A kind of aluminum oxide hollow sphere thermal insulation product

Abstract

The invention belongs to the technical field of refractory materials, and provides an alumina hollow ball insulation product. One or more than two of low-cost waste corundum bricks, waste corundum-mullite bricks, waste alumina hollow ball bricks and waste corundum ceramic products are used as raw materials to completely or partially substitute an industrial Al2O3 raw material, the alumina hollow balls are prepared through smelting and blowing of a three-phase arc furnace as aggregate, one or more than two of the low-cost waste corundum bricks, the waste corundum-mullite bricks, the waste alumina hollow ball bricks and the waste corundum ceramic products are crushed to form fine powder, sintered Al2O3 fine powder or electrically-molten Al2O3 fine powder is completely or partially replaced by the fine powder to be as a base raw material, and the alumina hollow ball insulation product can be obtained through shaping, drying and sintering. The alumina hollow ball insulation product has the advantages of low cost, good thermal insulating effect, high strength and stable performance, and can be used in an intermediate / high-temperature environment of rapid temperature change for a long term. The raw materials are abundant in source, easy to recycle and low-cost; and the purpose of resource reutilization can be achieved.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, and in particular relates to a hollow aluminum oxide sphere which can be used for a long time in a medium-high temperature kiln below 1700°C and has low manufacturing cost, good heat insulation effect and stable high-temperature performance. products. Background technique [0002] Alumina hollow sphere heat insulation products have good fire resistance, high strength and excellent heat insulation performance. They are often used as working linings for medium-high temperature and ultra-high temperature thermal kilns as insulation materials, which can reduce heat loss and speed up heating. Thereby reducing energy consumption and saving production costs. [0003] The preparation methods of alumina hollow sphere heat insulation products used in the field of medium and high temperature kilns usually include the following two types: one is self-bonded alumina hollow sphere heat insulation...

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Problems solved by technology

[0003] The preparation methods of alumina hollow sphere heat insulation products used in the field of medium and high temperature kilns usually include the following two types: one is self-bonded alumina hollow sphere heat insulation products, and the aggregate is made of industrial Al 2 o 3 As a raw material, it is melted and blown into a high-purity hollow sphere in a three-phase electric arc furnace, and the matrix is ​​sintered Al 2 o 3 powder, fused Al 2 o 3 powder or sintered Al 2 o 3 with fused Al 2 o 3 The mixed powder is used as the raw material, and the high-purity product is fired at high temperature or ultra-high temperature, and the Al in the product 2 o 3 The total content of the product reaches more than 98%; the advantage of this product is that the use temperature is high, and the maximum use temperature can reach above 1800 ℃; the disadvantage is the high cost of raw materials, difficult sintering, poor thermal shock stability, etc.; the other is mullite combined Alumina hollow sphere thermal insulation products, the aggregate is industrial Al 2 o 3 As a raw material, it is melted and blown into a high-purity hollow sphere in a three-phase electric arc furnace, and the matrix is ​​sintered Al 2 o 3 powder or fused Al 2 o 3 SiO 2 The mixed powder of clay, andalusite, sillimanite or mullite is used as raw material and fired at high temperature. Al in the product 2 o 3 The total content is about 90%; the advantages of this product are high strength and good thermal shock resistance; the disadvantage is that the different types of aggregate and matrix raw materials, as well as the different grades of different matrix raw materials, make it difficult to control the production process and easily lead to burning. Decrease in the finished product yield, resulting in an increase in production costs

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