Refractory materials must be chemically and physically stable at high temperatures. Depending on the operating environment, they must be resistant to thermal shock, be chemically inert, and/or have specific ranges of thermal conductivity and of the coefficient of thermal expansion.
Based on fusion temperature
Refractory materials are classified into three types based on fusion temperature (melting point).
- Normal refractorieshave a fusion temperature of 1580–1780 °C (e.g. Fire clay)
- High refractorieshave a fusion temperature of 1780–2000 °C (e.g. Chromite)
- Super refractorieshave a fusion temperature of > 2000 °C (e.g. Zirconia)
Zircon is used in a wide range of refractory applications, including specialty castings and ceramics, where its resistance to high temperature and abrasion makes it extremely valuable in the manufacturing processes. In the refractory industry, it is mainly used as a raw material for bricks, mortars, furnace linings and castables. In the ceramic industry, its opacity and hardness give a whiteness and durability to tiles, sanitary ware and tableware. It’s also utilized in a range of other high-tech industrial and chemical applications.