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

Abstract

The invention discloses a microwave-sensitive nickel slag composite asphalt pavement material. The microwave-sensitive nickel slag composite asphalt pavement material comprises the following components in percentage: 60-70% of nickel slag aggregate, 5-6% of matrix asphalt, 3-5% of a wave-absorbing modifier and 2-6% of mineral powder. A preparation method of the microwave-sensitive nickel slag composite asphalt pavement material is used for preparing the microwave-sensitive nickel slag composite asphalt pavement material and comprises the following steps: S1, preparing the raw materials according to the preset proportion; s2, nickel slag is pretreated, and nickel slag coarse aggregate and nickel slag fine aggregate are obtained; s3, modifying a wave-absorbing agent, ultrasonically dispersing the ferromagnetic powder and a silane coupling agent in trichloroethylene, and removing a solvent to obtain a surface functionalized wave-absorbing modifier; s4, heating matrix asphalt, sequentially adding the nickel slag aggregate obtained in the step S2, the wave absorbing agent obtained in the step S3 and mineral powder, and then performing high-speed shearing and stirring to obtain a mixture; and S5, carrying out compression molding on the mixture obtained in the step S4, and controlling the void ratio to be 3-6%.

Description

Technical Field

[0001] The invention belongs to the technical field of comprehensive utilization of metallurgical solid waste and road engineering materials, and particularly relates to a microwave-sensitive nickel slag composite asphalt pavement material and a preparation method thereof. Background Art

[0002] Traditional road snow and ice removal methods have problems such as low efficiency, environmental pollution and high cost: Mechanical / artificial snow removal: As a traditional snow removal method, artificial snow removal is highly flexible and does not require complex equipment, but it has significant drawbacks, including low efficiency, high cost, and prominent safety hazards during operation. Snow melting agents: Currently commonly used chloride-based snow melting agents can easily cause soil salinization and vegetation damage, and can also cause groundwater pollution. Microwave heating technology: Existing microwave snow removal devices have problems such as insufficient penetration depth and low microwave absorption efficiency. The pavement material itself has a weak response to microwaves, 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 material in the oxidized nickel slag can be used to enhance the microwave absorption capacity of asphalt pavement. However, the nickel slag in the existing technology contains heavy metal elements. When preparing road materials, the leaching rate of heavy metal elements must be considered to ensure that no environmental pollution will occur. Therefore, there is an urgent need to develop an asphalt pavement material that combines microwave sensitivity and road performance. Application Contents

[0003] The purpose of this application is to provide a microwave-sensitive nickel slag composite asphalt pavement material and a preparation method thereof. The specific technical solution is as follows: A microwave-sensitive nickel slag composite asphalt pavement material comprises the following components in percentage: 60%-70% nickel slag aggregate, 5%-6% base asphalt, 3%-5% microwave absorbing modifier, and 2%-6% mineral powder.

[0004] The 60%-70% nickel slag aggregate consists of 30%-45% coarse aggregate and 20%-50% fine aggregate. The coarse aggregate particle size ranges from 2.36mm to 13.2mm, and the fine aggregate particle size ranges from 0.075mm to 2.36mm. The base asphalt is SBS-modified asphalt. The microwave-absorbing modifier is prepared by surface-modifying ferromagnetic powder with a silane coupling agent. The particle size of the microwave-absorbing modifier ranges from 1 to 50μm.

[0005] A method for preparing a microwave-sensitive nickel slag composite asphalt pavement material is used to prepare the microwave-sensitive nickel slag composite asphalt pavement material, comprising: S1, preparing raw materials of various components according to a preset ratio; S2, pretreating the nickel slag to obtain nickel slag coarse aggregate and nickel slag fine aggregate; S3, modifying the absorber by ultrasonically dispersing ferromagnetic powder and a silane coupling agent in trichloroethylene, and removing the solvent to obtain a surface functionalized absorber modifier; S4, heating the matrix asphalt and sequentially adding the nickel slag aggregate obtained in S2, the absorber obtained in S3, and mineral powder, followed by high-speed shear stirring to obtain a mixture; and S5, pressing and molding the mixture obtained in S4, controlling the porosity to be 3%-6%.

[0006] The pretreatment of nickel slag in S2 includes: S2.1, mixing nickel slag and calcium oxide in a preset proportion and then performing a high-temperature melting oxidation reaction; S2.2, cooling the nickel slag after the reaction in S2.1 and then breaking it, and collecting nickel slag particles in different particle size ranges; S2.3, deslagging the nickel slag particles collected in S2.2; S2.4, microwave-treating the nickel slag particles after deslagging in S2.3, and obtaining nickel slag coarse aggregate and nickel slag fine aggregate according to different particle size ranges after cooling.

