Refractory

A refractory material is one that retains its strength at high temperatures. ASTM C71 defines refractories as "non-metallic materials having those chemical and physical properties that make them applicable for structures, or as components of systems, that are exposed to environments above 1,000 °F (811 K; 538 °C)".

Refractory materials are used in linings for furnaces, kilns, incinerators and reactors. They are also used to make crucibles and moulds for casting glass and metals and for surfacing flame deflector systems for rocket launch structures.

Refractory materials

Refractory materials must be chemically and physically stable at high temperatures. Depending on the operating environment, they need to be resistant to thermal shock, be chemically inert, and/or have specific ranges of thermal conductivity and of the coefficient of thermal expansion.

The oxides of aluminium (alumina), silicon (silica) and magnesium (magnesia) are the most important materials used in the manufacturing of refractories. Another oxide usually found in refractories is the oxide of calcium (lime). Fire clays are also widely used in the manufacture of refractories.

Refractory (disambiguation)

Refractory is the quality of a material to retain its strength at high temperatures. Refractory may also refer to:

In materials

In biology

Other

Refractory (planetary science)

In planetary science, any material that has a relatively high equilibrium condensation temperature is called refractory. The opposite of refractory is volatile.

The refractory group includes elements and compounds like metals and silicates (commonly termed rocks) which make up the bulk of the mass of the terrestrial planets and asteroids in the inner belt. A fraction of the mass of other asteroids, giant planets, their moons and trans-Neptunian objects is also made of refractory materials.

Classification

The refractory elements can be divided into several categories: