CN114105659A

CN114105659A - Nano Al2O3-SiC composite powder, low-carbon pouring ladle slide plate brick and preparation method thereof

Info

Publication number: CN114105659A
Application number: CN202111611715.7A
Authority: CN
Inventors: 周亮; 徐昆波; 方岩震; 余西平; 赵锋
Original assignee: Maanshan Lier Kaiyuan New Material Co ltd
Current assignee: Maanshan Lier Kaiyuan New Material Co ltd
Priority date: 2021-12-27
Filing date: 2021-12-27
Publication date: 2022-03-01
Anticipated expiration: 2041-12-27
Also published as: CN114105659B

Abstract

The invention discloses a nano Al₂O₃-SiC composite powder, a low-carbon pouring ladle slide plate brick and a preparation method thereof, belonging to the technical field of refractory materials for ladles. The nano Al₂O₃the-SiC composite powder is prepared by a gas phase method, Al₂O₃Uniformly dispersed on the surface of SiC fine powder, Al₂O₃D50 ═ 13 nm; the low-carbon poured sliding plate brick for steel ladle is added with the prepared nano Al₂O₃the-SiC composite powder is prepared by adopting the processes of multiple dispersion, pouring, multi-stage curing, asphalt impregnation and dry distillation carbonization, the prepared slide brick has high volume density and strength, good high-temperature sintering property, good thermal shock stability and good molten steel and steel slag corrosion resistance, and the service life of the slide brick is prolonged.

Description

Nano Al2O3-SiC composite powder, low-carbon pouring ladle slide plate brick and preparation method thereof

Technical Field

The invention belongs to the technical field of refractory materials for ladles, and particularly relates to nano Al₂O₃-SiC composite powder, a low-carbon pouring ladle slide plate brick and a preparation method thereof.

Background

With the continuous development of steel-making technology, the flow control system in the die casting or continuous casting steel casting process basically adopts a sliding gate flow control system to replace a stopper rod flow control system. The slide plate is used as the most important component part in a sliding nozzle system, the flow of molten steel is directly controlled, and under the condition of meeting different casting process requirements, the slide plate needs to repeatedly bear the chemical erosion and physical scouring of high-temperature molten steel for a long time and simultaneously bears high thermal shock and mechanical abrasion, and the service environment is extremely harsh. The sliding plate brick used at present is basically made of Al₂O₃-C system or Al₂O₃-ZrO₂The system-C is prepared by adopting alumina corundum, zirconia mullite, graphite and the like as main raw materials, mixing the raw materials by taking liquid phenolic resin as a binding agent, then performing high-pressure forming on the mixture by using an electric screw or a hydraulic press to form a green brick, and then performing high-temperature firing; the sliding plate brick produced by the process has a longer flow, needs to be produced under the high-pressure/high-temperature condition, and simultaneously adopts graphite as a carbon source, and more carbon needs to be added, so that the sliding plate brick can be ensured to have certain thermal vibration stability; along with the requirements of smelting of steel of varieties such as clean steel and the like, the influence of refractory materials on molten steel recarburization is required to be reduced as much as possible, so that the sliding plate brick is required to have lower carbon content; meanwhile, under the situation that a steel plant greatly promotes green steel making and intelligent steel making, higher requirements are provided for the use safety, stability and service life of the sliding plate brick used for continuous casting.

Through search, the patent publication number is CN102964138A, the publication date is 3 and 13 months in 2013, and the patent name is light Al₂O₃-SiC-C refractory castable and a preparation method thereof. The refractory castable is prepared from 40-55 wt% of porous corundum particles, 8-12 wt% of corundum particles, 6-12 wt% of SiC particles, 6-10 wt% of SiC fine powder, 5-8 wt% of corundum fine powder, 8-12 wt% of active alumina micropowder, 3-5 wt% of calcium aluminate cement, 2-4 wt% of silica micropowder, 2-4 wt% of spherical asphalt, 1.5-2.0 wt% of silicon powder, 0.1-0.3 wt% of aluminum powder and 0.1-03 wt% of boron carbide powder as a raw material, adding 8-15 wt% of water, 0.2-0.6 wt% of water reducing agent and 0.02-0.04 wt% of organic explosion-proof fiber, stirring, casting, molding, naturally drying, and drying at 110 ℃ for 12-48 hours to obtain the light Al₂O₃-SiC-C refractory castable. The method has the defects that spherical asphalt is used as a carbon source, the direct dispersion and bonding property with binding agent water is poor, C in the casting material cannot be uniformly dispersed between a matrix and a framework, and the erosion resistance and the thermal shock stability of the material are influenced; meanwhile, the porous light refractory castable prepared by the method is suitable for an insulating layer and cannot be directly used for a working layer contacting molten steel. The patent publication No. CN111620706A, published as 2020, 9, month and 4, discloses Al for a modified carbon source optimized blast furnace tapping channel₂O₃the-SiC-C refractory castable is prepared from 55.0-65.0 wt% of brown fused alumina aggregate, 17.0-25.0 wt% of silicon carbide, 8.0-15.0 wt% of active alpha-alumina micropowder, 4.0-6.0 wt% of hydratable alumina, 1.5-2.0 wt% of metal aluminum powder/elemental silicon powder compound antioxidant and 1.5-2.0 wt% of modified carbon source nano-silica composite additive; the Al for the modified carbon source optimized blast furnace tapping channel is prepared by mixing the raw materials and the weight percentage thereof and adding 0.15-0.25 wt% of water reducing agent of the raw materials₂O₃The refractory castable material of-SiC-C has the disadvantages that the refractory castable material cannot be effectively and uniformly dispersed in a castable system after nano silicon dioxide is introduced, and a carbon source introduced by a plant debris combustion mode easily generates some impurity components, so that the erosion resistance of the material is influenced.

In addition, the patent publication No. CN107815625A, publication date 3/2018/20, discloses a SiC continuous fiber reinforced titanium-based composite material, which takes SiC continuous fibers as a base material, and Al is formed by magnetron sputtering₂O₃Sputtering on the surface of the SiC continuous fiber to obtain the Al-coated continuous fiber₂O₃Coated SiC continuous fiber, but the composite material prepared by the method is easy to generate segregation and Al₂O₃The coating is not uniform.

Disclosure of Invention

1. Problems to be solved

Aiming at the existing Al₂O₃Al in sliding brick of-SiC system₂O₃The invention provides nano Al which is difficult to be uniformly mixed with SiC₂O₃-SiC composite powder and preparation method thereof, and nano Al prepared by gas phase method₂O₃And composite powder uniformly dispersed on the surface of the SiC fine powder.

The invention provides a low-carbon pouring ladle slide plate brick and a preparation method thereof, and the prepared nano Al is added₂O₃The sliding brick prepared from the-SiC composite powder has high volume density and strength, good high-temperature sintering property, good thermal shock stability and good molten steel and steel slag corrosion resistance, and the service life of the sliding brick is prolonged.

2. Technical scheme

In order to solve the problems, the technical scheme adopted by the invention is as follows:

nano Al₂O₃-SiC composite powder of said Al₂O₃Uniformly dispersed on the surface of SiC fine powder, Al₂O₃D50 ═ 13nm, BET specific surface area 100. + -. 15m²/g，Al₂O₃The content is more than or equal to 99.5 percent, and the pH value is 5-6. The weakly acidic environment can lead the nano Al₂O₃A certain electrostatic repulsion force is obtained by a small number of medium-sized particles with positive charges, so that the secondary aggregation of the nano particles after gas phase high-speed dispersion is avoided, and the uniformity and stability of the composite powder are improved.

Further, the Al₂O₃The weight ratio of the SiC fine powder to the SiC fine powder is (20-40%): (60% to 80%) of the above Al₂O₃The sum of the weight proportion of the fine powder and the SiC powder is 100 percent.

