Wave-absorbing tailing coating for road, wave-absorbing tailing for road and wave-absorbing material for road

Abstract

The invention discloses a road wave-absorbing tailing coating, road wave-absorbing tailings and a road wave-absorbing material. The coating is prepared from the following raw materials: silica sol, organic silicon resin, core-shell phase change microspheres, nano-zinc oxide whiskers and hydrophobic associated sodium polyacrylate. The preparation method of the core-shell phase change microspheres comprises the following steps: dispersing quartz sand loaded with a core material in an organic solvent, uniformly mixing, adding silane coupling agent modified VO2 powder, uniformly mixing, standing, aging, filtering and drying to obtain the core-shell phase change microspheres. The coating dipping and drying curing process is applied to the surface of the tailings. After the coating is fixed on the surface of the wave-absorbing tailings, the microwave absorbing capacity of the tailings can be remarkably regulated and controlled, the upper temperature rise limit of the wave-absorbing tailings is further changed, and the purpose that asphalt is not damaged by high temperature is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering, in particular to a road wave-absorbing tailing coating, a road wave-absorbing tailing and a road wave-absorbing material. BACKGROUND

[0002] The road surface material that can be repaired by microwaves mainly is the wave-absorbing tailing produced in the process of mining, ore dressing or metallurgy, which is rich in magnetite, iron oxide and steel slag derived components. These substances can efficiently convert microwave electromagnetic energy into heat energy through the synergistic effect of dielectric loss, magnetic hysteresis loss and interface loss, and the wave-absorbing efficiency is much better than that of conventional stone aggregate such as limestone and granite.

[0003] In order to improve the microwave heating efficiency, the wave-absorbing tailing can be partially or completely replaced by conventional stone aggregate. However, the wave-absorbing tailing itself has composition inhomogeneity and has a "thermal self-enhancement effect", that is, the wave-absorbing ability continues to rise with the increase of temperature, resulting in the difference in temperature rise behavior in the microwave field. SUMMARY

[0004] In view of the defects or deficiencies of the prior art, the present application provides a road wave-absorbing tailing coating.

[0005] Therefore, the preparation raw materials of the road wave-absorbing tailing coating provided by the present application include: 45-60 parts by mass of silica sol, 20-30 parts by mass of silicone resin, 18-22 parts by mass of core-shell phase change microspheres, 1.5-2.5 parts by mass of nano zinc oxide whiskers and 0.3-0.6 parts by mass of hydrophobic association polyacrylic acid sodium. The preparation method of the core-shell phase change microspheres includes: dispersing quartz sand loaded with core material in a precursor solvent, uniformly mixing, adding VO2 powder modified by a silane coupling agent, continuing to mix, standing and aging, filtering and drying to obtain the core-shell phase change microspheres. The preparation method of the quartz sand loaded with core material includes: soaking quartz sand in molten organic phase change core material, and then collecting the solid as quartz sand loaded with core material; and the organic phase change core material is selected from paraffin or fatty acid. The precursor solvent is selected from tetraethyl orthosilicate or aluminum isopropyl alcohol; The preparation method of the VO2 powder modified by the silane coupling agent includes: dispersing VO2 powder in a silane coupling agent solution, uniformly mixing and drying to obtain the VO2 powder modified by the silane coupling agent. The mass ratio of the quartz sand to the VO2 powder is (10-20):1.

[0006] Optionally, the mass ratio of the organic phase change core material to the quartz sand is (1.5-2.5):1.

[0007] Optionally, the mass ratio of the VO2 powder to the silane coupling agent is (20-100):1.

[0008] Optionally, the preparation of the quartz sand loaded with the core material is performed at 0.1-0.3 MPa.

[0009] Optionally, the preparation method of the coating comprises the following steps: firstly, ball-milling mixing the core-shell phase change microspheres and the hydrophobic associated sodium polyacrylate; then, uniformly mixing the silica sol, the silicone resin and the nano zinc oxide whisker, and placing the mixture under vacuum condition for defoaming treatment; and finally, standing and aging to obtain the coating.

