High strength ceramic wear-resistant castable

Abstract

The invention discloses a high-strength ceramic wear-resistant castable, which includes sintered mullite, brown corundum, white corundum, premixed powder, bimodal activated alumina powder, 92 silicon powder, 71 pure calcium aluminate cement, kyanite, sodium hexametaphosphate, sodium tripolyphosphate, and EV explosion-proof fiber; wherein the premixed powder is obtained by ball milling SiSiCar, alumina powder, and boron carbide powder. The castable uses SiSiCar, a cutting waste material in the solar energy industry, to prepare the wear-resistant castable, which has the characteristics of low cost, high strength, good wear resistance, excellent thermal shock resistance, etc., while achieving energy conservation and emission reduction, and reducing the overall cost of the wear-resistant castable.

Description

Technical Field

[0001] The invention relates to the technical field of refractory materials, in particular to a high-strength ceramic wear-resistant castable. Background Art

[0002] Metallurgical equipment needs to use various types of wear-resistant castables according to the characteristics of its working environment. Taking the hot blast furnace as an example, the hot blast furnace matched with the blast furnace is basically built by firing shaped products, such as the air supply main pipe, branch pipe, surrounding pipe and pipe joints connected to the blast furnace. Some parts with complex shapes need to be completed with thermal shock resistant and highly wear-resistant castables. Including local damage and brick falling during operation, wear-resistant castables are also needed for hot repair to avoid the huge economic losses caused by the shutdown of the furnace due to the masonry method.

[0003] Generally speaking, under the same conditions, wear resistance is positively correlated with hardness, that is, positively correlated with density, and negatively correlated with surface roughness. Therefore, the harder the wear-resistant material, the more wear-resistant it is. For example, cast iron has a low hardness, and cast iron is often used in the camshaft of the engine. More typically, the wear-resistant layer of the sliding bearing uses babbitt alloy, which has a low hardness. In addition, in order to enhance the wear resistance of the worm gear reducer, a bronze alloy with low hardness is generally used as the worm gear. Wear resistance requires embeddability and friction compliance, that is, the material can quickly form a friction surface with concave and convex matching the two friction surfaces after grinding. If the surface hardness is simply pursued, the hard material is not easy to run-in, but will reduce the wear resistance of the friction surface. Refractory materials are inorganic non-metallic materials, and they have the remarkable characteristic of brittleness. Therefore, inorganic non-metallic material workers have been exploring, hoping to achieve materials with both hardness and toughness. Under the same material conditions, thermal shock stability is often negatively correlated with the density of the material. A large number of literature and application practices show that cross-combination of basic raw materials such as high aluminum series (including corundum), mullite series and silicon carbide series is suitable for preparing wear-resistant castables with high strength, good wear resistance and excellent thermal shock resistance. At present, the overall cost of wear-resistant castables is generally high due to the use of high-quality directional raw materials, and the price remains high for a long time, which directly affects the cost control of wear-resistant castable applications. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a high-strength ceramic wear-resistant castable, in which SiSiCar, the cutting waste of the solar energy industry, is used to prepare the wear-resistant castable, which has the characteristics of low cost, high strength, good wear resistance, excellent thermal shock resistance, etc., while achieving energy conservation and emission reduction and reducing the overall cost of the wear-resistant castable.

[0005] In order to solve the above technical problems, the high-strength ceramic wear-resistant castable of the present invention comprises 20-35wt% sintered mullite with a particle size of 5-3mm, 8-22wt% sintered mullite with a particle size of 3-1mm; 6-14wt% sintered mullite with a raw material particle size of 1-0mm, 8-16wt% brown corundum, 10-18wt% white corundum with a particle size of 180 mesh, 8-16wt% white corundum with a particle size of 325 mesh, 6-12wt% premixed powder, and bimodal active 5-10wt% alumina micropowder, 2-7wt% 92% silicon micropowder, 2-9wt% 71% pure calcium aluminate cement, 5-8wt% kyanite, 0.05-0.2wt% sodium hexametaphosphate, 0.05-0.2wt% sodium tripolyphosphate, 0.01-0.05wt% EV explosion-proof fiber; wherein, the premixed powder is obtained by ball milling at 200 rpm for 5 hours with 5 parts of SiSiCar waste, 4.8 parts of alumina micropowder and 0.2 parts of boron carbide powder.

[0006] Furthermore, the particle size of the SiSiCar waste in the premixed powder is 200-2000 meshes, the particle size of the alumina powder is 500-800 meshes, and the particle size of the boron carbide powder is 200 meshes.

[0007] Furthermore, the particle size of the brown corundum is 1-0 mm, the particle size of the bimodal activated alumina powder is 1 micron, and the particle size of the kyanite is 40-80 mesh.