Furthermore, the SiC fine powder is a mixture of black silicon carbide and green silicon carbide, and is in an alpha-SiC crystal form, wherein the mass content of the black silicon carbide is 70%, the mass content of the green silicon carbide is 30%, the SiC content in the black silicon carbide is more than or equal to 97%, the particle size is 0-0.074 mm, the SiC content in the green silicon carbide is more than or equal to 98%, the particle size is 0-0.045 mm, the surface activity of the black silicon carbide is high, and nano Al is favorably distributed on the surface of the black silicon carbide₂O₃Adsorption and coating, green carbonizationThe silicon has higher purity, lower impurity content and higher hardness and mechanical strength, and is beneficial to nano Al by adding the mixture of black silicon carbide and green silicon carbide₂O₃The adsorption is uniformly dispersed, and the high-temperature strength, the mechanical strength and the oxidation resistance of the sliding plate brick are improved.

The nano Al₂O₃the-SiC composite powder is produced by adopting a gas phase method, and the method comprises the following steps:

(1) preparing materials: mixing Al₂O₃Weighing the SiC fine powder according to the proportion;

(2) mixing materials: mixing the above Al₂O₃Putting the SiC fine powder and the high-speed airflow impact type mixer into a mixing machine for mixing, wherein preliminary mixing is carried out for 3-5 min, and the rotating speed of a main machine is 100-200 rpm; mixing materials at a high speed for 20-30 min, wherein the rotating speed of a main machine is 800-1200 rpm; further mixing the materials for 3min, wherein the rotating speed of the main machine is more than or equal to 1200 rpm.

The invention firstly prepares nano Al₂O₃-SiC composite powder, compared with Al which is not used in the prior art₂O₃The agglomeration phenomenon of particles generated by premixing with SiC influences the dispersibility of the components, the Al of the invention₂O₃Uniformly coated on the surface of SiC fine powder, in addition, the nano Al of the invention₂O₃the-SiC composite powder is prepared by a gas phase method, and the nano Al is prepared by using a high-speed airflow impact type mixer and utilizing the high-speed rotation of a main machine rotor and the strong impact force of the high-speed airflow generated by the high-speed airflow on particles₂O₃After fully dispersing the particles, embedding the particles into the surface of the SiC particles and fixing the particles so that the alumina particles and the silicon carbide particles are tightly adsorbed together; meanwhile, under the action of impact force, silicon carbide particles with partial defects can be ground into spherical or nearly spherical particles, so that the compact packing performance of the composite powder is improved. Compared with the composite material prepared by magnetron sputtering by using SiC fiber as a substrate, the particles prepared by the vapor phase method have Al₂O₃Uniform distribution, SiC and Al in the preparation process₂O₃Is in a dynamic state under the impact of airflow, avoids the phenomenon of Al₂O₃And the density difference of SiC.

The invention also discloses a low-carbon pouring steel ladle sliding plate brick which comprises a granular material and fine powder, wherein the granular material comprises 5-10% of corundum particles with the particle size of 5-3 mm, 28-35% of corundum particles with the particle size of 3-1 mm and 20-25% of corundum particles with the particle size of 1-0 mm according to mass percentage; the fine powder comprises 10-16% of corundum fine powder with the particle size of 0-0.045 mm, 5-8% of fused magnesia fine powder with the particle size of 0-0.074 mm, and nano Al in percentage by mass₂O₃3 to 5 percent of-SiC composite powder and active alpha-Al₂O₃6-10% of micro powder, 5-8% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage of the granular material and the fine powder material is 100%; water accounting for 4 to 5 percent of the total weight is added.

The vapor phase method of the invention prepares the nanoscale Al₂O₃The high-purity castable has high purity, good dispersibility and high specific surface area and specific surface energy, greatly improves the fluidity of the castable, promotes the high-temperature sintering property of the sliding plate brick, and increases the volume density and strength of the sliding plate brick; at the same time, nano-scale Al₂O₃Nanometer micropores can be generated in the casting material, so that the increase of the internal stress of the sliding plate brick caused by external force is gradually absorbed in the use process of the sliding plate brick, the sliding plate brick is prevented from cracking caused by stress extension, and the thermal shock stability of the sliding plate brick is improved; the SiC fine powder has high strength, and when the SiC fine powder is added into the sliding plate brick, the high-temperature strength and the high-temperature rupture strength of the sliding plate brick are improved, and simultaneously, the SiC fine powder and the nano Al coated on the surface of the sliding plate brick at high temperature₂O₃And (3) reacting, namely producing a mullite crystal body in situ, filling the mullite crystal body in nano-scale and micro-scale air holes in the sliding plate brick, and improving the compactness, the high-temperature thermal shock stability and the molten steel and steel slag erosion resistance of the sliding plate brick, thereby prolonging the service life of the sliding plate brick.

Furthermore, the corundum particles and the corundum fine powder are one or more than one of sintered plate-shaped corundum, fused white corundum and fused brown corundum; the fused white corundum and the fused brown corundum are formed by recrystallization after being melted by an electric arc furnace at the temperature of more than 2100 ℃, and the obtained corundum has good crystallinity, high wear resistance, high strength and good compactness; high temperature calcined tabular corundum gasThe corundum prepared by the two different processes is used as the aggregate of the sliding plate brick, so that the high-temperature strength, the high-temperature chemical stability, the thermal shock stability and the service life of the sliding plate brick can be improved; al of sintered plate-like corundum and fused white corundum₂O₃The content is more than or equal to 99.3 percent, and the content R of the alkaline oxide₂O is less than or equal to 0.25 percent, R is K or Na, and the volume density is more than or equal to 3.55g/cm³(ii) a Al of fused brown corundum₂O₃The content is more than or equal to 95.8 percent, and TiO₂The content is less than or equal to 3 percent, SiO₂The content is less than or equal to 1.5 percent, and the volume density is more than or equal to 3.60g/cm³。

Furthermore, the MgO content of the fused magnesia fine powder is more than or equal to 98.2 percent, and the SiO content of the fused magnesia fine powder₂The content is less than or equal to 0.9 percent, and the volume density is more than or equal to 3.50g/cm³。

Further, the active α -Al₂O₃The micro powder is high-temperature calcined bimodal Al₂O₃Micropowder, typical D50 bimodal 0.8 μm and 2.7 μm, Al₂O₃The content is more than or equal to 99 percent.

Furthermore, the composite binder is a composite of calcium aluminate cement, silicon micropowder and hydraulic alumina, and is prepared by uniformly mixing the calcium aluminate cement, the silicon micropowder and the hydraulic alumina, wherein the mass ratio of the calcium aluminate cement to the silicon micropowder to the hydraulic alumina is (1-2): (4-5): (3-4).

Further, the calcium aluminate cement is CA-80 cement, wherein Al₂O₃The content is more than or equal to 76.5 percent, and the content of CaO is less than or equal to 22.5 percent; SiO in the silicon micro powder₂The content is more than or equal to 94.5 percent, and typical D50 is 0.15 mu m; the hydraulic alumina main crystal phase is rho-Al₂O₃，ρ-Al₂O₃The content is more than or equal to 99 percent.