[0010] The application further provides a corresponding road wave-absorbing tailings, which comprises a basic tailings, and the basic tailings is magnetite or steel slag. The road wave-absorbing tailings is obtained by soaking the basic tailings in the coating. Optionally, the preparation method of the road wave-absorbing tailings comprises the following steps: soaking the tailings after acid washing in a silane coupling agent solution, and then standing the soaked tailings at room temperature-400 DEG C to obtain a pretreated tailings; then, soaking the pretreated tailings in the coating, and then filtering and collecting the solid material, and standing and solidifying the solid material at room temperature-200 DEG C to obtain the road wave-absorbing tailings.

[0011] Optionally, the soaked tailings are stood at room temperature-400 DEG C in an inert atmosphere to obtain the pretreated tailings; then, the pretreated tailings are soaked in the coating, and then the solid material is collected by filtration, and the solid material is stood and solidified at room temperature-200 DEG C in an inert atmosphere to obtain the road wave-absorbing tailings. Further optionally, the solidification process is performed in stages, that is, the material is first heated to a lower temperature and stood for a reasonable time, and then the temperature is continuously increased and stood, and the operation is repeated for multiple stages to complete the solidification of the material.

[0012] The application further provides a road wave-absorbing material, and the preparation raw materials of the road wave-absorbing material comprise aggregate, filler and asphalt, and the preparation raw materials of the road wave-absorbing material further comprise the road wave-absorbing tailings. The gradation of the road wave-absorbing material is determined according to the gradation of the pavement asphalt mixture, and part of the filler or aggregate of the corresponding particle size is replaced by the road wave-absorbing tailings in the process.

[0013] After the coating is fixed on the surface of the wave-absorbing tailings, the microwave absorption capacity of the tailings can be significantly regulated, and the upper limit of the temperature rise of the wave-absorbing tailings is changed, so that the asphalt is not damaged by high temperature.

[0014] The coating can ensure that the heating temperature of the asphalt pavement is controlled below 70 DEG C (as shown in FIG. 2), and the volatilization of the components of the asphalt pavement is reduced, so that the pollution of harmful substances to the environment is weakened. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a schematic diagram of the mixture gradation curve in the embodiment of the present application.

[0016] Figure 2 is a diagram of the surface temperature of asphalt mixture before and after adding core-shell phase change microspheres in the embodiment of the present application; (a) is the surface temperature of the raw steel slag Marshall specimen, and the surface temperature distribution range of the specimen is 58.1-201.9℃; (b) is the surface temperature of the modified steel slag Marshall specimen of Example 1, and the surface temperature distribution range of the specimen is 56.5-64.8℃. DETAILED DESCRIPTION

[0017] Unless otherwise defined, scientific and technical terms used in this text are understood according to the knowledge of the relevant person in the art.

[0018] It should be explained that the silane coupling agent solution used in the scheme of the present application is a related mixed solution prepared by taking silane coupling agent as solute and organic solvents such as anhydrous ethanol as solvent, and the purpose is to make the silane coupling agent dispersed and fully react with the related object.

[0019] The principles and characteristics of the present application are described below in combination with the drawings, and the examples are only used to explain the present application and are not used to limit the scope of the present application. If the specific conditions are not indicated in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not indicated by the manufacturer, they are all conventional products that can be purchased on the market.

[0020] The asphalt used in the following examples is 90# base asphalt, and its basic properties are shown in Table 1. The tailings used are steel slag from a certain steel plant in Zhengzhou City, Henan Province, which has been aged for more than 12 months. According to the heat output of the steel slag, the steel slag meeting the requirements and having a particle size of 4.75-9.5mm is screened out for standby use. The basic properties of the steel slag and limestone used in the following examples are shown in Table 2, and the mixture gradation composition is as follows Figure 1 The vanadium dioxide used is produced by a certain company in Xi'an City, Shaanxi Province, CAS: 12036-21-4, molecular weight: 165.88, and its basic properties are shown in Table 3.

