Common refractory fillers can be divided into three categories according to its physical and chemical properties: clay, silica and alumina.
Clay
Clay, also known as claystone, is the most common refractory raw material in refractory materials. Pure clay is composed of pure clay minerals, kaolinite and montmorillonite. It is a hydrated aluminum silicate.The clay has stable physical and chemical properties and good plasticity. Therefore, it can be used to make bricks and castables with large variety of shapes and sizes,It is also used for Spalling and thermal shock resistant linings, gunning and shotcrete.
Silica
Silica refers to a group of silicate minerals composed of silica and oxygen, in general,is a white or colorless powder. Silica has high fire resistance, high refractoriness,high chemical stability and good thermal shock resistance,it is usually used as a binder of alumina or sodium silicate.it also can be used in the manufacture of ceramic products such as insulation bricks, glass and cement.
Alumina
Alumina is an oxide of aluminum. It is widely used in the manufacture of refractory materials due to its excellent chemical stability and high fire resistance. Alumina is usually used as a densifying agent and the main component of a number of high-temperature thermal insulation materials.It can also be used in a variety of castable and plastic forming products,from small to large parts,from simple pre-cast shapes to complex molds.
Conclusion
In conclusion, the three common refractory fillers have unique physical and chemical properties and can be used in refractory manufacturing. Clay can be made into a variety of shapes and sizes, and can be used for Spalling and thermal shock resistant linings, gunning and shotcrete. Silica has high chemical stability and good thermal shock resistance and alumina has excellent chemical stability and high fire resistance. Therefore, these three common refractory fillers are used in many industries and play an irreplaceable role.
