The word refractory implies resistant to melting or fusion. In technology, refractory refers
to those materials which are used to withstand the effect of thermal, chemical and physical
effects that do not melt during furnace procedures, whenever very high temperature is
involved, for example, in furnaces, kilns and electrical heating apparatus. Refractories are
the materials with high melting point and resist heat between low and high temperatures.
The refractories provide the linings, supports and other laments. Thus refractories are those
materials which are used for the construction of furnaces, kilns, ovens, crucibles and retorts
etc. This is on account of their resistance to heat when they are subjected to the cutting action
of ue gases, sudden changes in temperature and to the in uence of slags. Refractories are
sold in the form of bricks, silica, magnesite, chromite, magnesite-chromite bricks, silicon
carbide and zirconia refractories etc. The uxes required for binding together the particles of
the refractories are kept at a minimum in order to reduce vitri cation.