The low-carbon pouring ladle slide plate brick is compounded by calcium aluminate cement, silica powder and hydraulic alumina in a reasonable ratio to serve as a binding agent of the pouring slide plate brick; calcium aluminate cement of about 4 percent is added into the corundum castable conventionally as a binding agent, the early strength of the slide plate brick is high, and a hydration product continuously grows and grows up in the curing process and forms cementing particlesThe crystal-gel three-dimensional grid structure connects the aggregate parts in the slide plate brick to form certain strength; when the addition amount of the cement is higher, the high-temperature strength and the erosion resistance of the sliding plate brick are reduced by the anorthite and the anorthite with low melting points formed at the high temperature of CaO; the micron-sized silicon micropowder has obvious spherical particles, colloid particles formed in water cover the surfaces of skeleton particles, the agglomeration phenomenon among the particles is prevented, the fluidity of the castable is improved, and simultaneously, hydrated silanol groups are dehydrated and condensed to form a firm three-dimensional space network structure combined by-Si-O-Si in a maintenance stage, so that the temperature can be kept to be more than 1200 ℃, and the network structure can obviously improve the normal temperature strength and the medium temperature strength of the castable; with rho-Al₂O₃Hydraulic alumina with predominant crystalline phase, converted to high temperature stable phase alpha-Al at high temperature₂O₃And is easily reacted with SiO₂The MgO reacts in situ to generate mullite and spinel which have high melting point and are corrosion resistant, so that the strength, slag resistance and service performance of the castable are improved, and the excessive addition of the hydraulic alumina can increase the water addition of the castable and influence the high-temperature strength of the sliding plate brick; the sliding plate brick prepared by reasonably combining the addition amounts of the three binding agents and selecting the CA-80 calcium aluminate cement with low CaO content has high strength and erosion resistance at low temperature, medium temperature and high temperature.

Furthermore, the water reducing agent is one or more than one of sodium tripolyphosphate and polyethylene glycol group, can be used alone, or can be a mixture of the sodium tripolyphosphate and the polyethylene glycol group, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol group in the mixture is 5: 5, when a mixture of sodium tripolyphosphate and polyethylene glycol groups is used as a water reducing agent, the sodium tripolyphosphate is dissociated into macromolecular anions in water and is adsorbed on the surfaces of the micro-powder particles, a diffusion double electric layer is formed on the surfaces of the particles, a flocculation structure in a system is damaged and inhibited, so that free water in the system is increased, and the fluidity of the casting material is improved; the polyethylene glycol water reducing agent containing a large amount of hydrophilic functional groups such as carboxyl, carboxylate, hydroxyl and the like forms a thicker polymer molecule adsorption layer on the surface of the particles, and when the particles approach each other to the adsorption layer to generate overlapping, a stronger steric hindrance repulsion effect is generated, so that the fluidity of the casting material is improved; according to the invention, through the composite action of the two water reducing agents, the electrostatic repulsion effect and the steric hindrance effect of ions in the water reducing agents after being dissolved in water are reasonably utilized, the fluidity of the castable is effectively improved, and the water adding amount is reduced.

Furthermore, the explosion-proof agent is one or more than one of aluminum fibers and polypropylene fibers, can be used alone, and can also be a mixture of the aluminum fibers and the polypropylene fibers, and the mass ratio of the aluminum fibers to the polypropylene fibers in the mixture is 7: 3, when the mixture of the aluminum fiber and the polypropylene fiber is used as the explosion-proof agent, the aluminum fiber can slowly react with water to generate a certain amount of H in the processes of pouring and primary maintenance of the sliding brick, namely, the aluminum fiber, the metal aluminum atoms with the surface activity of the fiber₂Gas is discharged, tiny pore canals are formed in the slide plate brick to facilitate the removal of water vapor, and simultaneously, fibrous metal aluminum is uniformly distributed in the slide plate brick and can react with C, N and the like in the slide plate brick at high temperature to generate Al₄C₃Non-oxides of ceramic phases such as AlN are uniformly distributed and crossed in the material matrix, so that the strength and toughness of the material are improved, the hot impact force and the thermal stress applied to the sliding plate brick in the high-temperature use process are greatly relieved, and the high-temperature breaking strength, the thermal shock stability and the oxidation resistance of the sliding plate brick are improved; the polyethylene glycol is gradually softened, contracted and melted in the secondary maintenance process of the sliding plate brick, and finally forms air holes and is carbonized, tiny network air holes are formed in the sliding plate brick, a water vapor discharge channel is opened, the internal stress is reduced, and the sliding plate brick is prevented from bursting; the aluminum fiber and the polyethylene glycol fiber are used as the composite explosion-proof agent, so that the drainage performance of the sliding plate brick in the pouring process, the primary curing process and the secondary curing process can be effectively improved, the explosion-proof performance is improved, and meanwhile, the high-temperature chemical performance of the sliding plate brick can be effectively improved and the service life of the sliding plate brick is prolonged by adding the aluminum fiber.

The invention discloses a preparation method of the low-carbon pouring ladle slide plate brick, which comprises the following steps:

(1) mixing fine powder: proportionally mixing corundum fine powder with the particle size of 0-0.045 mm, fused magnesia fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder, active alpha-Al₂O₃Mixing the micro powder, the composite binder, the water reducing agent and the explosion-proof agent, wherein the fine powder is mixed on an inclined high-speed mixer for 40-60 min, and the rotating speed of a main machine of the mixer is more than or equal to 400 rpm;

(2) preparing granules: mixing 5-3 mm corundum particles, 3-1 mm corundum particles and 1-0 mm corundum particles according to weight percentage;

(3) mixing the casting materials: mixing and stirring the granules in the step (2), adding the fine powder mixed in the step (1), continuously mixing and grinding, adding water according to a proportion, stirring and discharging, wherein the granules are placed in a vertical shaft planetary stirrer to be dry-mixed for 3-5 min, the rotating speed of a stirrer main machine is more than or equal to 80rpm, adding the fine powder, continuously mixing and grinding for 5-8 min, adding water accounting for 4-5% of the total weight, stirring for 8-10 min, and discharging;

(4) pouring and vibration molding: pouring the mixed castable prepared in the step (3) into a mold twice, and stopping after floating slurry appears on the surface and no bubbles are generated, in the actual operation process, pouring the mixed castable prepared in the step (3) into the mold twice, fixing the mold on a vibration platform through bolts, manually pouring the castable into the mold, then opening the vibration platform, primarily vibrating for 60 seconds, closing the vibration platform, then pouring the other half of the castable, vibrating for 5-8 minutes again, and stopping after floating slurry appears on the surface and no bubbles are generated;

(5) primary maintenance: curing the pouring semi-finished product prepared in the step (4) under a natural ventilation condition, wherein the curing condition is curing for 3-4 hours, then placing the pouring semi-finished product into a constant temperature room at 35-40 ℃ for curing for 6-12 hours, and then placing the pouring semi-finished product into a constant temperature room at 60-70 ℃ for curing for 12-18 hours;

(6) secondary curing: demoulding the primarily cured product, gradually removing fastening screws of the steel template, taking down the poured sliding plate brick, and placing the product in a medium-low temperature kiln for secondary curing, wherein the curing temperature is 280-300 ℃, and the curing time is 24-36 hours;

(7) asphalt impregnation: performing oil immersion treatment on the semi-finished product of the sliding plate brick subjected to secondary maintenance in the step (6), wherein the treatment process is performed in a vacuum oil immersion tank, the asphalt softening point is 70-85 ℃, the temperature in the vacuum tank is 200-250 ℃, the oil immersion pressure maintaining time is more than 6 hours, and the pressure maintaining pressure is more than 2 MPa;

(8) dry distillation and carbonization: sealing the slide plate brick soaked by the asphalt in a gas kiln for dry distillation and carbonization treatment at 850-900 ℃ for 6-8 hours;

(9) finishing treatment: and (4) performing steel hoop beating, double-sided grinding, non-working surface veneering, drying and sliding surface coating treatment on the semi-finished sliding plate brick obtained after the dry distillation carbonization treatment in the step (8), and packaging after the inspection is qualified to obtain the finished sliding plate brick.

