CN-120965200-B - Light concrete wave-absorbing material based on carbon-based magnetic material and preparation method thereof

CN120965200BCN 120965200 BCN120965200 BCN 120965200BCN-120965200-B

Abstract

The invention discloses a lightweight concrete wave-absorbing material based on carbon-based magnetic material and a preparation method thereof, relating to the technical field of lightweight building materials, wherein natural plant fiber is used for replacing conductive carbon black, graphene, carbon nano tube and other materials in the traditional carbon-based magnetic material, after instant carbonization by high-voltage electricity, natural plant fiber forms carbonized fiber venation, the carbonized conductive wave-absorbing performance is different from that of the traditional carbon material, and because the length of the plant fiber is longer, the cross-linking property is good, the overall conductivity of the material is far higher than that of the traditional carbon material, a large amount of fiber veins which are not contacted originally are broken down and communicated under the action of current, the conductivity of the material is further enhanced, meanwhile, the magnetic phase attached to the surface of the plant fiber is fused with the carbonized fiber veins under the action of current, the conductivity and the magnetic conductivity of the material are further improved, the electric loss and the magnetic loss of the material to electromagnetic waves are increased, the wave absorbing performance of the material is improved, and the production cost is reduced.

Inventors

HU QINGJIANG
LUO HUI
Tian chenghua

Assignees

南通盛和益新材料科技有限公司

Dates

Publication Date: 20260512
Application Date: 20250904

Claims (8)

