Microwave-sensitive nickel slag composite asphalt pavement material and preparation method thereof

Abstract

The application discloses a microwave-sensitive nickel slag composite asphalt pavement material, which comprises the following components in percentage: 70%-80% of nickel slag aggregate, specifically including 40%-45% of nickel slag coarse aggregate and 30%-35% of nickel slag fine aggregate; 5%-6% of base asphalt; 5%-7% of wave-absorbing modifier; and 6%-7% of mineral powder. A microwave-sensitive nickel slag composite asphalt pavement material preparation method is used for preparing the microwave-sensitive nickel slag composite asphalt pavement material, and comprises the following steps: S1, preparing raw materials of each component according to a preset proportion; S2, pre-treating the nickel slag to obtain nickel slag coarse aggregate and nickel slag fine aggregate; S3, modifying the wave-absorbing agent, ultrasonically dispersing ferromagnetic powder and silane coupling agent in trichloroethylene, and obtaining surface functionalized wave-absorbing modifier after removing the solvent; S4, adding the nickel slag aggregate obtained in S2, the wave-absorbing agent obtained in S3 and the mineral powder into the heated base asphalt in sequence, and then performing high-speed shearing stirring to obtain a mixture; and S5, performing compression molding on the mixture obtained in S4, and controlling the void ratio to be 3%-6%.

Description

Technical Field

[0001] This invention belongs to the technical field of comprehensive utilization of metallurgical solid waste and road engineering materials, specifically relating to a microwave-sensitive nickel slag composite asphalt pavement material and its preparation method. Background Technology

[0002] In recent years, the global annual production of nickel slag has shown a year-on-year increasing trend, currently reaching tens of millions of tons. The large-scale generation of nickel slag has placed enormous pressure on the environment and resources. Nickel slag stockpiling not only occupies a large amount of land resources but also pollutes soil, water, and air. According to relevant research, the heavy metal content in the soil surrounding nickel slag stockpiling areas exceeds standards by several times, posing a potential threat to the ecological environment and human health. Faced with such a massive nickel slag production and serious stockpiling pollution problem, accelerating the resource utilization of nickel slag is imperative. The National Development and Reform Commission, the Ministry of Industry and Information Technology, and other departments issued the "Notice on Promoting the Agglomeration and Development of the Comprehensive Utilization Industry of Bulk Solid Waste" (2019), which clearly proposes to promote the large-scale and high-quality utilization of metallurgical slag (including nickel slag), encourages the extraction of useful metal components, and promotes low-energy-consumption, high-value-added technological pathways. Furthermore, the "Guiding Opinions on the Comprehensive Utilization of Bulk Solid Waste during the 14th Five-Year Plan Period" (2021) requires expanding the application of steel slag (including nickel slag) in concrete admixtures and exploring other large-scale utilization channels. Therefore, by preparing nickel slag into microwave road surface materials, etc., the effective recycling and reuse of resources can be achieved, reducing the negative impact on the environment.

[0003] Traditional methods of road de-icing and snow removal suffer from problems such as low efficiency, environmental pollution, and high cost.

[0004] Mechanical / Manual Snow Removal: While manual snow removal is a traditional method and offers high flexibility without requiring complex equipment, it suffers from significant drawbacks, including low efficiency, high cost, and prominent safety hazards during operation. De-icing Agents: Currently used chloride-based de-icing agents easily lead to soil salinization and vegetation damage, while also polluting groundwater. Microwave Heating Technology: Existing microwave snow removal devices suffer from insufficient penetration depth and low absorption efficiency. Furthermore, the road surface material itself has a weak microwave response, resulting in slow heating speed and high energy consumption. Nickel slag has a high iron content. After oxidation, the iron in the olivine phase can be converted into magnetite. The magnetic materials in the oxidized nickel slag can enhance the microwave absorption capacity of asphalt pavement. However, existing technologies use nickel slag containing heavy metals. The leaching rate of these heavy metals must be considered when preparing road materials to ensure no environmental pollution. Therefore, there is an urgent need to develop an asphalt pavement material that combines microwave sensitivity with road performance. Application content

[0005] The purpose of this application is to provide a microwave-sensitive nickel slag composite asphalt pavement material and its preparation method, the specific technical solution of which is as follows:

[0006] A microwave-sensitive nickel slag composite asphalt pavement material comprises the following components by percentage: 70%-80% nickel slag aggregate, specifically including 40%-45% coarse nickel slag aggregate and 30%-35% fine nickel slag aggregate; 5%-6% base asphalt; 5%-7% microwave-absorbing modifier; and 6%-7% mineral powder. The particle size of the coarse nickel slag aggregate is 2.36 mm–13.2 mm, and the particle size of the fine nickel slag aggregate is 0.075 mm–2.36 mm. The base asphalt is SBS-modified asphalt. The microwave-absorbing modifier is prepared by surface modification of ferromagnetic powder with a silane coupling agent, and the particle size range of the microwave-absorbing modifier is 1–50 μm.

