A refractory material is one that retains its strength at high temperatures. Refractory materials are 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. 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. Today, the iron- and steel-industry uses approximately 70% of all refractory produced. 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 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 refractory materials.

A refractory material is one that retains its strength at high temperatures. Refractory materials are 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. 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. Today, the iron- and steel-industry uses approximately 70% of all refractory produced. 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 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 refractory materials.