Sillimanite brick for large-scale blast furnace hot blast stove and method of manufacturing the same

Abstract

The invention discloses a sillimanite brick used in the large blast furnace stove and a production method thereof. The raw material of the sillimanite brick contains 30 to 60 percent of mullite, 30 to 60 percent of sillimanite or / and andalusite and 10 to 40 percent of common milling powder, and additionally, a binder, whose weight accounts for 2 to 5 percent of the total weight of the above raw materials, is added into the above raw materials. The production method of the brick comprises mulling, aging, molding, drying and firing processes; and green bricks are heat preserved for 8 to 12 hours under 1480 to 1520 DEG C to be fired, and are taken out of the kiln after being cooled naturally. The creep rate of the sillimanite brick is only 0.179 percent in the conditions of 1450 DEG C and 50 hours, the compressive strength reaches 76.2 Mpa, and the service life of the product is long. Thus, the product can completely meet the performance requirements of the sillimanite brick used in the blast furnace stove, and the product surpasses the performances of the same kind products at home and abroad and ends the history that the product has been imported from foreign countries all the time.

Description

1. Technical field: [0001] The invention relates to the field of refractory materials, in particular to a sillimanite brick for a large blast furnace hot blast stove and a production method thereof. 2. Background technology: [0002] At present, the main forms of refractory materials for domestic hot blast stoves are: (1) silica brick - high alumina brick - clay brick; (2) low creep high alumina brick (mullite brick) - high alumina brick - clay brick; ( 3) Silica brick - low creep brick - high alumina brick - clay brick. No matter which form is used, the material of the high temperature part is the key to the material selection of the hot blast stove. Taken together, there are two types of key materials: silica bricks and low creep bricks. When the hot blast temperature is 1100-1200°C, high alumina bricks, mullite bricks and silica bricks are generally used as furnace lining or checker bricks; when the hot blast temperature is higher than 1200°C, high alumina bricks cannot...

AI Technical Summary

Problems solved by technology

However, silica bricks also have disadvantages: poor volume stability at low temperatures, and large volume changes will occur between 0 and 600 °C; poor thermal shock resistance at low temperatures, and easy to crack; silica bricks have low density and small heat capacity. When used as checker bricks, its heat storage is not large

Among them, the andalusite refractory material has been well promoted in hot blast stoves, but at present, most manufacturers at home and abroad mostly add a small amount of andalusite to the material, using high-alumina bauxite as the main raw material, which makes the performance of the product decline and cannot be refractory. Meet the requirements of long life of hot blast furnace

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