[0007] A method for preparing microwave-sensitive nickel slag composite asphalt pavement material includes: S1, preparing raw materials of each component according to a preset ratio; S2, pretreating nickel slag to obtain nickel slag coarse aggregate and nickel slag fine aggregate; S3, modifying the microwave absorber by ultrasonically dispersing ferromagnetic powder and silane coupling agent in trichloroethylene, removing the solvent to obtain a surface-functionalized microwave absorber modifier; S4, heating the base asphalt and sequentially adding the nickel slag aggregate obtained in S2, the microwave absorber obtained in S3, and mineral powder, then high-speed shearing and stirring to obtain a mixture; S5, pressing the mixture obtained in S4 into shape, controlling the porosity to 3%-6%.

[0008] The pretreatment of nickel slag in S2 includes: S2.1, mixing nickel slag and calcium oxide in a preset ratio and then carrying out a high-temperature melting oxidation reaction; S2.2, cooling the nickel slag after the reaction in S2.1 and then performing a crushing process to collect nickel slag particles of different particle sizes; S2.3, removing impurities from the nickel slag particles collected in S2.2; S2.4, microwaving the nickel slag particles after removing impurities in S2.3, and then cooling them to obtain coarse nickel slag aggregate and fine nickel slag aggregate according to different particle size ranges.

[0009] The modification of the microwave absorbing agent in step S3 includes: S3.1, mixing Fe3O4 powder and KH550 silane coupling agent according to a preset ratio; S3.2, adding the Fe3O4 powder and KH550 silane coupling agent mixed in S3.1 to a trichloroethylene solution to obtain a mixed solution in which the trichloroethylene solution completely submerges the solid particles; S3.3, ultrasonically dispersing the mixed solution obtained in S3.2 to make the Fe3O4 powder more uniformly dispersed in the solution, thereby increasing the contact area between the Fe3O4 powder and the KH550 silane coupling agent; S3.4, drying the dispersed mixed solution in S3.3 and removing the trichloroethylene solution to finally obtain the microwave absorbing modifier.

[0010] The beneficial effects of this application are as follows: the design of this application increases the microwave heating rate by more than 60% (compared to ordinary asphalt), and can melt a 2cm thick ice layer within 10-15 minutes; it can save 30%-40% energy compared to traditional heating methods; nickel slag is recycled from industrial waste, which can realize the effective recycling and reuse of resources, reduce the negative impact on the environment, and reduce road infrastructure costs by 30%-40%; microwave treatment reduces high-temperature oxidation of asphalt, delays material aging, and meets the requirements of rutting resistance and durability in cold regions; it is compatible with existing asphalt paving equipment, without the need for additional equipment replacement; the microwave power is adjustable in real time, which facilitates automated construction. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the process for preparing microwave-sensitive nickel slag composite asphalt pavement material according to this application. Specific Implementation

[0012] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0013] A microwave-sensitive nickel slag composite asphalt pavement material comprises the following components by percentage: 70%-80% nickel slag aggregate, specifically including 40%-45% coarse nickel slag aggregate and 30%-35% fine nickel slag aggregate; 5%-6% base asphalt; 5%-7% microwave-absorbing modifier; and 6%-7% mineral powder. The particle size of the coarse nickel slag aggregate is 2.36mm-13.2mm, and the particle size of the fine nickel slag aggregate is 0.075mm-2.36mm. The base asphalt is SBS-modified asphalt. The microwave-absorbing modifier is prepared by surface modification of ferromagnetic powder with a silane coupling agent, and the particle size range of the microwave-absorbing modifier is 1-50μm. In practical applications, missing values ​​are filled using common basalt or limestone aggregates.

