Composite reinforced porous spinel-corundum-carbon ceramic filter and preparation method thereof

Abstract

The invention relates to a composite reinforced porous spinel-corundum-carbon ceramic filter and a preparation method thereof. The technical solution is: 81-90wt% modified porous spinel-corundum ceramic powder, 3-6wt% modified coal tar pitch powder, 0.6-3wt% elemental silicon powder and 5-10wt% corundum Micropowder is the raw material, and the raw material is stirred with a water reducing agent accounting for 0.3-1.5wt% of the raw material to obtain a mixture; then a rheological agent accounting for 0.6-3wt% of the raw material, 3.5-7wt% of silica sol, 0.1-0.35wt% The antifoaming agent and 25-42wt% deionized water are stirred to obtain a mixed solution; the mixture and the mixed solution are stirred to obtain a slurry; the silicon carbide preform is completely immersed in the slurry, centrifuged, dried, and buried Carbon conditions and heat preservation at 1330-1480 ° C, cooling, to prepare a composite reinforced porous spinel-corundum-carbon ceramic filter. The product produced by the invention has excellent mechanical properties, good thermal shock stability, long service life and excellent filtering effect.

Description

technical field [0001] The invention belongs to the technical field of porous spinel-corundum-carbon ceramic filter. In particular, it relates to a composite reinforced porous spinel-corundum-carbon ceramic filter and a preparation method thereof. Background technique [0002] Inclusions in molten steel are an important factor affecting steel quality, and removing inclusions and improving the purity of molten steel are important ways to improve steel quality. In the final link of molten steel pouring, introducing porous ceramic filters to filter out inclusions in molten steel is an important method to effectively purify molten steel and improve steel quality. [0003] At present, there have been reports on ceramic filters used for filtering molten steel. For example, the patented technology of "zirconia foam ceramic filter" (CN101164657A) uses zirconia, alumina, calcium oxide and yttrium oxide as raw materials, and uses soft polyurethane foam as a carrier to prepare a zirc...

AI Technical Summary

Problems solved by technology

For example, the patented technology of "zirconia foam ceramic filter" (CN101164657A) uses zirconia, alumina, calcium oxide and yttrium oxide as raw materials, and uses soft polyurethane foam as a carrier to prepare a zirconia foam ceramic However, due to the strong chemical stability of zirconia at high temperature, the chemical adsorption capacity for inclusions is weak, the filtering effect is limited, and the stabilizer is easily lost when zirconia contacts with slag, and the product will be damaged due to the volume change caused by the crystal transformation. damaged

Another example is the "preparation method of alumina porous ceramic foam filter" (CN103848642A) patent technology, using industrial alumina etc. The raw material used in the technology is dense powder, and the resulting product has a hollow structure and a dense surface, which has a weak interaction with the inclusions in the molten steel, and it is difficult to absorb small-sized inclusions in the molten steel, and the product has low strength, poor thermal shock stability, and low service life.

Another example is the "silicon carbide foam ceramic filter" (CN101165655A) patent technology, which uses silicon carbide, alumina, silicon dioxide and talc as raw materials, and uses soft polyurethane foam as a carrier to prepare a silicon carbide foam Ceramic filter, but silicon carbide is a non-oxide, which has poor affinity and weak interaction with oxide inclusions in molten steel, resulting in limited adsorption capacity of the product for oxide inclusions and poor filtering effect

Another example is the literature technology (Ding Junjie, et al. The influence of the secondary coating process on the properties of SiC-based foam ceramics for casting. Refractories, 2020.54(2):137-140), using SiC micropowder, α-Al 2 o 3 Micropowder and silica sol are used as raw materials, organic foam is used as a template, and SiC-based foam ceramics are prepared by double-hanging the pre-fired green body, but the surface of the pre-fired green body shows large cracks and the green body has low strength. , the resulting product has low skeleton strength and short service life

[0004] To sum up, there are still several problems in the existing porous ceramic filter technology for molten steel. First, the surface of the filter skeleton is dense, the adsorption capacity for inclusions is limited, and the filtering effect is poor; second, the strength of the filter skeleton is low. , poor thermal shock stability, short service life