Guide to Aluminum Refractory Bricks

Aluminum brick is a common refractory material, and high alumina brick is the more familiar aluminum refractory brick. In addition to high alumina bricks, there are many other alumina bricks, today Fireramo summarizes the common alumina bricks, the characteristics of alumina bricks, as well as the composition and applications.

What is alumina brick?

Aluminum refractory brick is a special type of refractory brick, which is made of high-purity aluminum oxide (Al2O3) as the main component. Aluminum refractory bricks are widely used in high-temperature industrial kilns, metallurgy, glass and chemical industry because of their high temperature resistance and resistance to chemical attack.

Common aluminum refractory bricks

High Alumina Brick

The main component of high alumina bricks is alumina, with a content of more than 48%. This makes its refractoriness very high, which can generally reach 1750℃~1790℃, and the load softening temperature is also between 1400℃ and 1520℃.

According to the different content of Al2O3, high alumina bricks also have different grades such as Grade I, Grade II and Grade III. For example, Grade I high alumina bricks have an Al2O3 content of more than 75%, while Grade II high alumina bricks have an Al2O3 content of 65% to 70%, and Grade III high alumina bricks have an Al2O3 content of 55% to 60%; high alumina bricks with different grades are also different in terms of performance.

Mullite Brick

Mullite brick is a kind of refractory brick with mullite as the main crystal phase. Generally, the alumina content is between 65% and 75%. It is characterized by high temperature resistance, high strength and low thermal conductivity.

Corundum bricks

Corundum refractory bricks are made from raw materials with an alumina (Al2O3) content of 95% or more, and are therefore also known as high-alumina refractory bricks. Corundum bricks have excellent properties such as high temperature resistance, corrosion resistance, abrasion resistance, high strength and low thermal conductivity.

Andalusite Brick

Andalusite Brick is a refractory brick compounded with rhodochrosite and mullite as raw materials, which has good oxidation resistance, strong refractoriness, high compressive strength, and low specific gravity, good peeling resistance, high temperature flexural strength and long service life.

High Alumina Lightweight Brick

High-alumina lightweight bricks, also known as high-alumina insulating bricks, mainly contain high-alumina poly-light ball bricks and high-alumina mullite bricks. These bricks have an alumina content of 48% or more, and are mainly lightweight refractories composed of mullite and glass phase or corundum together.

Aluminum Bubble Brick

Aluminum Bubble Brick is a lightweight, insulating aluminum refractory brick usually composed of alumina and a blowing agent. It has low thermal conductivity and good thermal insulation properties, and is commonly used in furnace walls, roofs and bottoms to reduce heat loss.

Characteristics of aluminum refractory bricks

Good refractoriness
Aluminum refractory bricks have good resistance to high temperatures and can withstand thermal stress and thermal cycling in high temperature environments.

Chemical resistance
Aluminum refractory bricks have good erosion resistance to a variety of chemicals and can maintain stability in corrosive atmospheres or chemical media.

Good thermal shock stability
Aluminum refractory bricks have good thermal shock resistance and can maintain structural integrity under rapid temperature changes.

Low thermal conductivity
Some aluminum refractory bricks have low thermal conductivity, which can reduce heat conduction and provide thermal insulation.

Good mechanical properties
Aluminum refractory bricks typically have high strength and abrasion resistance, and can withstand mechanical stresses and material impacts.

Easy processing and installation
Aluminum refractory bricks are relatively easy to cut and process, and can be adapted to the needs of different shapes of equipment for easy installation and maintenance.

Composition of aluminum refractory bricks

Alumina: Alumina is one of the main components of aluminum refractory bricks, which has good refractoriness and chemical stability, and is able to withstand thermal stress and corrosion in high temperature environments.

Clay: Clay is a common additive used to increase the plasticity and formability of the refractory bricks, as well as to provide a certain degree of adhesion and refractoriness.

Siliceous materials: Siliceous materials are commonly used to adjust the chemical composition and improve the refractory properties of aluminum-based refractory bricks.

Silicate materials: Silicate materials are important binding agents in aluminum refractory bricks, which can promote the bonding between particles and form structural stability.

Additives: Some auxiliary materials, such as silicate water glass, quartz sand, graphite, etc., are often added to aluminum refractory bricks to improve the performance of refractory bricks, such as increasing wear resistance, thermal shock resistance and erosion resistance.

Application of aluminum refractory bricks

Aluminum refractory bricks possess good refractoriness and chemical stability, they can be used in the erection of various high temperature industrial furnaces, such as converters, electric furnaces, ladles, glass furnaces, combustion chambers, and other industrial furnaces. It should be noted that any furnace is not built with only one type of refractory bricks, but with different types of refractory bricks.