[0014] A method for preparing microwave-sensitive nickel slag composite asphalt pavement material includes: S1, preparing raw materials of each component according to a preset ratio; S2, pretreating nickel slag to obtain nickel slag coarse aggregate and nickel slag fine aggregate; S3, modifying the microwave absorber by ultrasonically dispersing ferromagnetic powder and silane coupling agent in trichloroethylene, removing the solvent to obtain a surface-functionalized microwave absorber modifier; S4, heating the base asphalt and sequentially adding the nickel slag aggregate obtained in S2, the microwave absorber obtained in S3, and mineral powder, then high-speed shearing and stirring to obtain a mixture; S5, pressing the mixture obtained in S4 into shape, controlling the porosity to 3%-6%.

[0015] The pretreatment of nickel slag in S2 includes: S2.1, mixing nickel slag and calcium oxide in a preset ratio and then carrying out a high-temperature melting oxidation reaction; S2.2, cooling the nickel slag after the reaction in S2.1 and then crushing it to collect nickel slag particles of different particle sizes; S2.3, removing impurities from the nickel slag particles collected in S2.2; S2.4, microwaving the nickel slag particles after removing impurities in S2.3, and then cooling them to obtain coarse nickel slag aggregate and fine nickel slag aggregate according to different particle size ranges.

[0016] The modification of the microwave absorbing agent in step S3 includes: S3.1, mixing Fe3O4 powder and KH550 silane coupling agent according to a preset ratio; S3.2, adding the Fe3O4 powder and KH550 silane coupling agent mixed in S3.1 to a trichloroethylene solution to obtain a mixed solution in which the trichloroethylene solution completely submerges the solid particles; S3.3, ultrasonically dispersing the mixed solution obtained in S3.2 to make the Fe3O4 powder more uniformly dispersed in the solution, thereby increasing the contact area between the Fe3O4 powder and the KH550 silane coupling agent; S3.4, drying the dispersed mixed solution in S3.3 and removing the trichloroethylene solution to finally obtain the microwave absorbing modifier.

[0017] To make this application easier to understand, specific embodiments are described below.

[0018] Example 1

[0019] The raw material ratio is as follows: base bitumen (SBS modified): 6%; nickel slag coarse aggregate (2.36–13.2 mm): 45%; nickel slag fine aggregate (0.075–2.36 mm): 35%; microwave-absorbing modified Fe3O4 powder: 7%; mineral powder: 7%. Preparation steps:

[0020] I. Melting and Oxidation Treatment of Nickel Slag

[0021] 1. Raw material preparation: Mix the nickel slag with an appropriate amount of calcium oxide. The amount of calcium oxide added should be precisely calculated based on the composition of the nickel slag and the reaction requirements. Usually, calcium oxide is added to adjust the basicity of the nickel slag to 0.6.

[0022] 2. Melt oxidation reaction: The mixed nickel slag and calcium oxide are placed in a high-temperature furnace and heated to 1400℃-1500℃. The temperature is maintained at this temperature for a melt oxidation reaction, and the reaction time is 12h.

[0023] II. Pretreatment of Nickel Slag

[0024] 1. Crushing and Screening: The cooled nickel slag is crushed to further reduce its particle size, thereby improving the efficiency of subsequent processing. The crushed nickel slag is then graded using a vibrating screen to collect nickel slag particles of different size ranges.

[0025] 2. Impurity Removal: Impurities such as iron filings, plastic fragments, and wood chips are removed from the nickel slag using physical methods such as magnetic separation and air separation. Magnetic separation effectively removes ferrous impurities, while air separation removes lighter impurities, ensuring the purity of the nickel slag.

[0026] III. Microwave treatment to activate the surface activity of nickel slag

[0027] 1. Microwave treatment: The power was set to 1.5KW, the frequency to 1GHz, and the treatment time to 60s. Microwave treatment can rapidly raise the temperature, activate the active sites on the surface of the nickel slag, and improve its bonding ability with subsequent additives.

[0028] 2. Cooling and Collection: After processing, the nickel slag is removed from the microwave reactor and allowed to cool naturally to room temperature for later use.

[0029] IV. Preparation of microwave absorbing agents

[0030] 1. Raw material preparation: Weigh an appropriate amount of Fe3O4 powder and KH550 silane coupling agent, and mix them in a mass ratio of 1:0.2.