[0021] Table 1 Basic properties of asphalt

[0022] Table 2 Basic properties of aggregate

[0023] Table 3 Basic properties of vanadium dioxide

[0024] Example 1: The raw materials for preparing the wave-absorbing tailing paint for road use in this example are: 53 g of silica sol, 25 g of silicone resin, 20 g of core-shell phase change microspheres, 1.6 g of nano zinc oxide whiskers, and 0.4 g of hydrophobic association polyacrylic acid sodium. The specific preparation method is: first, the core-shell phase change microspheres and the hydrophobic association polyacrylic acid sodium are added together into deionized water, and then transferred into a planetary ball mill, with zirconium oxide balls as the ball milling medium, and ball milling is carried out at 400 rpm for 5 hours; then, the silica sol, silicone resin, and nano zinc oxide whiskers are mixed uniformly, and then vacuum (the vacuum condition can ensure that the mixed material is fully degassed, i.e., 0.2 MPa in this example) degassing treatment is carried out, and then sealed and aged for 12 hours to obtain the paint. The preparation method of the core-shell phase change microspheres is: The dried 250 g of quartz sand is immersed in 500 g of molten paraffin, and kept at a vacuum degree of 0.2 MPa for 2 hours, then filtered, and the filtrate is discarded, to obtain 300 g of quartz sand loaded with paraffin; The silane coupling agent KH-560 is mixed with anhydrous ethanol (the concentration of the silane coupling agent KH-560 is 1.5 wt%) to obtain a silane coupling agent solution, then 18.8 g of VO2 powder is dispersed in 50 g of the silane coupling agent solution, and after ultrasonic dispersion for 30 minutes, 19.1 g of the VO2 powder modified by the silane coupling agent is obtained after drying. The 300 g of quartz sand loaded with paraffin is dispersed in tetraethyl orthosilicate (the amount of the precursor solvent needs to ensure that the quartz sand loaded with the core material is dispersed, i.e., 500 mL of tetraethyl orthosilicate in this example) and stirred for 4 hours, then the 19.1 g of the VO2 powder modified by the silane coupling agent is stirred for 1.5 hours, and then the core-shell phase change microspheres are obtained after standing and aging for 24 hours, filtering, and drying at room temperature.

[0025] Further, the paint prepared in this example is used to soak the tailing steel slag to prepare a wave-absorbing tailing for road use, and the specific method is: First, the steel slag is preliminarily cleaned with 4 wt% dilute hydrochloric acid (other dilute acids can also be used for cleaning); then it is immersed in anhydrous ethanol solution of 1.5 wt% silane coupling agent KH-560, soaked for 40 minutes, filtered, and the solid material is kept at 300±10°C for 50 minutes under nitrogen protection to obtain the pretreated steel slag. Then, the pretreated steel slag is immersed in the paint for 120 seconds and then filtered; the solid material is kept at room temperature for 20 hours, and then kept at 80±10°C for 2 hours to remove residual solvents and promote crosslinking; finally, the temperature is raised to 180°C under nitrogen protection, and kept for 1.5 hours to complete the curing, to obtain the modified steel slag (also referred to as the wave-absorbing tailing for road use).

[0026] Further, the modified steel slag prepared by the above method is used to prepare a wave-absorbing material for road use: First, the coarse aggregate (coarse aggregate particle size is 2.36-16 mm), fine aggregate (fine aggregate particle size is 0.075-2.36 mm) and modified steel slag (4.75-9.5 mm) are mixed and stirred for 1.5 min, then the base asphalt is added and stirred for 1.5 min, and finally the filler (the filler of this example is limestone powder, particle size less than 0.075 mm) is added and stirred for 1.5 min. The asphalt is 90# base asphalt, the aggregate is limestone aggregate, and the mineral powder is limestone mineral powder. The specific compounding of the mixture of this example is: the gradation is shown in Figure 1 The mixture of this example uses AC-13 gradation, and the gradation curve is median gradation. The modified steel slag of 4.75-9.5 mm is replaced by stone aggregate, which is mixed and designed together with the stone aggregate in the gradation design process. The mass ratio of stone aggregate to modified steel slag is 2.4:1, and the oil-stone ratio is 4.7%.

[0027] Example 2: The difference between this example and Example 1 is that in the preparation of the core-shell phase change microspheres of this example, 95 g of paraffin-loaded quartz sand and 5 g of silane coupling agent-modified VO2 powder are used, and the remaining steps are the same.

[0028] Example 3: The difference between this example and Example 1 is that the raw materials for preparing the coating of this example are: silica sol 58 g, organosilicon resin 22 g, core-shell phase change microspheres 18 g, nano zinc oxide whisker 1.5 g, and hydrophobic association polyacrylic acid sodium 0.5 g. The remaining steps are the same.

[0029] Example 4: The difference between this example and Example 1 is that in the preparation of the road wave-absorbing tailings of this example, 3wt% dilute hydrochloric acid is used to preliminarily clean the steel slag; the cleaned steel slag is soaked with 1wt% silane coupling agent KH-560 ethanol solution, and the remaining steps are the same.

