Refractories for Industrial Furnaces and Kilns
There is a wide variety of refractory compositions fabricated, but alumina, silica and magnesia are most commonly used. Zirconia is used when the material must withstand very high temperatures. These refractories are used in acidic atmospheres where they’re not attacked by alkalis. In an oxygen-free atmosphere - and to withstand extreme high temperature - silicon carbide or graphite is used as a refractory.
Many standard refractory products resemble a typical construction brick. However, there are many different shapes and forms because they may be used to construct an arch or form a round opening in a furnace.