A Cenosphere is a lightweight, inert, hollow sphere made largely of silica and alumina and filled with air or inert gas, typically produced as a coal combustion byproduct at thermal power plants at temperatures of 1,500 to 1,750 Celsius.
Their chemical composition and physical structure vary considerably depending on the burning process and the composition of coal with sizes varying between 5 and 500 Microns and varying chemical and physical properties.
Cenosphere grades can be classified into different categories according to their:
- Off White
- Light Grey
- Al2O3 Content
- SiO2 Content
- Fe2O3 Content
- K2O Content
- Na2O content
- Compressive Strength
Each grade of Cenespheres have different industrial applications such as and not limited to:
- Component in lightweight insulating
- Filler for paints, lacquers and plastics
- Light weight aggregate in concretes
Cenospheres are excellent in reduction of weight, increasing filler loading, reduction of shrinkage, reduction of viscosity, increased fireproofing, increased lubricity, increased refractoriness and transport savings.