[0030] Comparative Example 1: The difference between this comparative example and Example 1 is that no silica sol is used in the raw materials of the coating, and the remaining steps are the same.

[0031] Comparative Example 2: The difference between this comparative example and Example 1 is that no organosilicon resin is used in the raw materials of the coating, and the remaining steps are the same.

[0032] Comparative Example 3: The difference between this comparative example and Example 1 is that no silica sol and organosilicon resin are used in the raw materials of the coating, and the remaining steps are the same.

[0033] Comparative Example 4: The difference between this comparative example and Example 1 is that no core-shell phase change microspheres are used in the coating raw material, and the remaining steps are the same.

[0034] Comparative Example 5: The difference between this comparative example and Example 1 is that the steel slag without pretreatment and coating soaking treatment (i.e., the steel slag raw material) is used, and the remaining steps are the same.

[0035] Comparative Example 6: The difference between this comparative example and Example 1 is that 20 g of core-shell phase change microspheres is replaced by 18.8 g of V02 powder during the preparation of the coating, and the remaining steps remain unchanged.

[0036] Comparative Example 7: This comparative example is based on Comparative Example 6, and an ultrasonic dispersion method is used before ball milling to increase the dispersion of V02 and avoid its agglomeration, and the remaining steps remain unchanged.

[0037] According to the “Highway Engineering Asphalt and Asphalt Mixture Test Procedures” (JTG 3410-2025), the above examples and comparative examples are subjected to semi-circular bending test and microwave heating healing cycle test and road performance detection. Among them: Semi-circular bending test and microwave heating healing cycle test: first, cut the formed Marshall cylindrical test piece into SCB test piece, and place the cold-treated test piece in a -10℃ environment for 6h; then install it on a universal testing machine for loading test, and record the maximum breaking load P0(kN) of the test piece; then use a microwave device with a frequency of 2.45GHz and a power of 700W to heat the SCB cracked test piece for 120s to promote the healing reaction of the cracked mixture; then continue to place the test piece in a -10℃ environment for 6h until the state is stable, and then perform SCB loading test again, and record the maximum breaking load P(kN) at this time; finally, the residual strength ratio of the mixture is obtained by calculating the ratio of P to P0. The above process constitutes a complete test cycle, and the cycle is repeated until the predetermined test number. The results are shown in Table 4.

[0038] Road performance detection: according to the specification requirements of “Highway Engineering Asphalt and Asphalt Mixture Test Procedures” (JTG 3410-2025), high temperature stability, low temperature crack resistance and water stability tests are carried out on the asphalt mixture test pieces of the examples and comparative examples, and the specific test results are shown in Table 5.

[0039] The surface temperature of the Marshall test piece after microwave heating is tested by using a Fluke TiS75 infrared temperature measuring instrument; then the collected infrared thermal image is imported into the SmartView PC terminal software for data analysis, the effective area of the test piece surface is framed by the elliptical lasso tool to exclude background interference, the hot cursor and cold cursor in the display marker function of the software are used to read and display the specific temperature value of the area, and finally the maximum temperature difference of the test piece is counted. Fig. 2 is the surface temperature analysis result of the Marshall test piece prepared from the modified steel slag of Example 1 (after 1 time of microwave heating) and the Marshall test piece prepared from the initial steel slag (after 1 time of microwave heating), and the result shown in Fig. 2 shows that the highest temperature of the surface of the modified steel slag asphalt mixture is 64.8℃, and the maximum temperature difference is 8.4℃, which is more uniform than the surface temperature of the unmodified steel slag test piece.

[0040] Table 4 Test results of cycle SCB test

[0041] Table 5 Test results of road performance

[0042] It can be seen from the test results that: referring to the effects of Examples 1-4 and Comparative Examples 1-7, after coating the surface of the steel slag, the road performance of the asphalt mixture meets the specification requirements and is maintained at a relatively optimal level.