The low-carbon pouring ladle slide plate brick is prepared by adopting the processes of multiple dispersion, pouring, multi-stage curing, asphalt impregnation and dry distillation carbonization:

adopting a multiple dispersion process: firstly, nanoscale Al₂O₃Dispersing the fine powder on the surface of the SiC fine powder by using a high-speed airflow impact mixer, fully and uniformly mixing all fine powder raw materials by using an inclined high-speed mixer, uniformly stirring the castable by using a vertical shaft type planetary mixer, and realizing closest accumulation of granular materials (millimeter level), fine powder (micron level), micro powder (submicron level) and ultrafine powder (nanometer level) with different particle sizes in the whole system by using a three-time dispersing process to improve the density of the slide plate brick;

the dry distillation carbonization process after asphalt impregnation is adopted: the well-maintained sliding plate brick is subjected to an asphalt impregnation process, liquid asphalt is impregnated into open pores in the sliding plate brick at high pressure, and then a dry distillation carbonization process is carried out, so that asphalt is decomposed firstly, carbonized and coked, and finally graphitized to form a graphite-shaped carbon net structure which is filled in the pores of the sliding plate brick, and the graphite-shaped carbon net structure, a particle framework and a fine powder matrix form an integral network together, thereby greatly reducing the porosity of the sliding plate brick, improving the volume density and the strength, and meanwhile, the graphitized carbon net structure has good non-wettability with molten steel and steel slag in the use process of the sliding plate brick, and the molten steel and steel slag corrosion resistance of the sliding plate brick can be obviously improved; the carbon source introduced by pitch impregnation and carbonization is uniformly distributed in the sliding plate brick, has low residual content and good anti-corrosion effect, can avoid the defects of nonuniform dispersion, non-wetting carbon and water, easy layering and the like caused by directly introducing the carbon source into the raw materials adopted in the traditional carbon-containing castable, and prolongs the service life of the sliding plate brick.

3. Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

(1) nano Al of the invention₂O₃-SiC composite powder of nano Al₂O₃And SiC fine powder are taken as raw materials, and the nano Al is mixed by a high-speed airflow impact type mixer₂O₃Fully dispersed and wrapped around the SiC fine powder to improve the nano Al₂O₃The dispersibility of the superfine powder;

(2) the low-carbon pouring ladle slide plate brick is added with a certain amount of nano Al₂O₃the-SiC composite powder improves the fluidity of the casting material, promotes the high-temperature sintering property of the sliding plate brick, and increases the volume density and the strength of the sliding plate brick; nano Al₂O₃Nano-scale micropores are generated in the casting material, so that the internal stress of the sliding plate brick is relieved, and the thermal shock stability of the sliding plate brick is improved; the high-strength SiC fine powder improves the high-temperature strength of the sliding brick, and simultaneously the high temperature and the nano Al₂O₃The mullite crystal is produced in situ through reaction, so that the high-temperature thermal shock stability and the molten steel and steel slag corrosion resistance of the sliding plate brick are improved, and the service life is prolonged;

(3) the low-carbon pouring steel ladle sliding plate brick is beneficial to nano Al by adding the mixture of the black silicon carbide and the green silicon carbide₂O₃The adsorption is uniformly dispersed, and the high-temperature strength, the mechanical strength and the oxidation resistance of the sliding plate brick are improved; meanwhile, SiC is used as an antioxidant, and is superior to the reaction of carbon and oxygen at high temperature, so that the oxidation resistance of the sliding plate brick is improved;

(4) the low-carbon pouring steel ladle sliding plate brick takes high-density and high-density electric melting white corundum, electric melting brown corundum and sintered plate-shaped corundum as large-particle aggregates, so that the high-temperature strength, the high-temperature chemical stability and the thermal shock stability of the sliding plate brick are improved; simultaneously, adding a proper amount of corundum fine powder and fused magnesia fine powder, reacting at high temperature to produce a certain amount of in-situ spinel, effectively filling open pores of the sliding plate brick along with the volume increase effect, reducing the porosity of the sliding plate brick and improving the corrosion resistance of molten steel and steel slag;

(5) the low-carbon pouring ladle slide plate brick takes a complex of calcium aluminate cement, silica powder and hydraulic alumina in reasonable proportion as a binding agent for pouring the slide plate brick; by reasonably combining the addition amounts of the three bonding agents and selecting the CA-80 calcium aluminate cement with low CaO content, the prepared slide plate brick has very high strength and erosion resistance at low temperature, medium temperature and high temperature stages;

(6) according to the low-carbon pouring ladle slide plate brick, sodium tripolyphosphate and polyethylene glycol groups are used as a composite water reducing agent, and the electrostatic repulsion effect and the steric hindrance effect of ions in the water reducing agent after being dissolved in water are reasonably utilized, so that the fluidity of a pouring material is effectively improved, and the water adding amount is reduced;

(7) according to the low-carbon pouring ladle sliding plate brick, the mixture of the aluminum fibers and the polypropylene fibers is used as an explosion-proof agent, so that the drainage performance of the sliding plate brick in the pouring process, the primary curing process and the secondary curing process is effectively improved, the explosion-proof performance is improved, meanwhile, the high-temperature chemical performance of the sliding plate brick is effectively improved due to the addition of the aluminum fibers, and the service life of the sliding plate brick is prolonged;

(8) the low-carbon pouring ladle slide plate brick is added with a certain amount of high-temperature calcined bimodal active alpha-Al₂O₃Micro powder, nano and micro grade Al₂O₃The micro powder can optimize the grain size distribution of the casting material, increase the stacking density of the grains, and can also be used as a filling material to occupy fine gaps among the grains, so that the water consumption of the casting material is obviously reduced, and the fluidity and the bonding strength are improved; activated alpha-Al₂O₃The sintering densification of the sliding plate can be promoted at high temperature, and the high-temperature strength and the erosion resistance of the product are improved;

(9) the low-carbon pouring steel ladle sliding plate brick is prepared by adopting a multiple dispersion-pouring-multi-stage curing-asphalt dipping-dry distillation carbonization process, and the density of the sliding plate brick is improved by adopting a multiple dispersion process; the method adopts a dry distillation carbonization process after asphalt impregnation to form a graphite-shaped carbon mesh structure which is filled in the air holes of the sliding plate brick, and the graphite-shaped carbon mesh structure, the particle framework and the fine powder matrix form a mesh structure, so that the porosity, the volume density and the strength of the sliding plate brick are reduced, and meanwhile, the molten steel and steel slag corrosion resistance of the sliding plate brick is improved; the carbon source introduced by pitch impregnation and carbonization is uniformly distributed in the sliding plate brick, the residual content is low, the anti-corrosion effect is good, and the service life of the sliding plate brick is prolonged.

Drawings

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and examples, but it should be understood that these drawings are designed for illustrative purposes only and thus do not limit the scope of the present invention. Furthermore, unless otherwise indicated, the drawings are intended to be illustrative of the structural configurations described herein and are not necessarily drawn to scale.

FIG. 1 is a microscopic view of a slide plate brick of the present invention;

FIG. 2 is a photograph of a slide tile according to example 3 of the present invention before and after use;

FIG. 3 is a photograph of a slide tile of comparative example 1 of the present invention before and after use.

Detailed Description

The following detailed description of exemplary embodiments of the invention refers to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration exemplary embodiments in which the invention may be practiced. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that various changes to the invention may be made without departing from the spirit and scope of the present invention. The following more detailed description of the embodiments of the invention is not intended to limit the scope of the invention, as claimed, but is presented for purposes of illustration only and not limitation to describe the features and characteristics of the invention, to set forth the best mode of carrying out the invention, and to sufficiently enable one skilled in the art to practice the invention. Accordingly, the scope of the invention is to be limited only by the following claims.

The invention is further described with reference to specific examples.

Corundum particles having a particle diameter of 5 to 3mm, corundum particles having a particle diameter of 3 to 1mm, and a method for producing the same,Corundum particles of 1-0 mm, corundum fine powder of 0-0.045 mm, fused magnesia fine powder of 0-0.074 mm and nano Al₂O₃Fine powder of SiC and active alpha-Al₂O₃The micro powder, the composite binder, the water reducing agent and the explosion-proof agent are all raw materials purchased in the market.