[0008] Since the high-strength ceramic wear-resistant castable of the present invention adopts the above technical solution, that is, the castable includes sintered mullite, brown corundum, white corundum, premixed powder, bimodal activated alumina powder, 92 silicon powder, 71 pure calcium aluminate cement, kyanite, sodium hexametaphosphate, sodium tripolyphosphate, and EV explosion-proof fiber; wherein the premixed powder is obtained by ball milling SiSiCar, alumina powder, and boron carbide powder. The castable uses SiSiCar, the cutting waste of the solar energy industry, to prepare wear-resistant castables, which has the characteristics of low cost, high strength, good wear resistance, excellent thermal shock resistance, etc., while achieving energy conservation and emission reduction, and reducing the overall cost of wear-resistant castables. DETAILED DESCRIPTION

[0009] The high-strength ceramic wear-resistant castable comprises 20-35wt% sintered mullite with a particle size of 5-3mm, 8-22wt% sintered mullite with a particle size of 3-1mm, 6-14wt% sintered mullite with a particle size of 1-0mm, 8-16wt% brown corundum, 10-18wt% white corundum with a particle size of 180 mesh, 8-16wt% white corundum with a particle size of 325 mesh, 6-12wt% premixed powder, and bimodal activated alumina micropowder. 5-10wt%, 92 silicon powder 2-7wt%, 71 pure calcium aluminate cement 2-9wt%, kyanite 5-8wt%, sodium hexametaphosphate 0.05-0.2wt%, sodium tripolyphosphate 0.05-0.2wt%, EV explosion-proof fiber 0.01-0.05wt%; among which, the premixed powder is obtained by ball milling at 200 rpm for 5 hours using 5 parts of SiSiCar waste, 4.8 parts of alumina powder, and 0.2 parts of boron carbide powder. Kyanite can also be replaced by andalusite, or a mixture of kyanite and andalusite.

[0010] SiSiCar is the trade name for solid waste recovered from the production of polysilicon wafers or by-products processed during the polysilicon processing process.

[0011] According to the use environment and life cost requirements, the aggregates in this castable can be replaced by corundum, alumina, mullite and the like with high hardness.

[0012] Preferably, the particle size of the SiSiCar waste in the premixed powder is 200-2000 mesh, the particle size of the alumina powder is 500-800 mesh, and the particle size of the boron carbide powder is 200 mesh.

[0013] Preferably, the particle size of the brown corundum is 1-0 mm, the particle size of the bimodal activated alumina powder is 1 micron, and the particle size of the kyanite is 40-80 mesh. Based on the above formula, the type and proportion of aggregates can be changed according to different usage scenarios, and those skilled in the art can adjust them by themselves.

[0014] Aggregates such as corundum, alumina, and mullite in this castable are wear-resistant materials themselves. SiSiCar is a mixture containing silicon carbide, elemental silicon, and elemental iron. Boron carbide is added to the premixed powder, which has a lubricating effect itself and can also protect elemental silicon and elemental iron from oxidation at high temperatures. Elemental iron and elemental silicon also have a lubricating and ductile effect, which improves the toughness of this castable in the entire temperature range. The aggregates and excellent bonding system of this castable fully guarantee the high strength and high wear resistance of the castable, which can be verified from the strength shown at various temperatures.

[0015] This castable fully considers the hardness and thermal shock resistance of each material, and selects wear-resistant materials such as corundum series, alumina series, silicon carbide series and materials with excellent thermal shock resistance such as mullite series as the main raw materials, and assists the matrix powder to form particles as round as possible through ball milling to increase the surface finish, thereby improving the wear resistance. At the same time, boron carbide and EV explosion-proof fiber are added to increase the anti-burst performance and thermal shock stability. Among them, boron carbide generates carbon dioxide after oxidation, and small pores are formed inside the material, or small channels are formed after gas escape and fiber combustion, which can play a role in micro-crack toughening, thereby achieving the effect of improving thermal shock.

[0016] This castable uses SiSiCar, the cutting waste of the solar industry, to prepare wear-resistant castables, turning waste into treasure and reducing direct costs by about 15%. When silicon is used at medium and high temperatures, it begins to show ductility or toughness at 700-800°C. Moreover, according to the oxygen potential diagram, at higher temperatures above 1100°C, silicon is oxidized preferentially over silicon carbide, forming dense and smooth SiO2 on the surface, which protects silicon carbide. All these improve the wear resistance and thermal shock stability of this wear-resistant castable.

Claims

1. A high-strength ceramic wear-resistant castable, characterized in that: It includes 20-35wt% sintered mullite with a particle size of 5-3mm, 8-22wt% sintered mullite with a particle size of 3-1mm, 6-14wt% sintered mullite with a particle size of 1-0mm, 8-16wt% brown corundum, 10-18wt% white corundum with a particle size of 180 mesh, 8-16wt% white corundum with a particle size of 325 mesh, 6-12wt% premixed powder, 5-10wt% bimodal activated alumina powder, 2-7wt% 92 silicon powder, 2-9wt% 71 pure calcium aluminate cement, 5-8wt% kyanite, 0.05-0.2wt% sodium hexametaphosphate, 0.05-0.2wt% sodium tripolyphosphate, and 0.01-0.05wt% EV explosion-proof fiber; wherein the premixed powder is obtained by ball milling 5 parts of SiSiCar waste, 4.8 parts of alumina powder, and 0.2 parts of boron carbide powder at 200 rpm for 5 hours.

2. The high-strength ceramic wear-resistant castable according to claim 1, characterized in that: The particle size of SiSiCar waste in the premixed powder is 200-2000 meshes, the particle size of alumina micropowder is 500-800 meshes, and the particle size of boron carbide powder is 200 meshes.

3. The high-strength ceramic wear-resistant castable according to claim 1 or 2, characterized in that: The particle size of the brown corundum is 1-0 mm, the particle size of the bimodal activated alumina powder is 1 micron, and the particle size of the kyanite is 40-80 meshes.