Talk:Refractory

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Refractory From Wikipedia, the free encyclopedia Jump to: navigation, search This article is about heat resistance. For other uses, see Refractory (disambiguation). Refractory is the quality of a material to retain its strength at high temperatures. Refractory materials are used to make crucibles and linings for furnaces, kilns and incinerators. There is no clearly established boundary between refractory and non-refractory materials, though a practical requirement often cited is the ability of the material to withstand temperatures above 1100 °C without softening.

[edit] Refractory materials Main article: Refractory metals Refractory materials must be strong at high temperatures, resistant to thermal shock, chemically inert, and have low thermal conductivities and coefficients of expansion.

The oxides of silicon (silica), aluminum (alumina), magnesium (magnesia), and calcium (lime) are the most important refractory materials, though fireclay (an aluminosilicate of varying composition) is widely used as well. Zirconia is used when the material must withstand extremely high temperatures. Silicon carbide is another refractory material. It is very strong at high temperatures, but will burn in the presence of oxygen, if the protective silica coating comes off. Refractories must be chosen according to the conditions they will face. For example, carbon cannot be used when it will be in contact with oxygen, as it will burn.

[edit] Types of refractories Acidic refractories cannot be used in a basic environment and basic refractories cannot be used in acidic environment because they will be corroded. Zircon, fireclay and silica are acidic, dolomite and magnesite are basic and alumina, chromite, silicon carbide, carbon and mullite are neutral. Refractory metals are also frequently used.

[edit] Refractory Anchorage Anti-abrasion refractory attached to pipes, chambers, etc, will require anchorage systems such as wire formed anchors or formed metal to support the refractory linings.

Retrieved from "http://en.wikipedia.org/wiki/Refractory"

[edit] All she wrote?

Having been a lifetime reader of encyclopedias, I'm often impressed with Wikipedia articles for the detail they provide. For example, the summary of the novel "The Dosadi Experiment" is wonderful, as is the article on Mortification of the Flesh. This article, however, seems far too sparse. It also seems to contain inaccuracies. For example, where did the idea originate that calcia and magnesia are the two most important refractories? Aluminosilicates are far more widely used - they're the basis of most firebrick, all insulating firebrick (IFB), and nearly all ceramic wool materials. Next to aluminosilicates, the most important refractory materials would have to be alumina and silica separately. Magnesia and calcia are way down on the list.

Considering that refractories are necessary in the manufacture of practically everything our society depends on, including our steel, aluminum, glass, and petroleum, I should think a more expansive and detailed article would be indicated. Cumbre 14:56, 20 July 2007 (UTC)

I work for a brick factory building corporation. In addition to not being a distinction between the temperature at which something becomes categorized as a refractory, here, some materials are refractory (such as the hard pressed kiln car surface blocks, made from cordierite, Mullite, and alumina..) but the fiber insulation blankets are by some not considered to be a "refractory" due to its soft nature, or something? As a ceramic engineer with many years in industry, I classify all ceramics as refractory, but, the ones used as insulation or kiln wall and car materials to be "refractories". Also, having supported the steel industry over the years, The handling equipment (those big buckets, lids, pouring chutes, etc)I consider as refractories, but, the steel parts that work only a lifting function, using regular materials are not refractory, but, if the material were selected to handle the heat, I would say it to be "refractory". So, I guess I consider materials that are selected for their application to handle the temperature of the evironment, and perform a function to be refractory materials, although they may not be considered "refractories". Steels(metals), carbon(organic), ceramics (inorganic-