1. The preparation method of the lightweight concrete wave-absorbing material based on the carbon-based magnetic material is characterized in that the wave-absorbing material consists of the carbon-based magnetic material and an aerated concrete substrate, the carbon-based magnetic material consists of the magnetic material and a dielectric carbon material, the magnetic material is made of magnetic material powder, the dielectric carbon material is made of plant fibers through high-voltage electric instant carbonization treatment, the magnetic material and the dielectric carbon material are 1-5 parts by weight of the magnetic material and 20-100 parts by weight of the dielectric carbon material, the aerated concrete substrate is made of, by weight, 10-15 parts by weight of cement, 60-70 parts by weight of fly ash, 15-20 parts by weight of quicklime, 0.5-1 parts by weight of aluminum powder and 50-60 parts by weight of water, the granularity of the aluminum powder is selected between 100 meshes and 325 meshes, and the preparation method comprises the following steps: S1, premixing a carbon-based magnetic material, wherein the magnetic material is Mn-ZnFe 2 O 4 , the plant fiber is long staple cotton fiber, the magnetic material powder is uniformly sprayed on the plant fiber in a form of tiny liquid drops by adopting a spray drying method, and then adsorption is promoted by mechanical stirring, and the premixing time is controlled to be 5-10 minutes; S2, stirring the aerated concrete, namely firstly preparing cement, fly ash, quicklime, aluminum powder and water, then mixing according to a designed proportion, pouring into a stirrer, and uniformly stirring; S3, adding the carbon-based magnetic material, namely continuously adding the premixed carbon-based magnetic material after uniformly stirring the concrete, and continuously stirring the mixture at the same time to ensure that the carbon-based magnetic material and the concrete are fully and uniformly mixed, and continuously stirring for 5-10 minutes after the carbon-based magnetic material is added; s4, pouring, namely coating a release agent on the surface of the die in advance, and then pouring the uniformly mixed concrete material into the die, wherein the uniform speed is maintained in the pouring process; S5, standing and foaming, namely placing the mould in a stable environment for standing for 24 hours, so that aluminum powder reacts with water to generate hydrogen, a uniform bubble structure is formed in the concrete, and in the standing process, supplementing moisture according to air temperature and humidity to keep the surface of the concrete moist; S6, surface planing, namely planing the upper surface and the lower surface of the aerated concrete block after the concrete is solidified, so that plant fibers in the concrete are exposed, and the planing depth is 2-5 mm; S7, electric tissue carbonization, namely soaking the solidified concrete, uniformly arranging electrodes on the upper and lower surfaces of the ground concrete, electrifying the ground concrete at an electrode distance of 5-10 cm, carbonizing plant fibers by using instantaneous high-voltage current, ensuring ventilation in the carbonization process so as to discharge gas generated by carbonizing the plant fibers, monitoring temperature change and preventing the structure from being damaged by overheating.
2. The method for preparing lightweight concrete wave-absorbing material based on carbon-based magnetic material as set forth in claim 1, wherein in S1, the purity of the magnetic material used is greater than 99%, and the magnetic material is ground before premixing the carbon-based magnetic material so that the granularity of the magnetic material is less than 100 mesh.
3. The method for preparing lightweight concrete wave-absorbing material based on carbon-based magnetic material as set forth in claim 1, wherein in S1, vegetable fibers are finely combed by a carding machine before premixing, and the aggregated fiber clusters are combed into single fibers while larger fiber impurities are removed.
4. The method for preparing the lightweight concrete wave-absorbing material based on the carbon-based magnetic material according to claim 1, wherein in the step S1, the method for spraying the magnetic material powder on the plant fiber by spray drying comprises the following steps: S401, preparing a magnetic material suspension, namely mixing magnetic material powder with water to prepare a suspension, and fully stirring by using a stirrer to ensure that the magnetic material is uniformly dispersed in the liquid; s402, adjusting spraying parameters, namely adjusting parameters of a sprayer, including spraying pressure, flow and spraying angle, according to the characteristics of the magnetic material suspension and the properties of plant fibers; S403, preheating a drying chamber, namely starting a hot air system, preheating the temperature of the drying chamber to a preset value, and determining the temperature according to the heat sensitivity of the magnetic material and the plant fiber; S404, spray drying, namely delivering the prepared magnetic material suspension into a sprayer, then starting the sprayer to uniformly spray the suspension into a drying chamber in the form of tiny liquid drops, enabling hot air to enter from the bottom of the drying chamber, enabling the hot air to contact with the mist drops in a countercurrent manner, and rapidly evaporating the liquid to uniformly attach the magnetic material powder to plant fibers.
5. The method for preparing the lightweight concrete wave-absorbing material based on the carbon-based magnetic material as set forth in claim 1, wherein the process of stirring the aerated concrete in S2 comprises the following steps: S701, preparing cement by raw materials, namely selecting ordinary Portland cement with the strength grade not lower than 42.5, selecting fly ash with the grade II or above, the fineness of the fly ash is less than 45 mu m, the loss on ignition is less than 5%, quick lime with the effective calcium oxide content of more than 70% and the fineness of the quick lime is less than 10mm, aluminum powder with the purity of more than 90% and the fineness of the quick lime of less than 45 mu m, and clean fresh water with the pH value of 6-8; s702, weighing 10-15 parts of cement, 60-70 parts of fly ash, 15-20 parts of quicklime, 0.5-1 part of aluminum powder and 50-60 parts of water according to parts by weight; S703, mixing raw materials, namely pouring cement, fly ash and quicklime into a stirrer, dry-mixing for 1-2 minutes, then adding aluminum powder, and continuing dry-mixing for 1-2 minutes to uniformly distribute the aluminum powder in the cement, the fly ash and the quicklime; s704, stirring the concrete, namely adding water into the mixed dry materials, and starting stirring, wherein the stirring time is controlled to be 3-5 minutes.
6. The method for preparing the lightweight concrete wave-absorbing material based on the carbon-based magnetic material of claim 1, wherein when the carbon-based magnetic material is added in the step S3, the carbon-based magnetic material is added in batches according to the upper surface area of the aerated concrete in the mixer, so that the carbon-based magnetic material added each time is loosely covered on the surface of the aerated concrete, the single covering thickness is smaller than 5mm, the thickness is ensured to be uniform and free from accumulation, and the mixing is continued for 2-3 minutes after the carbon-based magnetic material is added each time.
7. The method for preparing the lightweight concrete wave-absorbing material based on the carbon-based magnetic material according to claim 1, wherein in the step S5, the ambient temperature is controlled to be 20-30 ℃ and the relative humidity is controlled to be 60-80% when the concrete is subjected to standing foaming.
8. The method for preparing the lightweight concrete wave-absorbing material based on the carbon-based magnetic material according to claim 1, wherein the power supply adopts high-voltage direct current when electric tissue carbonization is carried out in the step S7, and the control voltage is between 3kV and 5kV, and the duration time is within 0.3S.

