Microwave absorption enhancer and preparation method and application thereof

Abstract

The invention discloses a microwave absorption enhancer and a preparation method and application thereof. The microwave absorption enhancer is road stones with a layer of nano Fe3O4 magnetic materialadhered on the surfaces, wherein the mass fraction of the nano Fe3O4 magnetic material is 5 to 15%. The preparation method comprises the following steps: (1) dissolving ferrous salt and iron salt in distilled water to respectively prepare a solution with the concentration of 0.5 to 10mol / L; (2) sequentially spraying the ferrous salt solution, the iron salt solution and ammonium hydroxide onto thesurfaces of road stones in the molar ratio of Fe<2+> to Fe<3+> to OH<-> being equal to 1 to (1.6 to 2) to (8 to 16) under oxygen insulation environment, and then heating and stirring for 20 to 30 minutes; (3) placing the road stones subjected to the surface reaction into an oven at 50 DEG C to 70 DEG C, heating until being completely dried; (4) heating the dried stones to 80 DEG C to decompose andremove reaction residues to obtain the microwave absorption enhancer. By adding some or all of the microwave absorption enhancer to an asphalt mixture instead of ordinary aggregates, the microwave heating rate and the microwave energy utilization rate of the asphalt mixture can be significantly increased.

Description

technical field [0001] The invention relates to a microwave absorption enhancer, a preparation method of the microwave absorption enhancer and its application in asphalt mixture, belonging to asphalt pavement heating technology. Background technique [0002] As we all know, asphalt pavement heating technology is widely used in pavement maintenance, regeneration, snow melting and deicing and other fields. The commonly used heating technologies include hot air heating, infrared heating and microwave heating. Among them, microwave heating makes the heated object Heating, which belongs to volume heating, has the advantages of deep heating, small thermal inertia, and easy control. It is especially suitable for heating asphalt mixture with poor thermal conductivity. It is the main research object in current pavement heating technology. [0003] The microwave absorption capacity of asphalt mixture is mainly derived from aggregates, but general aggregates are not strong enough to ab...

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Problems solved by technology

However, there are obvious defects in the direct incorporation method. Adding wave-absorbing powder instead of mineral powder into the mixture is not only costly, but also easily leads to problems such as agglomeration and uneven dispersion of wave-absorbing powder during the stirring process. This will lead to uneven heating of the pavement; adding magnetite, steel slag and other wave-absorbing particles into the mixture instead of coarse and fine aggregates will affect the road performance of the asphalt mixture to a certain extent; Modified asphalt obtained by mixing body or fiber with asphalt, although the microwave absorption capacity is improved, but it is prone to problems such as uneven dispersion and precipitation of microwave-absorbing materials in the process of preparation and storage, and the types of asphalt used for different roads are different. In engineering applications, it is necessary to modify the corresponding asphalt, which is extremely inconvenient

[0004] In the Chinese invention patent with the application number "201610410532.1" and the title "A Asphalt Pavement Material That Can Be Quickly Repaired Using Microwave Heating", a modified steel slag aggregate that can enhance the microwave absorption efficiency of asphalt pavement is disclosed. Chemically remove the Fe on the surface of steel slag 2 o 3 converted to magnetic Fe 3 o 4 , further enhanced the microwave absorption capacity of steel slag, used in asphalt pavement can not only enhance the microwave heating efficiency of the pavement, but also provide a new way for the recycling of steel slag waste, but the iron contained in ordinary steel slag itself 2 o 3 Only about 20% of the Fe on the surface participates in the reaction 2 o 3 less, the Fe generated on the surface of the modified steel slag 3 o 4 It is very limited, and the steel slag itself participates in the chemical reaction, and its mechanical properties such as the strength of the aggregate are bound to be affected. In addition, considering the possibility of steel slag expansion, the amount of this modified steel slag should not be too large, and the steel slag itself will also Microwaves with more loss, microwave utilization and heat transfer efficiency are still not high

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