HISTORY

Refractories have been used by humankind since earliest history.  When humans first began to smelt metals and shape primitive knives, hunting weapons, and ornamental rings and jewelry, crude refractory materials were developed to facilitate the pyroprocessing of the ores.  As refractory practice developed, materials evolved which were ever more durable, lasting longer and longer before replacement was necessary.
 
DEFINITION

Refractory materials are materials, which have the capacity to withstand high temperature without melting or decomposing, and the capacity to remain unreactive and inert when exposed to severe environments.  Some refractory products are Magnesia and Alumina with melting points of 28000C and 20400C respectively.  Also hafnium carbide HfC with melting point of 41500C, it has the highest melting point of any known material.