[0007] The modification of the absorber in 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, wherein the trichloroethylene solution completely immerses 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 mixed solution dispersed in S3.3 and removing the trichloroethylene solution, thereby finally obtaining the absorber modifier.

[0008] The beneficial effects of the present application are that, through the design of the present application, the microwave heating rate is increased by more than 60% (compared with ordinary asphalt), and a 2 cm thick ice layer can be melted within 10-15 minutes, which can save 30%-40% energy compared with traditional heating methods; nickel slag is recycled from industrial waste, which can achieve effective recycling and reuse of resources, reduce negative impacts on the environment, and at the same time reduce road infrastructure costs by 30%-40%; microwave treatment reduces high-temperature oxidation of asphalt, delays material aging, and meets the rutting resistance and durability requirements of high-altitude cold areas; it is compatible with existing asphalt paving equipment and does not require additional equipment replacement; the microwave power is adjustable in real time, facilitating automated construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1This is a schematic flow chart of the method for preparing microwave-sensitive nickel slag composite asphalt pavement material in this application. Specific embodiments

[0010] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0011] A microwave-sensitive nickel slag composite asphalt pavement material comprises the following components in percentage: 60%-70% nickel slag aggregate, 5%-6% base asphalt, 3%-5% microwave absorbing modifier, and 2%-6% mineral powder.

[0012] The 60%-70% nickel slag aggregate consists of 30%-45% coarse aggregate and 20%-50% fine aggregate. The coarse aggregate particle size ranges from 2.36mm to 13.2mm, and the fine aggregate particle size ranges from 0.075mm to 2.36mm. The base asphalt is SBS-modified asphalt. The microwave-absorbing modifier is prepared by surface-modifying ferromagnetic powder with a silane coupling agent. The particle size of the microwave-absorbing modifier ranges from 1 to 50μm.

[0013] A method for preparing a microwave-sensitive nickel slag composite asphalt pavement material is used to prepare the microwave-sensitive nickel slag composite asphalt pavement material, comprising: S1, preparing raw materials of various components according to a preset ratio; S2, pretreating the nickel slag to obtain nickel slag coarse aggregate and nickel slag fine aggregate; S3, modifying the absorber by ultrasonically dispersing ferromagnetic powder and a silane coupling agent in trichloroethylene, and removing the solvent to obtain a surface functionalized absorber modifier; S4, heating the matrix asphalt and sequentially adding the nickel slag aggregate obtained in S2, the absorber obtained in S3, and mineral powder, followed by high-speed shear stirring to obtain a mixture; and S5, pressing and molding the mixture obtained in S4, controlling the porosity to be 3%-6%.

[0014] The pretreatment of nickel slag in S2 includes: S2.1, mixing nickel slag and calcium oxide in a preset proportion and then performing a high-temperature melting oxidation reaction; S2.2, cooling the nickel slag after the reaction in S2.1 and then breaking it, and collecting nickel slag particles in different particle size ranges; S2.3, deslagging the nickel slag particles collected in S2.2; S2.4, microwave-treating the nickel slag particles after deslagging in S2.3, and obtaining nickel slag coarse aggregate and nickel slag fine aggregate according to different particle size ranges after cooling.

[0015] The modification of the absorber in 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, wherein the trichloroethylene solution completely immerses 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 mixed solution dispersed in S3.3 and removing the trichloroethylene solution, thereby finally obtaining the absorber modifier.

[0016] In order to make this application easier to understand, it is described below in conjunction with specific implementation methods.

[0017] Example 1 The raw material ratio is: matrix asphalt (SBS modified): 6%; nickel slag coarse aggregate (2.36–13.2 mm): 30%; nickel slag fine aggregate (0.075–2.36 mm): 54%; wave-absorbing modified Fe3O4 powder: 5%; mineral powder: 5%.

[0018] Preparation steps: 1. Melting oxidation treatment of nickel slag 1. Raw material preparation: Mix nickel slag with an appropriate amount of calcium oxide. The amount of calcium oxide added is accurately calculated based on the composition of the nickel slag and the reaction requirements. Generally, the mass ratio of calcium oxide to nickel slag is 1:5 to 1:10.

[0019] 2. Melt oxidation reaction: Place the mixed nickel slag and calcium oxide in a high-temperature furnace, heat it to 1200°C-1400°C, and maintain this temperature for melt oxidation reaction for 24 hours.