The corundum particles and the corundum fine powder are one or more than one of sintered plate-shaped corundum, fused white corundum and fused brown corundum; al of sintered plate-like corundum and fused white corundum₂O₃The content is more than or equal to 99.3 percent, and the content R of the alkaline oxide₂O is less than or equal to 0.25 percent, R is K or Na, and the volume density is more than or equal to 3.55g/cm³(ii) a Al of fused brown corundum₂O₃The content is more than or equal to 95.8 percent, and TiO₂The content is less than or equal to 3 percent, SiO₂The content is less than or equal to 1.5 percent, and the volume density is more than or equal to 3.60g/cm³。

MgO content of fused magnesia fine powder is more than or equal to 98.2 percent, and SiO content₂The content is less than or equal to 0.9 percent, and the volume density is more than or equal to 3.50g/cm³；。

The active alpha-Al₂O₃The micro powder is high-temperature calcined bimodal Al₂O₃Micropowder, typical D50 bimodal 0.8 μm and 2.7 μm, Al₂O₃The content is more than or equal to 99 percent.

The composite binder is a composite of calcium aluminate cement, silicon micropowder and hydraulic alumina, wherein the mass ratio of the calcium aluminate cement to the silicon micropowder to the hydraulic alumina is (1-2): (4-5): (3-4).

The calcium aluminate cement is CA-80 cement, wherein Al is₂O₃The content is more than or equal to 76.5 percent, and the content of CaO is less than or equal to 22.5 percent; SiO in the silicon micro powder₂The content is more than or equal to 94.5 percent, and typical D50 is 0.15 mu m; the hydraulic alumina main crystal phase is rho-Al₂O₃，ρ-Al₂O₃The content is more than or equal to 99 percent.

The water reducing agent is a mixture of sodium tripolyphosphate and polyethylene glycol groups, and the mass percentage of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5.

the explosion-proof agent is a mixture of aluminum fibers and polypropylene fibers, and the mass percentage of the aluminum fibers to the polypropylene fibers is 7: 3.

the nano Al₂O₃Produced by gas phase processes, typicallyD50 ═ 13nm, BET specific surface area 100. + -. 15m²/g，Al₂O₃The content is more than or equal to 99.5 percent, and the pH value is 5-6.

The SiC fine powder is composed of black silicon carbide and green silicon carbide, and is of an alpha-SiC crystal form, wherein the mass content of the black silicon carbide is 70%, the mass content of the green silicon carbide is 30%, the SiC content in the black silicon carbide is more than or equal to 97%, the particle size is 0-0.074 mm, the SiC content in the green silicon carbide is more than or equal to 98%, and the particle size is 0-0.045 mm.

Nano Al₂O₃-SiC composite powder with nano Al₂O₃SiC fine powder as raw material, wherein the nano Al₂O₃The content of the composite powder is 20-40% by weight, and the balance is SiC fine powder.

Example 1

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 5% of plate-shaped corundum particles with the particle size of 5-3 mm, 35% of plate-shaped corundum particles with the particle size of 3-1 mm and 23% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 10% of fused white corundum fine powder with the particle size of 0-0.045 mm, 8% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 3%, active alpha-Al₂O₃10% of micro powder, 5% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 4: 6; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

the nano Al₂O₃The preparation method of the-SiC composite powder comprises the following steps: mixing nano Al₂O₃Weighing the SiC fine powder according to the proportion, and then putting the SiC fine powder into a HYB type high-speed airflow impact type mixer for mixing treatment, wherein the mixing treatment is carried out at low speed (the rotating speed of a host machine)100rpm) for 5min, then starting high-speed mixing (the running speed of the main machine is 800rpm) for 30min to ensure that the nano alumina particles are fully adsorbed and coated on the surface of the silicon carbide parent particles, further increasing the running speed of the main machine to 1300rpm for mixing for 3min, and grinding the silicon carbide particles with partial defects into spherical or near-spherical particles.

The preparation method of the low-carbon pouring ladle slide plate brick comprises the following steps:

(1) mixing fine powder: according to weight percentage, corundum fine powder with the grain diameter of 0-0.045 mm, fused magnesia fine powder with the grain diameter of 0-0.074 mm and nano Al₂O₃-SiC composite powder, active alpha-Al₂O₃Mixing the micro powder, the composite binder, the water reducing agent and the explosion-proof agent on an inclined high-speed mixer for 50min, wherein the rotating speed of a main machine of the mixer is 450 rpm;

(2) preparing granules: mixing plate-shaped corundum particles with the particle size of 5-3 mm, plate-shaped corundum particles with the particle size of 3-1 mm and fused white corundum particles with the particle size of 1-0 mm according to weight percentage;

(3) mixing the casting materials: putting the granules in the step (2) into a vertical shaft planetary stirrer for dry mixing for 5min, wherein the rotating speed of a main machine of the stirrer is more than or equal to 80rpm, adding the fine powder mixed in the step (1), continuously mixing and grinding for 6min, adding water accounting for 4 percent of the total weight, stirring for 10min, and discharging;

(4) pouring and vibration molding: pouring the mixed castable prepared in the step (3) into a mould twice, fixing the mould on a vibration platform through bolts, manually pouring the castable into the mould, then opening the vibration platform, primarily vibrating for 60 seconds, closing the vibration platform, then pouring the other half of the castable, vibrating for 6 minutes again, and stopping after floating slurry appears on the surface and no bubbles are generated;

(5) primary maintenance: curing the pouring semi-finished product prepared in the step (4) for 4 hours under a natural ventilation condition, then placing the pouring semi-finished product into a constant temperature room at 35-40 ℃ for 12 hours, and then placing the pouring semi-finished product into a constant temperature room at 60-70 ℃ for 12 hours;

(6) secondary curing: demolding the primarily cured product, gradually removing fastening screws of the steel template, taking down the poured sliding plate brick, placing the product in a medium-low temperature kiln for secondary curing, wherein the curing temperature is 280-300 ℃, and the curing time is 36 hours;

(7) asphalt impregnation: performing asphalt oil immersion treatment on the semi-finished product of the sliding plate brick subjected to low-temperature heat treatment in the step (6) in a vacuum oil immersion tank, wherein the asphalt softening point is 70-85 ℃, the temperature in the vacuum tank is 250 ℃, the oil immersion pressure maintaining time is 7 hours, and the pressure maintaining pressure is 2.2 MPa;

(8) dry distillation and carbonization: sealing the slide plate brick soaked by the asphalt in a gas kiln for dry distillation and carbonization treatment at 850 ℃ for 8 hours;

Example 2

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 8% of plate-shaped corundum particles with the particle size of 5-3 mm, 33% of plate-shaped corundum particles with the particle size of 3-1 mm and 20% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 14% of fused white corundum fine powder with the particle size of 0-0.045 mm, 6% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃4% of-SiC composite powder and active alpha-Al₂O₃6 percent of micro powder, 8 percent of composite bonding agent, 0.5 percent of water reducing agent and 0.5 percent of explosion-proof agent, and the total weight percentage is 100 percent; and liquid water accounting for 5 percent of the total weight is additionally added. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

the nano Al₂O₃The preparation method of the-SiC composite powder comprises the following steps: mixing nano Al₂O₃Mixing with SiC fine powder according to the proportionWeighing, placing into a HYB type high-speed airflow impact mixer for mixing treatment, firstly primarily mixing for 4min at a low speed (the rotating speed of a main machine is 150rpm), then starting high-speed mixing (the operating rotating speed of the main machine is 1000rpm) for mixing for 25min, enabling nano alumina particles to be fully adsorbed and coated on the surfaces of silicon carbide matrix particles, further increasing the operating rotating speed of the main machine to 1400rpm for mixing for 3min, and grinding silicon carbide particles with partial defects into spherical or near-spherical particles.