[0031] 2. Ultrasonic dispersion: Add the mixed Fe3O4 powder and KH550 silane coupling agent to a trichloroethylene solution, ensuring the trichloroethylene completely submerges the solid particles. Place the mixed solution in an ultrasonic disperser. Ultrasonic dispersion ensures that the Fe3O4 powder is uniformly dispersed in the solution, increasing its contact area with the silane coupling agent.

[0032] 3. Drying treatment: Place the ultrasonically dispersed solution in a drying oven, set the temperature to 80℃, and dry for 2 hours to remove the trichloroethylene solvent, thus obtaining the modified microwave absorber.

[0033] V. Preparation of Composite Materials

[0034] 1. Heating of base asphalt: Place the base asphalt in a heating container, heat it to 180°C, and maintain this temperature to allow the asphalt to fully melt and remain fluid.

[0035] 2. Material mixing: Microwave-treated nickel slag, modified microwave absorber and mineral powder are added to the molten asphalt in sequence.

[0036] 3. Mixing Treatment: Use a high-speed shear mixer at a speed of 4500 rpm for 30 minutes to mix the mixture. During the mixing process, ensure that the mixture is uniformly mixed so that each component is fully dispersed in the asphalt matrix.

[0037] 4. Molding Process: After mixing, pour the mixture into a mold for molding. The molded composite material is then cooled and cured at room temperature for 24 hours.

[0038] Performance testing: Microwave heating: Under 2.45GHz microwaves, the surface temperature rise rate of the material reaches 1.0℃ / s (0.3℃ / s for ordinary asphalt); Road performance indicators: Dynamic stability 6400 times / mm (the specification requires ≥3000 times / mm), meeting the needs of heavy-duty traffic.

[0039] Example 2

[0040] Raw material ratio: Base bitumen (SBS modified): 6%; coarse nickel slag aggregate (2.36–13.2 mm): 42.5%; fine nickel slag aggregate (0.075–2.36 mm): 32.5%; microwave-absorbing modified Fe3O4 powder: 6%; mineral powder: 7%. Preparation steps:

[0041] I. Melting and Oxidation Treatment of Nickel Slag

[0042] 1. Raw material preparation: Mix the nickel slag with an appropriate amount of calcium oxide. The amount of calcium oxide added should be precisely calculated based on the composition of the nickel slag and the reaction requirements. Usually, calcium oxide is added to adjust the basicity of the nickel slag to 0.6.

[0043] 2. Melt oxidation reaction: The mixed nickel slag and calcium oxide are placed in a high-temperature furnace and heated to 1400℃-1500℃. The temperature is maintained at this temperature for a melt oxidation reaction, and the reaction time is 12h.

[0044] II. Pretreatment of Nickel Slag

[0045] 1. Crushing and Screening: The cooled nickel slag is crushed to further reduce its particle size, thereby improving the efficiency of subsequent processing. The crushed nickel slag is then graded using a vibrating screen to collect nickel slag particles of different size ranges.

[0046] 2. Impurity Removal: Impurities such as iron filings, plastic fragments, and wood chips are removed from the nickel slag using physical methods such as magnetic separation and air separation. Magnetic separation effectively removes ferrous impurities, while air separation removes lighter impurities, ensuring the purity of the nickel slag.

[0047] III. Microwave treatment to activate the surface activity of nickel slag

[0048] 1. Microwave treatment: The power was set to 1.5KW, the frequency to 1GHz, and the treatment time to 60s. Microwave treatment can rapidly raise the temperature, activate the active sites on the surface of the nickel slag, and improve its bonding ability with subsequent additives.

[0049] 2. Cooling and Collection: After processing, the nickel slag is removed from the microwave reactor and allowed to cool naturally to room temperature for later use.

[0050] IV. Preparation of microwave absorbing agents

[0051] 1. Raw material preparation: Weigh an appropriate amount of Fe3O4 powder and KH550 silane coupling agent, and mix them in a mass ratio of 1:0.2.

[0052] 2. Ultrasonic dispersion: Add the mixed Fe3O4 powder and KH550 silane coupling agent to a trichloroethylene solution, ensuring the trichloroethylene completely submerges the solid particles. Place the mixed solution in an ultrasonic disperser. Ultrasonic dispersion ensures that the Fe3O4 powder is uniformly dispersed in the solution, increasing its contact area with the silane coupling agent.

[0053] 3. Drying treatment: Place the ultrasonically dispersed solution in a drying oven, set the temperature to 80℃, and dry for 2 hours to remove the trichloroethylene solvent, thus obtaining the modified microwave absorber.