[0020] 2. Pretreatment of nickel slag 1. Crushing and screening: The cooled nickel slag is crushed to further reduce its particle size to improve the effect of subsequent processing. The crushed nickel slag is graded by a vibrating screen to collect nickel slag particles of different particle size ranges.

[0021] 2. Impurity Removal: Impurities such as iron filings, plastic fragments, and wood chips are removed from the nickel slag through physical methods such as magnetic separation and air separation. Magnetic separation effectively removes iron impurities, while air separation removes light impurities, ensuring the purity of the nickel slag.

[0022] 3. Microwave treatment stimulates the surface activity of nickel slag 1. Microwave treatment: Set the power to 1.5 kW, the frequency to 1 GHz, and the treatment time to 60 seconds. Microwave treatment can quickly heat up, stimulating the active sites on the surface of the nickel slag and improving its ability to bond with subsequent additives.

[0023] 2. Cooling and collection: After the treatment is completed, the nickel slag is taken out from the microwave reactor, cooled naturally to room temperature, and set aside.

[0024] 4. Preparation of absorber 1. Raw material preparation: Weigh appropriate amounts of Fe3O4 powder and KH550 silane coupling agent and mix them in a mass ratio of 1:0.2.

[0025] 2. Ultrasonic dispersion: Add the mixed Fe3O4 powder and KH550 silane coupling agent to a trichloroethylene solution. The amount of trichloroethylene used should be sufficient to completely submerge the solid particles. Place the mixed solution in an ultrasonic disperser. Ultrasonic dispersion can evenly disperse the Fe3O4 powder in the solution, increasing its contact area with the silane coupling agent.

[0026] 3. Drying treatment: Place the ultrasonically dispersed solution in a drying oven, set the temperature to 80°C, and dry it for 2 hours to remove the trichloroethylene solvent to obtain a modified absorber.

[0027] 5. Preparation of composite materials 1. Heating of base asphalt: Place the base asphalt in a heating container, raise the temperature to 180°C, and maintain this temperature to allow the asphalt to fully melt and maintain fluidity.

[0028] 2. Material mixing: Add microwave-treated nickel slag, modified absorber and mineral powder to the melted asphalt in sequence.

[0029] 3. Mixing: Use a high-speed shear mixer to stir the mixture at a speed of 4500r / min for 30 minutes. During the stirring process, ensure that the mixture is evenly mixed and all components are fully dispersed in the asphalt matrix.

[0030] 4. Molding: After stirring, pour the mixture into a mold for molding. The molded composite material is cooled and solidified at room temperature for 24 hours.

[0031] Performance test: Microwave heating: Under 2.45GHz microwave, the material surface heating rate reaches 0.8℃ / s (compared to 0.3℃ / s for ordinary asphalt); road use indicators: dynamic stability 6200 times / mm (standard requirement ≥3000 times / mm), meeting the needs of heavy-load traffic.

[0032] Example 2 Raw material ratio: matrix asphalt (SBS modified): 6%; nickel slag coarse aggregate (2.36–13.2 mm): 35%; nickel slag fine aggregate (0.075–2.36 mm): 49%; wave-absorbing modified Fe3O4 powder: 5%; mineral powder: 5%.

[0033] Preparation steps: 1. Melt oxidation treatment of nickel slag 1. Raw material preparation: Mix nickel slag with an appropriate amount of calcium oxide. The amount of calcium oxide added is accurately calculated based on the composition of the nickel slag and the reaction requirements. Generally, the mass ratio of calcium oxide to nickel slag is 1:5 to 1:10.

[0034] 2. Melt oxidation reaction: Place the mixed nickel slag and calcium oxide in a high-temperature furnace, heat it to 1200°C-1400°C, and maintain this temperature for melt oxidation reaction for 24 hours.

[0035] 2. Pretreatment of nickel slag 1. Crushing and screening: The cooled nickel slag is crushed to further reduce its particle size to improve the effect of subsequent processing. The crushed nickel slag is graded by a vibrating screen to collect nickel slag particles of different particle size ranges.

[0036] 2. Impurity Removal: Impurities such as iron filings, plastic fragments, and wood chips are removed from the nickel slag through physical methods such as magnetic separation and air separation. Magnetic separation effectively removes iron impurities, while air separation removes light impurities, ensuring the purity of the nickel slag.

