What Are Fire Bricks?

What Are Fire Bricks?

Fire bricks are refractory bricks that are used in a variety of applications.fire bricks These include fireplaces and the inner lining of kilns, furnaces, and similar structures that require heat resistance at high temperatures. They are made of clay-based materials and are fired until partially vitrified. They are able to withstand temperatures of up to 1700 deg C, making them ideal for a wide variety of high temperature applications.

The chemical composition of refractory bricks is typically 23 percent alumina and 73 percent silica.fire bricks Alumina is an important component because it has a much higher softening and fusion temperature than silica. This is essential because it gives refractory bricks the tensile strength needed to resist intense thermal stress.

Alumina is often mixed with other ingredients to form the brick’s internal binders and fluxes that help lower the softening and fusion temperature.fire bricks Lime, magnesia, and iron oxide are some of the common additives.

Another important component of refractory bricks is grog, which is a ground up, pre-fired clay that helps limit expansion and contraction that the fire brick goes through in heating and cooling cycles.fire bricks This allows for easier formation and reduces the chance of cracking.

These refractory bricks are manufactured by mixing a kiln-baked refractory clay with alumina and grog. The alumina helps give these bricks their refractory properties while the grog limits the amount of expansion and contraction they go through in heating and cooling cycles.

In addition to the alumina content of the fire brick, it may also have other added chemicals such as silica and kaolinite. Adding these chemicals can make the fire brick more durable, but can also change the color of the brick.

There are two main types of refractory bricks, which are referred to as soft or Insulation Brick and hard or Dense Brick. The soft bricks are lighter, easier to form and can withstand more heat than the dense bricks.

They are typically rated in terms of the maximum service temperatures at which they will work and may vary from grade to grade. These refractory bricks can be used for a variety of high temperature applications such as wood burning kilns and furnaces, salt and soda kilns, power plant fire boxes and more.

Most of the time, they are made from refractory fire clay, but it is possible to use other materials such as sand or cement. These alternative fire bricks are generally cheaper than refractory bricks and are also easier to install.

A typical fire brick is composed of a mixture of 50-75% refractory fire clay, with 20-40% alumina and a low amount of fluxing matter. This mix of refractory fire clay and alumina is usually made from natural clay or crushed clay, but can be mixed with different minerals to provide specific properties.

The alumina, silica and kaolinite content of the fire clay is determined by the type of application it will be used for. It is the combination of these three components that gives refractory bricks their high strength and ability to withstand extremely high temperatures.

Tags:fire clay brick | high alumina refractory bricks | insulation bricks