Light-weight corundum-magnesium aluminate spinel castable and preparation method thereof

Abstract

The invention relates to a light-weight corundum-magnesium aluminate spinel castable and a preparation method thereof. The technical scheme of the invention is taking nano-aperture porous corundum-magnesium aluminate spinel ceramic particles with the partical sizes successively being 3-5mm, 1-2.5mm and 0.1-0.5mm as aggregates, taking nano-aperture porous corundum-magnesium aluminate spinel ceramic fine powder with the partical size being smaller than 0.074mm, magnesium aluminate spinel fine powder, corundum fine powder, magnesia fine powder and alpha-Al2O3 micro powder as matrixes and taking aluminate cement as a binding agent; the preparation method comprises the following steps: mixing the matrixes, the binding agent and sodium hexametaphosphate firstly, then adding the aggregates, uniformly mixing, then adding water, uniformly stirring, moulding by casting, carrying out maintenance, demoulding and drying, and keeping the temperature for 2-6h at the condition with the temperature being 1450-1600 DEG C to obtain the light-weight corundum-magnesium aluminate spinel castable. By adopting the light-weight corundum-magnesium aluminate spinel castable and the preparation method, the process is simple, and a prepared product has the average pore size in a nanoscale, is low in heat conductivity coefficient, good in medium erosion and penetrability resistance and high in thermal shock resistance, and is suitable for parts, including bottoms, walls and the like, of steel ladles.

Description

technical field [0001] The invention belongs to the technical field of corundum-magnesium aluminum spinel castables. In particular, it relates to a lightweight corundum-magnesium aluminum spinel castable and a preparation method thereof. Background technique [0002] The corundum-magnesium aluminum spinel castable has the advantages of convenient construction, strong high-temperature mechanical properties and good slag resistance, and is widely used in ladle bottoms and cladding walls. However, there are some problems in corundum-magnesium aluminum spinel castables at present: (1) The thermal conductivity is high. Since the existing corundum-spinel castables are made of dense corundum aggregates, the thermal conductivity is relatively large, and the heat dissipation through the cladding wall is relatively small. (2) The thermal shock stability is poor. During the working process of the ladle, the drastic temperature change causes the corundum-spinel castable to bear huge th...

AI Technical Summary

Problems solved by technology

However, there are some problems in corundum-magnesium aluminum spinel castables at present: (1) The thermal conductivity is high. Since the existing corundum-spinel castables are made of dense corundum aggregates, the thermal conductivity is relatively large, and the heat dissipation through the cladding wall is relatively small. (2) The thermal shock stability is poor. During the working process of the ladle, the drastic temperature change causes the corundum-spinel castable to bear huge thermal stress, destroys the material structure, and produces Peeling damage; (3) Uneven composition distribution. In corundum-magnesium aluminum spinel castables, spinel is generally distributed in the matrix, resulting in uneven distribution of spinel in the material, which is easy to be caused by corundum and spinel Different thermal expansion coefficients cause internal stress

Another example is the patented technology of "a lightweight aluminum-magnesium castable and its preparation method" (CN201410467630.X), which uses microporous corundum-spinel particles as aggregates to prepare lightweight aluminum-magnesium castables, but the aggregate is fired The temperature is as high as 1750 ~ 1900 ℃, and the energy consumption is large

"A light-weight corundum-spinel castable and its preparation method" (CN201510550636.8) patent technology, although the lightweight corundum-spinel castable is also prepared with equal-diameter microporous corundum balls as aggregates, but there are The following disadvantages: only corundum phase in the aggregate, resulting in uneven distribution of magnesia-aluminum spinel in the castable, and cracks are likely to occur inside the material at high temperature; spherical aggregate will cause the interface between the aggregate and the matrix in the material to be larger than that of the existing material Small, reducing the bonding strength of the aggregate and the matrix; the firing temperature of the aggregate is as high as 1900-2100°C, and the energy consumption is high