Description

Light concrete wave-absorbing material based on carbon-based magnetic material and preparation method thereof Technical Field The invention relates to the technical field of wave-absorbing materials, in particular to a light concrete wave-absorbing material based on a carbon-based magnetic material and a preparation method thereof. Background Along with the continuous development of modern science and technology, the wave absorbing material is increasingly widely applied in the fields of military, electronics, communication and the like, and the traditional wave absorbing material has certain wave absorbing performance, but the traditional wave absorbing material has the defects of high density, heavy weight, difficult processing and the like, so that the application range is limited, therefore, the developed light, high-strength and easy-processing wave absorbing material becomes one of hot spots in the current material science field, and the carbon-based magnetic material is taken as a novel wave absorbing material, has the advantages of light, high strength, high efficiency wave absorbing, good stability and the like due to the excellent performances of light, high conductivity, high magnetic conductivity and the like, receives extensive attention, and can be combined with aerated light and lightweight concrete. The existing carbon components in the carbon-based magnetic material are usually conductive carbon black, graphene, carbon nano tubes and other materials, the cost of the materials is high, the structure of the materials is usually fragile, the fiber structure of the materials is damaged when the materials are mixed with concrete, the fibers are too short, the fibers are less in contact after being wrapped by the concrete, the conductive phases in the concrete are not smooth, the wave absorbing effect of the materials is affected, the wave absorbing performance of the materials can only be improved by improving the adding proportion of the carbon-based magnetic material, but the cost of the materials is high. Disclosure of Invention The invention aims to provide a lightweight concrete wave-absorbing material based on a carbon-based magnetic material and a preparation method thereof, so as to solve the problem that the continuity of a conductive phase in the traditional wave-absorbing material is poor. In order to achieve the above purpose, the present invention provides the following technical solutions: the lightweight concrete wave absorbing material based on the carbon-based magnetic material consists of 1-5 parts by weight of the magnetic material and 20-100 parts by weight of the dielectric carbon material, wherein the carbon-based magnetic material consists of magnetic material and dielectric carbon material; The aerated concrete substrate is prepared from, by weight, 10-15 parts of cement, 60-70 parts of fly ash, 15-20 parts of quicklime, 0.5-1 part of aluminum powder and 50-60 parts of water. Further, the particle size of the aluminum powder is selected to be between 100 mesh and 325 mesh, that is, the particle diameter of the aluminum powder is between about 150 microns and 45 microns, and the particle size in this range can provide better reactivity and foaming effect, and the particle size distribution of the aluminum powder is as uniform as possible, so that too large or too small particles are avoided, as this will affect the uniformity and stability of foaming. The invention provides another technical scheme that the preparation method of the lightweight concrete wave-absorbing material based on the carbon-based magnetic material comprises the following steps: s1, premixing a carbon-based magnetic material, namely selecting a magnetic material with high magnetic conductivity and good dispersibility, comprising Mn-ZnFe 2O4, selecting light and high-strength plant fibers, comprising long-staple cotton fibers, uniformly spraying magnetic material powder on the plant fibers in a micro-droplet form by adopting a spray drying method, and then promoting adsorption by mechanical stirring, wherein the premixing time is controlled between 5 and 10 minutes, so that uniform mixing is ensured; S2, stirring the aerated concrete, namely firstly preparing cement, fly ash, quicklime, aluminum powder and water, then mixing according to a designed proportion, pouring into a stirrer, and uniformly stirring; S3, adding the carbon-based magnetic material, namely continuously adding the premixed carbon-based magnetic material after uniformly stirring the concrete, and continuously stirring the carbon-based magnetic material to ensure that the carbon-based magnetic material and the concrete are fully and uniformly mixed, and continuously stirring for 5-10 minutes after the carbon-based magnetic material is added, so that uniform material distribution is ensured; s4, pouring, namely coating a release agent on the surface of the die in advance, and then pouring the uniformly mixed concrete material into the