weight of a stabilizer; start the stirring mechanism, set the speed to 500 r / min, and react for 1 hour; stop heating, cool to room temperature, take the emulsion and put it into a plastic cup for freeze drying, pre-cool for 30 minutes, and when the cold trap temperature reaches below -10°C, perform vacuum freeze drying to obtain rubber particles;

[0121] (4) After heating 100 parts by weight of No. 70 asphalt to 160°C, add 5 parts by weight of rubber particles, start the stirring mechanism, set the speed to 400 r / min, and stir for 15 minutes to finally obtain modified asphalt.

[0122] Comparative Example 1 (based on Example 2, without adding the composite deodorant)

[0123] (1) The tire is fed into a crusher, which uses strong mechanical force to crush the tire into small fragments, about 3 to 5 cm in length, separating metal (such as steel wire) and other impurities (such as fiber, glass and nylon) from the rubber to obtain rubber fragments;

[0124] (2) After soaking the rubber fragments in 1 mol / L sodium hydroxide solution for 24 h, the fragments and the solution were placed in the grinding tank of a planetary grinder, and hard rough alloy balls were added as grinding media with a gradation of 5 mm: 3 mm: 1 mm: 0.5 mm: 0.1 mm and a ratio of 1: 3: 3: 5: 5. The grinding was carried out for 40 minutes. After completion, the particles were separated and sieved to obtain micron-sized particles.

[0125] (3) After heating 100 parts by weight of No. 70 asphalt to 160°C, add 5 parts by weight of rubber particles, start the stirring mechanism, set the speed to 400 r / min, and stir for 15 minutes to finally obtain modified asphalt.

[0126] Comparative Example 2 (based on Example 2, without emulsion polymerization)

[0127] (1) The tire is fed into a crusher, which uses strong mechanical force to crush the tire into small fragments, about 3 to 5 cm in length, separating metal (such as steel wire) and other impurities (such as fiber, glass and nylon) from the rubber to obtain rubber fragments;

[0128] (2) After soaking the rubber fragments in 1 mol / L sodium hydroxide solution for 24 h, the fragments and the solution were placed in the grinding tank of a planetary grinder, and hard rough alloy balls were added as grinding media with a gradation of 5 mm: 3 mm: 1 mm: 0.5 mm: 0.1 mm and a ratio of 1: 3: 3: 5: 5. The grinding was carried out for 40 minutes. After completion, the particles were separated and sieved to obtain micron-sized particles.

[0129] (3) After heating 100 parts by weight of No. 70 asphalt to 160°C, add 5 parts by weight of rubber particles and 2 parts by weight of composite deodorizer, start the stirring mechanism, set the speed to 400 r / min, and stir for 15 minutes to finally obtain modified asphalt.

[0130] The above five embodiments are carried out by the following steps:

[0131] (1) Use a laser particle size analyzer to measure the particle size of the rubber particles and micron-sized particles in Example 2. Figure 4Analysis clearly shows that the average particle size of the rubber microparticles increases compared to micron-sized particles, and the variance of the particle size distribution decreases significantly, indicating a significant improvement in particle size consistency. This phenomenon can be attributed to the effective bonding of the rubber microparticles with the ammonium phosphomolybdate and nano-calcium carbonate in the composite deodorant during the preparation process. This bonding not only promotes particle size growth but also reduces the discreteness of the particle size distribution by optimizing the chemical and physical properties of the particle surface, thereby achieving a more uniform particle size distribution.

[0132] (2) Test the penetration, ductility and softening point of asphalt according to JTG·E20-2011 “Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering”.

[0133] Needle penetration test: Test according to the relevant specifications in T·0604-2011;

[0134] Ductility test: Tested according to the relevant specifications in T·0605-2011;

[0135] Softening point test: Test according to the relevant specifications in T·0606-2011;

[0136] The results are shown in the following table:

[0137]

[0138] Compared to No. 70 asphalt, the needle penetration of Comparative Example 1 decreased by 16.4%, while the ductility and softening point increased by 35.5% and 54.9%, respectively. This indicates that the rubber microparticles significantly improved the high-temperature performance of asphalt. Compared to Comparative Example 1, the three major indicators of Example 2 showed little change, indicating that the composite deodorizer had little impact on asphalt performance.