[0037] 3. Microwave treatment stimulates the surface activity of nickel slag 1. Microwave treatment: Set the power to 1.5 kW, the frequency to 1 GHz, and the treatment time to 60 seconds. Microwave treatment can quickly heat up, stimulating the active sites on the surface of the nickel slag and improving its ability to bond with subsequent additives.

[0038] 2. Cooling and collection: After the treatment is completed, the nickel slag is taken out from the microwave reactor, cooled naturally to room temperature, and set aside.

[0039] 4. Preparation of absorber 1. Raw material preparation: Weigh appropriate amounts of Fe3O4 powder and KH550 silane coupling agent and mix them in a mass ratio of 1:0.2.

[0040] 2. Ultrasonic dispersion: Add the mixed Fe3O4 powder and KH550 silane coupling agent to a trichloroethylene solution. The amount of trichloroethylene used should be sufficient to completely submerge the solid particles. Place the mixed solution in an ultrasonic disperser. Ultrasonic dispersion can evenly disperse the Fe3O4 powder in the solution, increasing its contact area with the silane coupling agent.

[0041] 3. Drying treatment: Place the ultrasonically dispersed solution in a drying oven, set the temperature to 80°C, and dry it for 2 hours to remove the trichloroethylene solvent to obtain a modified absorber.

[0042] 5. Preparation of composite materials 1. Heating of base asphalt: Place the base asphalt in a heating container, raise the temperature to 180°C, and maintain this temperature to allow the asphalt to fully melt and maintain fluidity.

[0043] 2. Material mixing: Add microwave-treated nickel slag, modified absorber and mineral powder to the melted asphalt in sequence.

[0044] 3. Mixing: Use a high-speed shear mixer to stir the mixture at a speed of 4500r / min for 30 minutes. During the stirring process, ensure that the mixture is evenly mixed and all components are fully dispersed in the asphalt matrix.

[0045] 4. Molding: After stirring, pour the mixture into a mold for molding. The molded composite material is cooled and solidified at room temperature for 24 hours.

[0046] Performance testing: Microwave heating: Under 2.45GHz microwave, the material surface heating rate reaches 0.7℃ / s (common asphalt is 0.3℃ / s); Road use indicators: dynamic stability 6000 times / mm (standard requirement ≥3000 times / mm), meeting heavy-load traffic needs.

[0047] Example 3 Raw material ratio: matrix asphalt (SBS modified): 6%; nickel slag coarse aggregate (2.36–13.2 mm): 32%; nickel slag fine aggregate (0.075–2.36 mm): 52%; absorbing modified Fe3O4 powder: 5%; mineral powder: 5%.

[0048] Preparation steps: 1. Melt oxidation treatment of nickel slag 1. Raw material preparation: Mix nickel slag with an appropriate amount of calcium oxide. The amount of calcium oxide added is accurately calculated based on the composition of the nickel slag and the reaction requirements. Generally, the mass ratio of calcium oxide to nickel slag is 1:5 to 1:10.

[0049] 2. Melt oxidation reaction: Place the mixed nickel slag and calcium oxide in a high-temperature furnace, heat it to 1200°C-1400°C, and maintain this temperature for melt oxidation reaction for 24 hours.

[0050] 2. Pretreatment of nickel slag 1. Crushing and screening: The cooled nickel slag is crushed to further reduce its particle size to improve the effect of subsequent processing. The crushed nickel slag is graded by a vibrating screen to collect nickel slag particles of different particle size ranges.

[0051] 2. Impurity Removal: Impurities such as iron filings, plastic fragments, and wood chips are removed from the nickel slag through physical methods such as magnetic separation and air separation. Magnetic separation effectively removes iron impurities, while air separation removes light impurities, ensuring the purity of the nickel slag.

[0052] 3. Microwave treatment stimulates the surface activity of nickel slag 1. Microwave treatment: Set the power to 1.5 kW, the frequency to 1 GHz, and the treatment time to 60 seconds. Microwave treatment can quickly heat up, stimulating the active sites on the surface of the nickel slag and improving its ability to bond with subsequent additives.

[0053] 2. Cooling and collection: After the treatment is completed, the nickel slag is taken out from the microwave reactor, cooled naturally to room temperature, and set aside.

[0054] 4. Preparation of absorber 1. Raw material preparation: Weigh appropriate amounts of Fe3O4 powder and KH550 silane coupling agent and mix them in a mass ratio of 1:0.2.

