Refractory is defined as the quality of a material to retain its strength at higher temperature. These materials are used inside the furnaces, kilns incinerators and reactors.
These materials should be chemically and physically stable at higher temperature. They must be resistant to the thermal shock. They should be chemically inert and have specific values of thermal conductivity and coefficient of thermal expansion.
Classification of Refractories
On the basis of chemical compositions refractories are classified in to three categories.
- Acidic refractories
- Basic refractories
- Neutral refractories
These refractories are made up of Zircon, fire clay and silica
These refractories are made up of Dolomite and Magnetite
These refractories are made up of alumina, chromites, silicon carbide and mulite. We cannot use acidic refractories in basic environment and basic refractories in acidic environment because they will be corroded.
Classification of refractories on the basis of temperature range
When the temperature is between 1580 - 1780░c, it is known as refractory. E.g. fire clay
When the temperature is between 1780-2000░c, it is known as high refractory. E.g. Chromites
When the temperature is > 2000░C, it is known as Super refractory. E.g. Zircon
|← Types of Compressors - Centrifugal, Reciprocating, Screw, Rotary Compressors||Furnace - Types of Furnaces | Classification of Furnace →|