[0139] (3) The deodorizing effect of asphalt was tested according to DB32 / T·4650-2024 "General Technical Specifications for Environmentally Friendly Deodorizing Asphalt". The results are shown in the following table:

[0140]

[0141]

[0142] In the table, V is the corresponding average value of gas content test, and its expression is:

[0143]

[0144] Where V 3min +V 3.5min +......+V 26.5min +V 27min The sum of the test gas content values tested between 3 minutes and 27 minutes.

[0145] P represents the percentage reduction of the corresponding gas content compared to Comparative Example 1, and its expression is:

[0146]

[0147] According to the above test results, compared with Comparative Example 1 (based on Example 2, without adding the composite deodorant), Examples 1-5 have significantly reduced the emission content of H2S, NO, and VOC, among which Example 5 has the best effect. Compared with Comparative Example 2 (based on Example 2, without emulsion polymerization), Example 2 has improved the percentage reduction of the gas content of H2S, NO, and VOC, which shows that the emulsion polymerization method used in this invention patent can enhance the deodorizing and smoke suppression efficiency of the deodorant.

[0148] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing modified asphalt based on rubber particles made from waste tires, characterized in that: The method comprises the following preparation steps: 1) adding alkaline buffer and methanol into a container, heating the container to a set temperature, and then adding micron-sized particles, a composite deodorant, an emulsifier, and a stabilizer into the container, wherein the micron-sized particles are prepared from waste tires; 2) Using a stirring structure to stir and mix the alkaline buffer solution, methanol, micron-sized particles, compound deodorant, emulsifier, and stabilizer in the container to form a mixed solution; 3) After the mixed solution is cooled to room temperature, an emulsion is formed, and the emulsion is placed in a plastic cup for freeze drying. After the temperature of the emulsion cold trap reaches the set temperature, the emulsion forms rubber particles; 4) After the asphalt is heated to a set temperature, the asphalt and rubber particles are added into a mixing drum and stirred and mixed to form modified asphalt.

2. The method for preparing modified asphalt based on rubber particles made from waste tires according to claim 1, characterized in that: In the preparation step 4), 100 parts by weight of asphalt and 3 to 7 parts by weight of rubber particles are added to a mixing drum and stirred and mixed.

3. The method for preparing modified asphalt based on rubber particles made from waste tires according to claim 1, characterized in that: In the preparation step 4), the asphalt is heated to a temperature higher than 160° C., and the heated asphalt and rubber particles are added to a mixing drum for stirring and mixing.

4. The method for preparing modified asphalt based on rubber particles made from waste tires according to any one of claims 1 to 3, characterized in that: In the preparation step 4), the mixing drum is placed on a rotating table, and the mixing drum has a stirring shaft. After the asphalt and rubber particles are placed in the mixing drum, the rotating table rotates, driving the mixing drum to rotate synchronously, and the stirring shaft rotates synchronously in the mixing drum. The rotation speed of the stirring shaft is greater than 400 r / min.

5. The method for preparing modified asphalt based on rubber particles made from waste tires according to claim 4, characterized in that: In the preparation step 4), the mixing drum is horizontally arranged, and has a horizontally arranged stirring chamber therein, and the stirring shaft extends along the length direction of the stirring chamber; the stirring shaft is sleeved with a plurality of movable drums that move along the length direction of the stirring shaft, and the outer periphery of the movable drum is provided with a plurality of stirring blades; In the preparation step 4), after the asphalt and the rubber particles are placed in the stirring chamber, the rotating table rotates at a variable speed, driving the stirring drum to rotate synchronously; the stirring shaft rotates synchronously in the stirring chamber, driving the multiple moving drums to rotate synchronously, and the multiple blades on the moving drums rotate synchronously with the moving drums to stir and mix the asphalt and the rubber particles; During the process of synchronous rotation of the moving drum and the stirring shaft, as the rotation speed of the rotating platform changes, the plurality of moving drums reciprocate along the length direction of the stirring shaft to change the stirring position of the blades on the moving drum.

