Refractory Materials

                                              Refractor Materials, are ceramic materials that has an unusually high melting point and that maintains its structural properties at very high temperature. 

According to ASTM (American Society for Testing and Materials) the definition of Refractories is:

                        It's a non-metallic materials having those chemical and physical properties that made them applicable for structure or as components of system, that are exposed to environments above 1000 °F / 500 °C. 

Refractories are to 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.

Refractories are used in high temperature processes because of their heat resistant properties and stability at high temperatures. They are normally used as linings for high-temperature furnaces and other processing units such as kilns, incinerators and reactors since they are able to withstand physical wear, high temperatures, and corrosion by chemical agents. They are also used to make crucibles. They find extensive uses in iron and steel industry. Refractories are also employed in great quantities glassmaking industries, power plant, fertilizer industries and cement industries, where they are formed into a variety of shapes to line the interiors of furnaces, kilns, and other devices that process materials at high temperatures. 

  

As above photo indicates refractories can come in various shapes and sizes and also it can be powdery forms. Refractories in shapes called as Refractory Bricks and Blocks. Refractories in un-shape form called as Refractory monolithic.