[0043] Through comparative analysis of Examples 1-4 and Comparative Examples 1-7, it is found that Example 1 of the present application has obvious advantages in strength retention, temperature uniformity, cycle stability and road performance. At the same time, the effects of the comparative examples show that: the silica sol plays an obvious advantage in improving the strength residual rate of the coating, the uniformity of temperature control and high temperature stability; the addition of the organosilicon resin obviously improves the strength residual, the maximum temperature deviation control and the low temperature crack resistance; the mixed incorporation of the organosilicon resin and the silica sol obviously improves the overall strength and road performance; the core-shell phase change microspheres have obvious advantages in controlling the maximum temperature deviation; the coating of the present application for the wrapping treatment of the wave-absorbing tailings has a significant effect on reducing the maximum temperature deviation, improving the strength residual rate and road performance, and among them, the core-shell phase change microspheres have a significant advantage in improving the uniformity of VO2 dispersion.

[0044] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A road wave-absorbing tailings paint, characterized by, The preparation raw materials of the coating include: 45-60 parts by mass of silica sol, 20-30 parts by mass of silicone resin, 18-22 parts by mass of core-shell phase change microspheres, 1.5-2.5 parts by mass of nano zinc oxide whiskers, and 0.3-0.6 parts by mass of hydrophobic association sodium polyacrylate; The preparation method of the core-shell phase change microspheres comprises the following steps: dispersing quartz sand loaded with a core material in a precursor solvent, uniformly mixing, adding silane coupling agent modified VO2 powder, continuously uniformly mixing, standing and aging, filtering, and drying to obtain the core-shell phase change microspheres; The preparation method of the quartz sand loaded with the core material comprises the following steps: soaking quartz sand in molten organic phase change core material, and then filtering and collecting the solid to obtain the quartz sand loaded with the core material; the organic phase change core material is selected from paraffin or fatty acid; The precursor solvent is selected from tetraethyl orthosilicate or aluminum isopropyl alcohol; The preparation method of the silane coupling agent modified VO2 powder comprises the following steps: dispersing VO2 powder in a silane coupling agent solution, uniformly mixing, and drying to obtain the silane coupling agent modified VO2 powder; The mass ratio of the quartz sand to the VO2 powder is (10-20):

1.

2. The wave-absorbing tailings paint for road use according to claim 1, characterized by, The mass ratio of the organic phase change core material to the quartz sand is (1.5-2.5):

1.

3. The wave-absorbing tailings paint for road use according to claim 1, characterized by, The mass ratio of the VO2 powder to the silane coupling agent is (20-100):

1.

4. The wave-absorbing tailings paint for road use according to claim 1, characterized by, The preparation of the quartz sand loaded with the core material is carried out under the condition of 0.1-0.3 MPa.

5. The wave-absorbing tailings paint for road use according to claim 1, characterized by, The preparation method of the coating comprises the following steps: firstly, ball-milling and mixing core-shell phase change microspheres and hydrophobic association sodium polyacrylate; then, adding silica sol, silicone resin and nano zinc oxide whiskers, uniformly mixing, and placing under vacuum conditions for defoaming treatment; and finally, standing and aging to obtain the coating.

6. A road wave-absorbing tailings, comprising a base tailings, the base tailings being magnetite or steel slag, characterized in that, The road wave-absorbing tailings are obtained by soaking base tailings in the coating according to any one of claims 1-5.

7. The road wave-absorbing tailings of claim 6, wherein, The preparation method of the road wave-absorbing tailings comprises the following steps: soaking tailings after acid washing in a silane coupling agent solution, then standing and aging the soaked tailings under the condition of room temperature-400 DEG C to obtain pretreated tailings; then, soaking the pretreated tailings in the coating, filtering and collecting the solid material, and standing and curing the solid material under the condition of room temperature-200 DEG C to obtain the road wave-absorbing tailings.

8. The road wave-absorbing tailings of claim 7, wherein, The preparation method of the road wave-absorbing tailings comprises the following steps: soaking tailings after acid washing in a silane coupling agent solution, then standing and aging the soaked tailings under the condition of room temperature-400 DEG C to obtain pretreated tailings; then, soaking the pretreated tailings in the coating, filtering and collecting the solid material, and standing and curing the solid material under the condition of room temperature-200 DEG C to obtain the road wave-absorbing tailings.

9. The wave-absorbing tailings for road use according to claim 7 or 8, characterized in that, The curing process is carried out in stages.

10. A road wave-absorbing material, the raw material for the preparation of the road wave-absorbing material comprising aggregate, filler and asphalt, characterized in that, The preparation raw materials of the road wave-absorbing material further comprise the road wave-absorbing tailings according to claim 7.

Images