[0054] V. Preparation of Composite Materials

[0055] 1. Heating of base asphalt: Place the base asphalt in a heating container, heat it to 180°C, and maintain this temperature to allow the asphalt to fully melt and remain fluid.

[0056] 2. Material mixing: Microwave-treated nickel slag, modified microwave absorber and mineral powder are added to the molten asphalt in sequence.

[0057] 3. Mixing Treatment: Use a high-speed shear mixer at a speed of 4500 rpm for 30 minutes to mix the mixture. During the mixing process, ensure that the mixture is uniformly mixed so that each component is fully dispersed in the asphalt matrix.

[0058] 4. Molding Process: After mixing, pour the mixture into a mold for molding. The molded composite material is then cooled and cured at room temperature for 24 hours.

[0059] Performance testing:

[0060] Microwave heating: Under 2.45GHz microwaves, the surface temperature rise rate of the material reaches 0.8℃ / s (compared to 0.3℃ / s for ordinary asphalt).

[0061] Road performance indicators: Dynamic stability 5900 cycles / mm (standard requirement ≥3000 cycles / mm), meeting the needs of heavy-duty traffic.

[0062] Example 3

[0063] Raw material ratio: Base bitumen (SBS modified): 6%; Nickel slag coarse aggregate (2.36–13.2 mm): 40%; Nickel slag fine aggregate (0.075–2.36 mm): 30%; Microwave-absorbing modified Fe3O4 powder: 5%; Mineral powder: 7%. Preparation steps:

[0064] I. Melting and Oxidation Treatment of Nickel Slag

[0065] 1. Raw material preparation: Mix the nickel slag with an appropriate amount of calcium oxide. The amount of calcium oxide added should be precisely calculated based on the composition of the nickel slag and the reaction requirements. Usually, calcium oxide is added to adjust the basicity of the nickel slag to 0.6.

[0066] 2. Melt oxidation reaction: The mixed nickel slag and calcium oxide are placed in a high-temperature furnace and heated to 1400℃-1500℃. The temperature is maintained at this temperature for a melt oxidation reaction, and the reaction time is 12h.

[0067] II. Pretreatment of Nickel Slag

[0068] 1. Crushing and Screening: The cooled nickel slag is crushed to further reduce its particle size, thereby improving the efficiency of subsequent processing. The crushed nickel slag is then graded using a vibrating screen to collect nickel slag particles of different size ranges.

[0069] 2. Impurity Removal: Impurities such as iron filings, plastic fragments, and wood chips are removed from the nickel slag using physical methods such as magnetic separation and air separation. Magnetic separation effectively removes ferrous impurities, while air separation removes lighter impurities, ensuring the purity of the nickel slag.

[0070] III. Microwave treatment to activate the surface activity of nickel slag

[0071] 1. Microwave treatment: The power was set to 1.5KW, the frequency to 1GHz, and the treatment time to 60s. Microwave treatment can rapidly raise the temperature, activate the active sites on the surface of the nickel slag, and improve its bonding ability with subsequent additives.

[0072] 2. Cooling and Collection: After processing, the nickel slag is removed from the microwave reactor and allowed to cool naturally to room temperature for later use.

[0073] IV. Preparation of microwave absorbing agents

[0074] 1. Raw material preparation: Weigh an appropriate amount of Fe3O4 powder and KH550 silane coupling agent, and mix them in a mass ratio of 1:0.2.

[0075] 2. Ultrasonic dispersion: Add the mixed Fe3O4 powder and KH550 silane coupling agent to a trichloroethylene solution, ensuring the trichloroethylene completely submerges the solid particles. Place the mixed solution in an ultrasonic disperser. Ultrasonic dispersion ensures that the Fe3O4 powder is uniformly dispersed in the solution, increasing its contact area with the silane coupling agent.

[0076] 3. Drying treatment: Place the ultrasonically dispersed solution in a drying oven, set the temperature to 80℃, and dry for 2 hours to remove the trichloroethylene solvent, thus obtaining the modified microwave absorber.

[0077] V. Preparation of Composite Materials

[0078] 1. Heating of base asphalt: Place the base asphalt in a heating container, heat it to 180°C, and maintain this temperature to allow the asphalt to fully melt and remain fluid.