[0055] 2. Ultrasonic dispersion: Add the mixed Fe3O4 powder and KH550 silane coupling agent to a trichloroethylene solution. The amount of trichloroethylene used should be sufficient to completely submerge the solid particles. Place the mixed solution in an ultrasonic disperser. Ultrasonic dispersion can evenly disperse the Fe3O4 powder in the solution, increasing its contact area with the silane coupling agent.

[0056] 3. Drying treatment: Place the ultrasonically dispersed solution in a drying oven, set the temperature to 80°C, and dry it for 2 hours to remove the trichloroethylene solvent to obtain a modified absorber.

[0057] 5. Preparation of composite materials 1. Heating of base asphalt: Place the base asphalt in a heating container, raise the temperature to 180°C, and maintain this temperature to allow the asphalt to fully melt and maintain fluidity.

[0058] 2. Material mixing: Add microwave-treated nickel slag, modified absorber and mineral powder to the melted asphalt in sequence.

[0059] 3. Mixing: Use a high-speed shear mixer to stir the mixture at a speed of 4500r / min for 30 minutes. During the stirring process, ensure that the mixture is evenly mixed and all components are fully dispersed in the asphalt matrix.

[0060] 4. Molding: After stirring, pour the mixture into a mold for molding. The molded composite material is cooled and solidified at room temperature for 24 hours.

[0061] Performance testing: Microwave heating: Under 2.45GHz microwave, the material surface heating rate reaches 0.7℃ / s (common asphalt is 0.3℃ / s); Road use indicators: dynamic stability 5900 times / mm (standard requirement ≥3000 times / mm), meeting heavy-load traffic needs.

Claims

1. A microwave-sensitive nickel slag composite asphalt pavement material, characterized in that: Contains the following components in percentage: Nickel slag aggregate 60%-70%, including nickel slag coarse aggregate 30%-45% and nickel slag fine aggregate 20%-50%; Matrix asphalt 5%-6%, Absorbing modifier 3%-5%, Mineral powder 2%-6%.

2. The microwave-sensitive nickel slag composite asphalt pavement material according to claim 1, characterized in that: The particle size of the nickel slag coarse aggregate is 2.36 mm-13.2 mm, and the particle size of the nickel slag fine aggregate is 0.075 mm-2.36 mm.

3. The microwave-sensitive nickel slag composite asphalt pavement material according to claim 1, characterized in that: The matrix asphalt is set to SBS modified asphalt.

4. The microwave-sensitive nickel slag composite asphalt pavement material according to claim 1, characterized in that: The wave-absorbing modifier is prepared by surface-modifying ferromagnetic powder with a silane coupling agent, and the particle size of the wave-absorbing modifier ranges from 1 to 50 μm.

5. A method for preparing a microwave-sensitive nickel slag composite asphalt pavement material, for preparing the microwave-sensitive nickel slag composite asphalt pavement material according to claims 1-4, characterized in that: include: S1. Prepare the raw materials of each component according to the preset ratio; S2. pretreating the nickel slag to obtain nickel slag coarse aggregate and nickel slag fine aggregate; S3, modifying the absorber by ultrasonically dispersing the ferromagnetic powder and the silane coupling agent in trichloroethylene, and removing the solvent to obtain a surface functionalized absorber modifier; S4, heating the matrix asphalt and sequentially adding the nickel slag aggregate obtained in S2, the absorber obtained in S3, and the mineral powder, followed by high-speed shear stirring to obtain a mixture; S5. Pressing and molding the mixture obtained in S4 to control the void ratio to be 3%-6%.

6. The method for preparing a microwave-sensitive nickel slag composite asphalt pavement material according to claim 5, characterized in that: The pretreatment of nickel slag in S2 includes: S2.1, mixing nickel slag and calcium oxide in a predetermined ratio and performing a high-temperature melt oxidation reaction; S2.2, cooling the nickel slag after the reaction in S2.1 and performing a crushing treatment, and collecting nickel slag particles of different particle size ranges; S2.3, removing the nickel slag particles collected in S2.2; S2.

4. The nickel slag particles after slag removal in S2.3 are subjected to microwave treatment, and after cooling, nickel slag coarse aggregate and nickel slag fine aggregate are obtained according to different particle size ranges.

7. The method for preparing a microwave-sensitive nickel slag composite asphalt pavement material according to claim 5, characterized in that: The modification of the absorber in S3 includes: S3.1, Fe3O4 powder and KH550 silane coupling agent are mixed according to a preset ratio; S3.2, adding 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 immerses 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. Dry the mixed solution dispersed in S3.3 and remove the trichloroethylene solution to finally obtain a microwave absorbing modifier.

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