(1) mixing fine powder: according to weight percentage, corundum fine powder with the grain diameter of 0-0.045 mm, fused magnesia fine powder with the grain diameter of 0-0.074 mm and nano Al₂O₃-SiC composite powder, active alpha-Al₂O₃Mixing the micro powder, the composite binder, the water reducing agent and the explosion-proof agent on an inclined high-speed mixer for 40min, wherein the rotating speed of a main machine of the mixer is 450 rpm;

(3) mixing the casting materials: putting the granules in the step (2) into a vertical shaft planetary stirrer for dry mixing for 3min, wherein the rotating speed of a main machine of the stirrer is more than or equal to 80rpm, adding the fine powder mixed in the step (1), continuously mixing and grinding for 8min, adding water accounting for 5 percent of the total weight, stirring for 8min, and discharging;

(4) pouring and vibration molding: pouring the mixed castable prepared in the step (3) into a mould twice, fixing the mould on a vibration platform through bolts, manually pouring the castable into the mould, then opening the vibration platform, primarily vibrating for 60 seconds, closing the vibration platform, then pouring the other half of the castable, vibrating for 8 minutes again, and stopping after floating slurry appears on the surface and no bubbles are generated;

(5) primary maintenance: curing the pouring semi-finished product prepared in the step (4) for 3 hours under a natural ventilation condition, then placing the pouring semi-finished product into a constant temperature room at 35-40 ℃ for 10 hours, and then placing the pouring semi-finished product into a constant temperature room at 60-70 ℃ for 15 hours;

(6) secondary curing: demolding the primarily cured product, gradually removing fastening screws of the steel template, taking down the poured sliding plate brick, placing the product in a medium-low temperature kiln for secondary curing, wherein the curing temperature is 280-300 ℃, and the curing time is 24 hours;

(7) asphalt impregnation: performing asphalt oil immersion treatment on the semi-finished product of the sliding plate brick subjected to low-temperature heat treatment in the step (6) in a vacuum oil immersion tank, wherein the asphalt softening point is 70-85 ℃, the temperature in the vacuum tank is 230 ℃, the oil immersion pressure maintaining time is 7 hours, and the pressure maintaining pressure is 2.2 MPa;

(8) dry distillation and carbonization: sealing the slide plate brick after asphalt impregnation in a gas kiln for dry distillation and carbonization treatment at the temperature of 880 ℃ for 7 hours;

Example 3

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of plate-shaped corundum particles with the particle size of 5-3 mm, 28% of plate-shaped corundum particles with the particle size of 3-1 mm and 25% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of fused white corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

the nano Al₂O₃The preparation method of the-SiC composite powder comprises the following steps: mixing nano Al₂O₃Proportionally mixing with SiC fine powderAnd then putting the mixture into a HYB type high-speed airflow impact mixer for mixing, firstly primarily mixing for 3min at a low speed (the rotating speed of a main machine is 100rpm), then starting high-speed mixing (the operating rotating speed of the main machine is 1200rpm) for mixing for 30min, fully adsorbing and wrapping the nano alumina particles on the surfaces of the silicon carbide parent particles, further increasing the operating rotating speed of the main machine to 1500rpm for mixing for 3min, and grinding part of defective silicon carbide particles into spherical or near-spherical particles.

(1) mixing fine powder: according to weight percentage, corundum fine powder with the grain diameter of 0-0.045 mm, fused magnesia fine powder with the grain diameter of 0-0.074 mm and nano Al₂O₃-SiC composite powder, active alpha-Al₂O₃Mixing the micro powder, the composite binder, the water reducing agent and the explosion-proof agent on an inclined high-speed mixer for 60min, wherein the rotating speed of a main machine of the mixer is 450 rpm;

(3) mixing the casting materials: putting the granules in the step (2) into a vertical shaft planetary stirrer for dry mixing for 4min, wherein the rotating speed of a main machine of the stirrer is more than or equal to 80rpm, adding the fine powder mixed in the step (1), continuously mixing and grinding for 5min, adding water accounting for 4.5 percent of the total weight, stirring for 9min, and discharging;

(4) pouring and vibration molding: pouring the mixed castable prepared in the step (3) into a mould twice, fixing the mould on a vibration platform through bolts, manually pouring the castable into the mould, then opening the vibration platform, primarily vibrating for 60 seconds, closing the vibration platform, then pouring the other half of the castable, vibrating for 5 minutes again, and stopping when floating slurry appears on the surface and no bubbles are generated;

(5) primary maintenance: curing the pouring semi-finished product prepared in the step (4) for 3.5 hours under a natural ventilation condition, then placing the pouring semi-finished product into a constant temperature room at 35-40 ℃ for curing for 6 hours, and then placing the pouring semi-finished product into a constant temperature room at 60-70 ℃ for curing for 18 hours;

(6) secondary curing: demolding the primarily cured product, gradually removing fastening screws of the steel template, taking down the poured sliding plate brick, placing the product in a medium-low temperature kiln for secondary curing, wherein the curing temperature is 280-300 ℃, and the curing time is 30 hours;

(7) asphalt impregnation: performing asphalt oil immersion treatment on the semi-finished product of the sliding plate brick subjected to low-temperature heat treatment in the step (6) in a vacuum oil immersion tank, wherein the asphalt softening point is 70-85 ℃, the temperature in the vacuum tank is 200 ℃, the oil immersion pressure maintaining time is 8 hours, and the pressure maintaining pressure is 2.2 MPa;

(8) dry distillation and carbonization: sealing the slide plate brick soaked by the asphalt in a gas kiln for dry distillation and carbonization treatment at 900 ℃, and keeping the temperature for 6 hours;

Example 4

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of plate-shaped corundum particles with the particle size of 5-3 mm, 28% of plate-shaped corundum particles with the particle size of 3-1 mm and 25% of fused brown corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of fused brown corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 2: 5: 3; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

the nanometer scale of the present exampleAl₂O₃The preparation method of the-SiC composite powder was the same as in example 3.

The preparation method of the low-carbon pouring ladle slide plate brick of the embodiment is the same as that of the embodiment 3.

Example 5

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of plate-shaped corundum particles with the particle size of 5-3 mm, 28% of plate-shaped corundum particles with the particle size of 3-1 mm and 25% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of fused white corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 4: 6; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

nano Al described in this example₂O₃The preparation method of the-SiC composite powder was the same as in example 3.

Example 6

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of plate-shaped corundum particles with the particle size of 5-3 mm, 28% of plate-shaped corundum particles with the particle size of 3-1 mm and 25% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of fused white corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder5% body, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 3: 7; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Example 7

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of plate-shaped corundum particles with the particle size of 5-3 mm, 28% of plate-shaped corundum particles with the particle size of 3-1 mm and 25% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of fused white corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 2: 4: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

the example illustrates the Nano Al₂O₃The preparation method of the-SiC composite powder was the same as in example 3.

The preparation method of the low-carbon pouring ladle slide plate brick of the embodiment is the same as that of the embodiment 1.

Based on example 3, comparative example 1 and comparative example 2 are respectively the case of no addition of nano Al₂O₃-SiC composite powder, more than 5% of nano Al is added₂O₃-SiC composite powder, comparative Nano Al₂O₃The addition of the-SiC composite powder has influence on the service performance of the sliding brick.

Comparative example 1

The low-carbon pouring ladle slide plate brick of the comparative example is not added with nano Al₂O₃-SiC composite powder.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10 percent of plate-shaped corundum particles with the particle size of 5-3 mm, 28 percent of plate-shaped corundum particles with the particle size of 3-1 mm and 25 percent of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 14 percent of fused white corundum fine powder with the particle size of 0-0.045 mm, 6 percent of fused magnesia fine powder with the particle size of 0-0.074 mm, and active alpha-Al₂O₃10% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein the mass ratio of calcium aluminate cement, silica powder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Comparative example 2

The low-carbon pouring ladle slide plate brick of the comparative example is added with nano Al₂O₃The weight percentage of the-SiC composite powder is more than 5%.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the granuleThe granular materials comprise 10 percent of plate-shaped corundum particles with the particle size of 5-3 mm, 28 percent of plate-shaped corundum particles with the particle size of 3-1 mm and 25 percent of fused white corundum particles with the particle size of 1-0 mm, and the fine powder comprises 10 percent of fused white corundum fine powder with the particle size of 0-0.045 mm, 5 percent of fused magnesia fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 7%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃The mass percentage of the nano alumina to the SiC fine powder in the-SiC composite powder is 2: 8; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Data in Table 1 when example 3 is compared with comparative examples 1 and 2, it can be seen that nano Al is added in a proper amount₂O₃the-SiC composite powder can improve the density, the normal-temperature compressive strength, the high-temperature bending strength and the service life of the low-carbon pouring steel ladle slide plate brick.

