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Fire Brick Facts

Withstanding temperatures of 4,000 degrees Fahrenheit is by no means an unimpressive feat. Firebrick is used as a heat-resistant material that can line areas that are commonly subjected to flames or high temperatures. Although homeowners commonly overlook firebrick that is within their own homes, it is one of the technologies that makes modern home conveniences possible.

Uses
- Firebrick has a special durability that allows it to withstand high temperatures and still maintain structural stability; therefore, firebrick is used in situations where strong heat will be present. The most common areas that firebrick is used is within fireplaces, as well as fireplace flues. They can also be found in homes with built-in furnaces, or even very old homes with antique ovens. Steel and iron industries---especially in the past---commonly used firebrick as well.
Types
- Contrary to the name implication, firebrick is a general term that encompasses several types of fire-resistant materials. Clay bricks---also known as fireclay---is one of the most common types of firebricks. Another type of firebrick is one that's made of silica, which has an even higher melting point than fireclay. High alumina bricks are also commonly used, and magnesite bricks are used due to their ability to withstand alkalis.
Melting Point
- All firebrick types have extremely high melting points. Fireclay can withstand temperatures up to 2,800 degrees Fahrenheit. Silicon carbide can reach temperatures of 4,000 degrees Fahrenheit---which is why it is also often used for industrial furnaces.
Insulation
- Insulation is one of firebrick's weak areas. Most types of firebrick are extremely poor insulators and therefore need another type of material included with installation. Many firebricks use an insulating material known as "highly porous fireclay" or "kaolin." This material has a lower melting point of around 1,600 degrees Fahrenheit and heats very quickly, which allows it to be a great insulator.
History
- One of the first major companies to produce firebricks was the Niles Fire Brick Company---based in Ohio. The company was established by John Thomas, a British immigrant. The company focused on building and supplying firebrick---also called refractory brick at the time---for furnaces that were used by iron and steel companies. The plant produced firebrick for nearly a hundred years until it closed down in the 1960s.

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