How High Alumina Refractory Bricks Are Made

How High Alumina Refractory Bricks Are Made

High alumina refractory bricks are commonly used to line furnaces and other refractory applications. These bricks are characterized by high temperature performance, great corrosion and wear resistance, and high bulk density. They are also resistant to acid and alkali slag erosion. They are a very popular type of refractory material and are manufactured in various ways depending on their application.

Traditionally, refractory bricks are made of clay or other lower alumina silicates such as corundum. These materials are a good choice for refractory applications, however, they do not have the same strength or durability as higher alumina silicates. This is why there are several different types of refractory bricks available.

The most common way to manufacture high alumina brick is through the use of bauxite. This refractory material is calcined and then formed into bricks. Once fired it creates a mixture of aluminum oxide and something called "kaolinitic clay". This mix is what makes high alumina brick so durable and strong.

Other ways to produce a high alumina refractory brick include using mullite or other ceramic materials. These materials can be more expensive than alumina, but they do have the added benefit of being highly heat resistant and durable.

Another method of producing a high alumina refractory block is through the use of a solid foam. This type of brick can be more economical than traditional clay bricks because they are cheaper to make.

In this study, the thermal conductivity of alumina foams of different bulk density p was investigated. The results showed that alumina foams of p less than 0.1 g/cm3 had a thermal conductivity of 0.12 W/mK at room temperature. This was slightly lower than the thermal conductivity of alumina itself, which decreased with increasing temperature.

Additionally, the compressive and tensile properties of high alumina refractory bricks made of foam were evaluated. The results showed that the compressive and tensile strengths of the bricks increased by 50-100% at around 1000 degC.

The results also showed that the refractoriness of high alumina bricks was not lower than 1750-1790C, making them a good option for lining blast furnaces and hot blast stoves. This is due to their high alumina content and the fact that they are able to resist both acid and alkali slag erosion.

X-ray diffraction patterns of the refractory bricks revealed that they were composed of 43% alumina, 22% mullite, 12% leucite and 2% sillimanite. The mullite and leucite were present as grains, while the sillimanite was a single crystal. The alumina was found to be dominated by the oxide layer, with some silica and kaolinite present as well.

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