Based on the example 3, the comparative example 3 and the comparative example 4 respectively do not add the fused magnesia fine powder, add more than 8% of the fused magnesia fine powder, and compare the influence of the addition of the fused magnesia fine powder on the use performance of the low-carbon pouring steel ladle slide plate brick.

Comparative example 3

The low-carbon pouring ladle slide plate brick of the comparative example does not contain fused magnesia fine powder.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the granular material comprises 10 percent of tabular corundum granules with the grain diameter of 5-3 mm28% of plate-shaped corundum particles with the particle size of 3-1 mm and 25% of electric melting white corundum particles with the particle size of 1-0 mm, wherein the fine powder comprises 17% of electric melting white corundum fine powder with the particle size of 0-0.045 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Comparative example 4

The low-carbon pouring ladle slide plate brick of the comparative example has the weight percentage of the fused magnesia fine powder over 8 percent.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of plate-shaped corundum particles with the particle size of 5-3 mm, 28% of plate-shaped corundum particles with the particle size of 3-1 mm and 25% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 7% of fused white corundum fine powder with the particle size of 0-0.045 mm, 10% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; calcium aluminate in composite binderThe mass ratio of the cement to the silicon micropowder to the hydraulic alumina is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Data in table 1, compared with comparative example 3 and comparative example 4, it can be seen that the compressive strength, erosion resistance, linear expansion performance and service life of the low-carbon cast ladle sliding plate brick can be improved by adding a proper amount of fused magnesia fine powder, and the analysis main reason is that a proper amount of corundum fine powder and fused magnesia fine powder react at high temperature to generate a certain amount of in-situ spinel, so that the open pores of the sliding plate brick can be effectively filled along with the volume increase effect, the porosity of the sliding plate brick is reduced, and the molten steel and steel slag erosion resistance is improved; however, excessive addition of fused magnesia causes a large volume expansion effect accompanied with the generation of spinel at high temperature, thereby causing fine cracks in the sliding plate and affecting the use effect.

Based on the example 3, the comparative examples 5, 6 and 7 are respectively the electric melting white corundum, the electric melting brown corundum and the sintering plate-shaped corundum which are independently used, and the influence of different types of corundum on the use performance of the low-carbon pouring steel ladle slide plate brick is contrasted and compounded.

Comparative example 5

The low-carbon pouring ladle slide plate brick of the comparative example is prepared by mixing corundum particles and corundum fine powder.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of fused white corundum particles with the particle size of 5-3 mm, 28% of fused white corundum particles with the particle size of 3-1 mm and 25% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of fused white corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesia fine powder with the particle size of 0-0.074 mm and nanometer Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃The mass percentage of the nano alumina to the SiC fine powder in the-SiC composite powder is 2: 8; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Comparative example 6

In the low-carbon pouring ladle slide plate brick of the comparative example, the corundum particles and the corundum fine powder are both fused brown corundum.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of fused brown corundum particles with the particle size of 5-3 mm, 28% of fused brown corundum particles with the particle size of 3-1 mm and 25% of fused brown corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of fused brown corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesia fine powder with the particle size of 0-0.074 mm, and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent is sodium tripolyphosphate and polyethylene glycol group, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groupIs 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Comparative example 7

In the low-carbon pouring ladle slide plate brick of the comparative example, the corundum particles and the corundum fine powder are both plate-shaped corundum.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of tabular corundum particles with the particle size of 5-3 mm, 28% of tabular corundum particles with the particle size of 3-1 mm and 25% of tabular corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of tabular corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesia fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Data in table 1, example 3 is compared with comparative examples 5, 6 and 7, and it can be seen that the high-temperature strength, high-temperature chemical stability, thermal shock stability and service life of the slide plate brick can be improved by compositely adding different types of corundum particles and corundum fine powder.

Based on example 3, comparative example 8, comparative example 9 and comparative example 10 are respectively the use of one of calcium aluminate cement, silica micropowder or hydraulic alumina as a binder, and the use performance of the low-carbon pouring ladle slide brick is influenced by using a composite binder.

Comparative example 8

The low-carbon pouring ladle slide plate brick of the comparative example uses the calcium aluminate cement as the bonding agent.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of plate-shaped corundum particles with the particle size of 5-3 mm, 28% of plate-shaped corundum particles with the particle size of 3-1 mm and 25% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of fused white corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8 percent of micro powder, 6 percent of calcium aluminate cement, 0.5 percent of water reducing agent and 0.5 percent of explosion-proof agent, and the total weight percentage is 100 percent; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Comparative example 9

The low-carbon pouring ladle slide plate brick of the comparative example uses silicon micropowder as the bonding agent.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the granuleThe granules comprise 10 percent of plate-shaped corundum particles with the particle size of 5-3 mm, 28 percent of plate-shaped corundum particles with the particle size of 3-1 mm and 25 percent of fused white corundum particles with the particle size of 1-0 mm, and the fine powder comprises 12 percent of fused white corundum fine powder with the particle size of 0-0.045 mm, 5 percent of fused magnesia fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8 percent of micro powder, 6 percent of silicon micro powder, 0.5 percent of water reducing agent and 0.5 percent of explosion-proof agent, and the total weight percentage is 100 percent; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Comparative example 10

The low-carbon pouring ladle slide plate brick of the comparative example is characterized in that the used binding agent is hydraulic aluminum oxide.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of plate-shaped corundum particles with the particle size of 5-3 mm, 28% of plate-shaped corundum particles with the particle size of 3-1 mm and 25% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of fused white corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8 percent of micro powder, 6 percent of hydraulic aluminum oxide, 0.5 percent of water reducing agent and 0.5 percent of explosion-proof agent, and the total weight percentage is 100 percent; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the water reducing agent is IIIThe sodium tripolyphosphate and the polyethylene glycol are mixed according to a mass ratio of 5: 5; the explosion-proof agent is aluminum fiber and polypropylene fiber, and the mass ratio of the aluminum fiber to the polypropylene fiber is 7: 3.

Table 1 data example 3 is compared with comparative examples 8, 9, and 10, and it can be seen that the apparent porosity of the sliding plate brick can be reduced, and the bulk density, high temperature strength, thermal shock resistance, and service life of the sliding plate brick can be improved by adding the composite binder, compared with adding only one additive.

Comparative example 11

Based on the example 3, the comparative example 11 is compared with the production process of multiple dispersion, pouring, multi-stage maintenance, asphalt impregnation, dry distillation and carbonization, which is adopted by the invention, without asphalt impregnation-dry distillation and carbonization, and has influence on the service performance of the low-carbon pouring steel ladle slide plate brick.

The low-carbon pouring ladle slide plate brick of the embodiment comprises the following components in percentage by weight: the particle material comprises 10% of plate-shaped corundum particles with the particle size of 5-3 mm, 28% of plate-shaped corundum particles with the particle size of 3-1 mm and 25% of fused white corundum particles with the particle size of 1-0 mm, and the fine powder material comprises 12% of fused white corundum fine powder with the particle size of 0-0.045 mm, 5% of fused magnesite fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder 5%, active alpha-Al₂O₃8% of micro powder, 6% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage is 100%; additionally adding liquid water accounting for 4.5 percent of the total weight. Wherein, the nano Al₂O₃Nano Al in-SiC composite powder₂O₃The mass percentage of the SiC fine powder is 2: 8; the mass ratio of calcium aluminate cement, silicon micropowder and hydraulic alumina in the composite binder is 1: 5: 4; the water reducing agent comprises sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5; the explosion-proof agent is aluminum fiber andthe aluminum fiber and the polypropylene fiber are in a mass ratio of 7: 3.