6. The method for preparing modified asphalt based on rubber particles made from waste tires according to any one of claims 1 to 3, characterized in that: In the preparation step 1), the preparation steps of the micron-sized particles are as follows: 1.1) Use a crusher to crush waste tires into rubber fragments; 1.2) Soaking the rubber fragments in a sodium hydroxide solution to form a soaking liquid, and grinding the soaking liquid in a grinder to form a grinding liquid; 1.3) Separating the grinding liquid into particles, and sieving the separated particles to form the micron-sized particles.

7. The method for preparing modified asphalt based on rubber particles made from waste tires according to claim 6, characterized in that: In the preparation step 1.1), during the process of the pulverizer pulverizing the waste tires into rubber fragments, impurities in the waste tires are separated; In the preparation step 1.2), the rubber fragments are soaked in a 1 mol / L sodium hydroxide solution for more than 24 hours to form the soaking solution, and the soaking solution is placed in a grinder and ground for more than 40 minutes to form the grinding liquid.

8. The method for preparing modified asphalt based on rubber particles made from waste tires according to any one of claims 1 to 3, characterized in that: In the preparation step 1), 100 parts by weight of an alkaline buffer solution and 2 to 5 parts by weight of methanol are added to a container, and after the container is heated to a set temperature, 20 to 30 parts by weight of micron-sized particles, 5 to 10 parts by weight of a composite deodorant, 0.5 to 1 part by weight of an emulsifier, and 1 to 2 parts by weight of a stabilizer are added to the container; the emulsifier is sodium dodecylbenzenesulfonate, and the stabilizer is calcium chloride or magnesium chloride.

9. The method for preparing modified asphalt based on rubber particles made from waste tires according to any one of claims 1 to 3, characterized in that: In the preparation step 1), after adding the alkaline buffer solution and methanol into a container, the container is heated to above 50° C., and then the micron-sized particles, the composite deodorant, the emulsifier, and the stabilizer are added into the container in sequence; In the preparation step 2), the rotation speed of the stirring structure is between 400 and 600 r / min, and the stirring structure stirs and mixes the alkaline buffer solution, methanol, micron-sized particles, composite deodorant, emulsifier, and stabilizer in the container to form a mixed solution, and the mixed solution is allowed to react for more than 1 hour; In the preparation step 3), when the mixed solution is allowed to react for more than 1 hour, the heating of the container is stopped, and the mixed solution is cooled to room temperature to form an emulsion; when the cold trap temperature of the emulsion reaches -10°C, the emulsion is vacuum freeze-dried to form rubber particles.

10. The method for preparing modified asphalt based on rubber particles made from waste tires according to claim 6, characterized in that: In the preparation step 1.3), the grinding liquid is placed in a rotating cylinder for particle separation; the rotating cylinder has a longitudinally arranged inner cavity, and the bottom of the rotating cylinder has a bottom plate, and the bottom plate seals the bottom of the rotating cylinder; The lower part of the rotating drum has a water filtering section, and the outer periphery of the water filtering section has multiple internal water filtering holes; the upper part of the rotating drum has a closed section, the top of the water filtering section is connected to the closed section, and the closed section has a piston head that moves up and down; The outer periphery of the water filtering section is covered with a flexible filter cloth layer, and the filter cloth layer has a plurality of external water filtering holes; the upper end of the filter cloth layer surrounds and is fixed to the outer periphery of the water filtering section, the lower end of the filter cloth layer surrounds and is fixed to the outer periphery of the water filtering section, and the middle portion of the filter cloth layer freely surrounds the outer periphery of the water filtering section and is arranged in a loose state; In the preparation step 3), the grinding liquid is placed in the water filtration section, the rotating cylinder is continuously rotated, driving the grinding liquid to rotate centrifugally, and the piston head moves back and forth along the closed section to longitudinally squeeze the grinding liquid. The liquid in the grinding liquid passes through the internal water filtration holes and the external water filtration holes respectively and separates from the grinding liquid, so that the grinding liquid is subjected to particle separation.

Images