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A fire brick, firebrick, or refractory is a block of
ceramic
A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain ...
material used in lining
furnace
A furnace is a structure in which heat is produced with the help of combustion.
Furnace may also refer to:
Appliances Buildings
* Furnace (central heating): a furnace , or a heater or boiler , used to generate heat for buildings
* Boiler, used t ...
s,
kiln
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay int ...
s,
fireboxes, and
fireplace
A fireplace or hearth is a structure made of brick, stone or metal designed to contain a fire. Fireplaces are used for the relaxing ambiance they create and for heating a room. Modern fireplaces vary in heat efficiency, depending on the design.
...
s. A refractory
brick
A brick is a type of block used to build walls, pavements and other elements in masonry construction. Properly, the term ''brick'' denotes a block composed of dried clay, but is now also used informally to denote other chemically cured cons ...
is built primarily to withstand high temperature, but will also usually have a low
thermal conductivity
The thermal conductivity of a material is a measure of its ability to conduct heat. It is commonly denoted by k, \lambda, or \kappa.
Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal ...
for greater
energy efficiency
Energy efficiency may refer to:
* Energy efficiency (physics), the ratio between the useful output and input of an energy conversion process
** Electrical efficiency, useful power output per electrical power consumed
** Mechanical efficiency, a ra ...
. Usually dense firebricks are used in applications with extreme mechanical, chemical, or thermal stresses, such as the inside of a wood-fired kiln or a furnace, which is subject to abrasion from
wood
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin th ...
, fluxing from ash or
slag
Slag is a by-product of smelting (pyrometallurgical) ores and used metals. Broadly, it can be classified as ferrous (by-products of processing iron and steel), ferroalloy (by-product of ferroalloy production) or non-ferrous/base metals (by-prod ...
, and high temperatures. In other, less harsh situations, such as in an electric- or
natural gas
Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...
-fired
kiln
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay int ...
, more porous bricks, commonly known as "kiln bricks", are a better choice.
They are weaker, but they are much lighter and easier to form and
insulate far better than dense bricks. In any case, firebricks should not
spall
Spall are fragments of a material that are broken off a larger solid body. It can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure (as in a ball ...
, and their strength should hold up well during rapid temperature changes.
Manufacture
In the making of firebrick,
fireclay
Fire clay is a range of refractory clays used in the manufacture of ceramics, especially fire brick. The United States Environmental Protection Agency defines fire clay very generally as a "mineral aggregate composed of hydrous silicates of alumin ...
is fired in the kiln until it is partly
vitrified
Vitrification (from Latin ''vitreum'', "glass" via French ''vitrifier'') is the full or partial transformation of a substance into a glass, that is to say, a non-crystalline amorphous solid. Glasses differ from liquids structurally and glasses po ...
. For special purposes, the brick may also be glazed. There are two standard sizes of fire brick: and . Also available are firebrick "splits" which are half the thickness and are often used to line wood stoves and fireplace inserts. The dimensions of a split are usually . Fire brick was first invented in 1822 by
William Weston Young
William Weston Young (1776–1847) was a British Quaker entrepreneur, artist, botanist, wreck-raiser, surveyor, potter, and inventor of the firebrick.
Biography
William Weston Young was born on 20 April 1776 at Lewin's Mead, Bristol, England ...
in the
Neath Valley
The Vale of Neath (or Neath Valley, Welsh: ''Cwm Nedd''), one of the South Wales Valleys, encompasses the upper reaches of the River Neath in southwest Wales. In addition to the River Neath, it is traversed by the Neath Canal and the A465 dual ...
of
Wales
Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...
.
High temperature applications
The
silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...
fire bricks that line
steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
-making
furnace
A furnace is a structure in which heat is produced with the help of combustion.
Furnace may also refer to:
Appliances Buildings
* Furnace (central heating): a furnace , or a heater or boiler , used to generate heat for buildings
* Boiler, used t ...
s are used at temperatures up to , which would melt many other types of ceramic, and in fact part of the silica firebrick liquefies.
High-temperature Reusable Surface Insulation (HRSI), a material with the same composition, was used in the insulating tiles of the
Space Shuttle
The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program na ...
.
Non-ferrous metallurgical processes use
''basic'' refractory bricks because the slags used in these processes readily dissolve the "acidic" silica bricks. The most common basic refractory bricks used in smelting non-ferrous metal concentrates are "chrome-magnesite" or "magnesite-chrome" bricks (depending on the relative ratios of
magnesite
Magnesite is a mineral with the chemical formula (magnesium carbonate). Iron, manganese, cobalt, and nickel may occur as admixtures, but only in small amounts.
Occurrence
Magnesite occurs as veins in and an alteration product of ultramafic ro ...
and
chromite
Chromite is a crystalline mineral composed primarily of iron(II) oxide and chromium(III) oxide compounds. It can be represented by the chemical formula of FeCr2O4. It is an oxide mineral belonging to the spinel group. The element magnesium can s ...
ores used in their manufacture).
Lower temperature applications
A range of other materials find use as firebricks for lower
temperature
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer.
Thermometers are calibrated in various temperature scales that historically have relied o ...
applications.
Magnesium oxide
Magnesium oxide ( Mg O), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions ...
is often used as a lining for
furnace
A furnace is a structure in which heat is produced with the help of combustion.
Furnace may also refer to:
Appliances Buildings
* Furnace (central heating): a furnace , or a heater or boiler , used to generate heat for buildings
* Boiler, used t ...
s. Silica bricks are the most common type of bricks used for the inner lining of furnaces and
incinerator
Incineration is a waste treatment process that involves the combustion of substances contained in waste materials. Industrial plants for waste incineration are commonly referred to as waste-to-energy facilities. Incineration and other high ...
s. As the inner lining is usually of sacrificial nature, fire bricks of higher alumina content may be employed to lengthen the duration between re-linings. Very often cracks can be seen in this sacrificial inner lining shortly after being put into operation. They revealed more expansion joints should have been put in the first place, but these now become expansion joints themselves and are of no concern as long as structural integrity is not affected.
Silicon carbide, with high abrasive strength, is a popular material for hearths of
incinerator
Incineration is a waste treatment process that involves the combustion of substances contained in waste materials. Industrial plants for waste incineration are commonly referred to as waste-to-energy facilities. Incineration and other high ...
s and cremators. Common red clay brick may be used for chimneys and wood-fired ovens.
See also
*
Harbison-Walker Refractories Company
Harbison-Walker Refractories Company originated as the Star Firebrick Company on March 7, 1865, with Articles of Association by a group of Pittsburgh and Allegheny residents. On January 30, 1875, Hay Walker Sr. and Samuel P. Harbison entered Articl ...
*
Equivalent VIII
''Equivalent VIII'', 1966, 120 Firebricks, 5 x 27 x 90 ¼ inches, occasionally referred to as ''The Bricks'', is the last of a series of minimalist sculptures by Carl Andre. The sculpture consists of 120 fire bricks, arranged in two layers, in a ...
*
Niles Firebrick Niles Firebrick was manufactured by the Niles Fire brick Company since it was created in 1872 by John Rhys Thomas until the company was sold in 1953 and completely shutdown in 1960. Capital to establish the company was provided by Lizzie B. Ward to ...
References
Further reading
*
{{DEFAULTSORT:Fire Brick
Bricks
Refractory materials
Silicates