(1) mixing fine powder: according to weight percentage, corundum fine powder with the grain diameter of 0-0.045 mm, fused magnesia fine powder with the grain diameter of 0-0.074 mm and nano Al₂O₃-SiC composite powder, active alpha-Al₂O₃Micro powder and composite binder; mixing a water reducing agent and an explosion-proof agent on an inclined high-speed mixer for 50min, wherein the rotating speed of a main machine of the mixer is 450 rpm;

(2) preparing granules: white corundum particles with the particle size of 5-3 mm, white corundum particles with the particle size of 3-1 mm, aluminum magnesium spinel particles with the particle size of 3-1 mm and aluminum magnesium spinel particles with the particle size of 1-0 mm are mixed according to weight percentage;

(3) mixing the casting materials: putting the granules in the step (2) into a vertical shaft planetary stirrer for dry mixing for 5min, wherein the rotating speed of a main machine of the stirrer is more than or equal to 80rpm, adding the fine powder mixed in the step (1), continuously mixing and grinding for 8min, adding water accounting for 4-5% of the total weight, stirring for 10min, and discharging;

(6) secondary curing: demoulding the product of the primary curing, gradually removing the fastening screws of the steel template, taking down the pouring slide plate brick, placing the product in a medium-low temperature kiln for secondary curing at the curing temperature of 200 ℃ and 300 ℃ for 36 hours;

(7) finishing treatment: and (4) performing steel hoop polishing, double-sided grinding, non-working surface veneering, drying and sliding surface coating treatment on the semi-finished sliding plate brick obtained after curing in the step (6), and packaging after inspection to obtain the finished sliding plate brick.

Data in table 1 as compared with comparative example 11, it can be seen that the slide plate brick produced by the multiple dispersion-casting-multi-stage curing-asphalt impregnation-dry distillation carbonization process has lower apparent porosity, better compressive strength, thermal shock stability and longer service life.

TABLE 1 physicochemical Properties of Low-carbon-poured ladle slide brick described in examples 1 to 7 and comparative examples 1 to 11

The above description is a more detailed description of the present invention with reference to specific preferred embodiments, and it is not intended to limit the present invention to the specific embodiments described above. It will be apparent to those skilled in the art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the invention.

Claims

1. Nano Al₂O₃-SiC composite powder, wherein the Al is₂O₃Uniformly dispersed on the surface of SiC fine powder, Al₂O₃D50 ═ 13 nm.

2. The nano Al of claim 1₂O₃-SiC composite powder, wherein the Al is₂O₃The weight ratio of the SiC fine powder to the SiC fine powder is (20-40%): (60% to 80%) of the above Al₂O₃The sum of the weight proportion of the SiC fine powder and the weight proportion of the SiC fine powder is 100 percent; the Al is₂O₃The pH value of the SiC fine powder is 5-6, and the SiC fine powder is a mixture of black silicon carbide and green silicon carbide.

3. A method for preparing the nano Al of claim 1₂O₃-SiC composite powder, characterized in that the nano Al₂O₃the-SiC composite powder is produced by adopting a gas phase method, and the method comprises the following steps:

(2) mixing materials: impinging the Al with a high velocity gas stream₂O₃Mixing with SiC fine powder.

4. The nano Al of claim 3₂O₃The preparation method of the-SiC composite powder is characterized in that Al in the step (2)₂O₃Mixing the SiC fine powder and the high-speed airflow impact type mixer for 3-5 min, wherein the rotating speed of a main machine is 100-200 rpm; mixing materials at a high speed for 20-30 min, wherein the rotating speed of a main machine is 800-1200 rpm; further mixing the materials for 3min, wherein the rotating speed of the main machine is more than or equal to 1200 rpm.

5. The low-carbon pouring steel ladle sliding plate brick comprises a granular material and fine powder, and is characterized in that the granular material comprises 5-10% of corundum particles with the particle size of 5-3 mm, 28-35% of corundum particles with the particle size of 3-1 mm and 20-25% of corundum particles with the particle size of 1-0 mm in percentage by mass; the fine powder comprises 10-16% of corundum fine powder with the particle size of 0-0.045 mm, 5-8% of fused magnesia fine powder with the particle size of 0-0.074 mm, and nano Al in percentage by mass₂O₃3 to 5 percent of-SiC composite powder and active alpha-Al₂O₃6-10% of micro powder, 5-8% of composite binder, 0.5% of water reducing agent and 0.5% of explosion-proof agent, wherein the total weight percentage of the granular material and the fine powder material is 100%; water accounting for 4 to 5 percent of the total weight is added.

6. The low-carbon pouring ladle slide plate brick according to claim 5, wherein the composite binder is a composite of calcium aluminate cement, silicon micropowder and hydraulic alumina, and the mass ratio of the calcium aluminate cement to the silicon micropowder to the hydraulic alumina is (1-2): (4-5): (3-4).

7. The low-carbon pouring steel ladle slide plate brick as claimed in claim 5, wherein the water reducing agent is a mixture of sodium tripolyphosphate and polyethylene glycol groups, and the mass ratio of the sodium tripolyphosphate to the polyethylene glycol groups is 5: 5.

8. the low-carbon pouring ladle slide plate brick as claimed in claim 5, wherein the explosion-proof agent is a mixture of aluminum fibers and polypropylene fibers, and the mass ratio of the aluminum fibers to the polypropylene fibers is 7: 3.

9. a method of making the low carbon poured ladle slide plate brick of claims 5-8, comprising the steps of:

(1) mixing fine powder: proportionally mixing corundum fine powder with the particle size of 0-0.045 mm, fused magnesia fine powder with the particle size of 0-0.074 mm and nano Al₂O₃-SiC composite powder, active alpha-Al₂O₃Mixing the micro powder, the composite binder, the water reducing agent and the explosion-proof agent;

(3) mixing the casting materials: mixing and stirring the granular materials in the step (2), adding the fine powder mixed in the step (1), continuously mixing and grinding, adding water in proportion, stirring and discharging;

(4) pouring and vibration molding: pouring the casting material prepared in the step (3) into a mould twice, and stopping when floating slurry appears on the surface and no bubbles are generated;

(5) primary maintenance: curing the pouring semi-finished product prepared in the step (4) under a natural ventilation condition;

(6) secondary curing: demolding the primarily cured product, and placing the product in a medium-low temperature kiln for secondary curing;

(7) asphalt impregnation: performing oil immersion treatment on the semi-finished product of the sliding plate brick subjected to secondary maintenance in the step (6);

(8) dry distillation and carbonization: sealing the slide plate brick after asphalt impregnation in a gas kiln for dry distillation and carbonization treatment;

10. The preparation method of the low-carbon pouring ladle slide plate brick according to claim 9, wherein the fine powder in the step (1) is mixed for 40-60 min; mixing the granules in the step (3) for 3-5 min, mixing and grinding the fine powder for 5-8 min, adding water and stirring for 8-10 min; the mixed castable is subjected to initial shock for 60 seconds, the vibration platform is closed, the other half of the castable is poured in, and the vibration is carried out for 5-8 min again; curing for 3-4 hours in the step (5), and curing for 6-12 hours at the constant temperature of 35-40 ℃ and curing for 12-18 hours at the constant temperature of 60-70 ℃; in the step (6), the secondary curing temperature is 280-300 ℃, and the curing time is 24-36 hours; the softening point of the asphalt in the step (7) is 70-85 ℃, the oil immersion temperature is 200-250 ℃, the oil immersion pressure maintaining time is more than 6 hours, and the pressure maintaining pressure is more than 2 MPa; and (8) performing dry distillation and carbonization treatment at 850-900 ℃ for 6-8 hours.