What is a refractory and why is it required?

Refractory is a material which can withstand high temperature and does not fuse. Examples are: fireclay, alumina, magnesite, chrome magnesite, dolomite etc.
Refractory materials are produced to meet the diversified requirements of high temperature processes carried out in metal extraction, cement, glassmaking, manufacturing, ceramic etc. industries. The refractory is required

• To allow thermal energy dependent conversions of reactants into products because metallic vessels are neither suitable nor economical
• Source of energy in high temperature processing is mostly fossil fuels either directly or indirectly i.e. electricity derived from fossil fuels. Thus refractory should minimize heat losses to conserve energy resources.
• Because the reaction chamber is constructed of refractory material, refractory is required to sustain the physico-chemical attack of different phases at different intervals of time during processing.