[0079] 2. Material mixing: Microwave-treated nickel slag, modified microwave absorber and mineral powder are added to the molten asphalt in sequence.

[0080] 3. Mixing Treatment: Use a high-speed shear mixer at a speed of 4500 rpm for 30 minutes to mix the mixture. During the mixing process, ensure that the mixture is uniformly mixed so that each component is fully dispersed in the asphalt matrix.

[0081] 4. Molding Process: After mixing, pour the mixture into a mold for molding. The molded composite material is then cooled and cured at room temperature for 24 hours.

[0082] Performance testing:

[0083] Microwave heating: Under 2.45GHz microwaves, the surface temperature rise rate of the material reaches 0.7℃ / s (compared to 0.3℃ / s for ordinary asphalt).

[0084] Road performance indicators: Dynamic stability 5800 cycles / mm (standard requirement ≥3000 cycles / mm), meeting the needs of heavy-duty traffic.

Claims

1. A microwave-sensitive nickel slag composite asphalt pavement material, characterized in that, Includes the following components in percentage terms: Nickel slag aggregate accounts for 70%-80%, specifically including 40%-45% coarse nickel slag aggregate and 30%-35% fine nickel slag aggregate; Base asphalt 5%-6%; 5%-7% microwave absorbing modifier; Mineral powder 6%-7%.

2. The microwave-sensitive nickel slag composite asphalt pavement material as described in claim 1, characterized in that, The coarse nickel slag aggregate has a particle size of 2.36 mm–13.2 mm, and the fine nickel slag aggregate has a particle size of 0.075 mm–2.36 mm.

3. The microwave-sensitive nickel slag composite asphalt pavement material as described in claim 1, characterized in that, The base asphalt was set as SBS modified asphalt.

4. The microwave-sensitive nickel slag composite asphalt pavement material as described in claim 1, characterized in that, The microwave absorbing modifier is prepared by surface modification of ferromagnetic powder with a silane coupling agent, and the particle size range of the microwave absorbing modifier is 1–50 μm.

5. A method for preparing microwave-sensitive nickel slag composite asphalt pavement material, used to prepare the microwave-sensitive nickel slag composite asphalt pavement material as described in claims 1-4, characterized in that, include: S1. Prepare the raw materials of each component according to the preset ratio; S2. Pre-treat the nickel slag to obtain coarse nickel slag aggregate and fine nickel slag aggregate; S3. Modification of microwave absorbing agent: Ferromagnetic powder and silane coupling agent are ultrasonically dispersed in trichloroethylene, and the surface functionalized microwave absorbing modifier is obtained after removing the solvent. S4. After heating the base asphalt, add the nickel slag aggregate obtained in S2, the microwave absorber obtained in S3, and the mineral powder in sequence, and then shear and stir at high speed to obtain a mixture; S5. The mixture obtained in S4 is pressed and molded, and the porosity is controlled to be 3%-6%.

6. The method for preparing microwave-sensitive nickel slag composite asphalt pavement material as described in claim 5, characterized in that, The pretreatment of nickel slag in S2 includes: S2.

1. Nickel slag and calcium oxide are mixed in a preset ratio and then subjected to a high-temperature melting oxidation reaction. S2.2 After cooling the nickel slag reacted in S2.1, crush it and collect nickel slag particles of different particle sizes. S2.3, The nickel slag particles collected in S2.2 are subjected to slag removal treatment; S2.

4. Microwave treatment is performed on the nickel slag particles after slag removal in S2.

3. After cooling, nickel slag coarse aggregate and nickel slag fine aggregate are obtained according to different particle size ranges.

7. The method for preparing microwave-sensitive nickel slag composite asphalt pavement material as described in claim 5, characterized in that, The modification of the microwave absorber in S3 includes: S3.1 Mix Fe3O4 powder and KH550 silane coupling agent according to a preset ratio; S3.2 Add the Fe3O4 powder and KH550 silane coupling agent mixed in S3.1 to the trichloroethylene solution to obtain a mixed solution, wherein the trichloroethylene solution completely submerges the solid particles; S3.

3. The mixed solution obtained in S3.2 is ultrasonically dispersed to make the Fe3O4 powder more uniformly dispersed in the solution, thereby increasing the contact area between the Fe3O4 powder and the KH550 silane coupling agent. S3.

4. The mixed solution dispersed in S3.3 is dried and the trichloroethylene solution is removed to finally obtain the microwave absorbing modifier.

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