Cenospheres are light weight, inert hollow sphere comprising largely of silica & alumina and filled with air or inert gas. Cenosphere from India is naturally produced by the burning process of crushed coal-fired boilers. They are molded during the molten state of ash and reach spherical shape to have minimum surface. Inert gasses flowing along the burning gas stream also get locked inside the spheres. The bubbles caused by the inert gas combustion get into multiple forms with the frozen particles or in a concentric form, whose diameter is near the diameter of the particles.
The bubbles are found moving on the surface of fly ash. Cenosphere from India is unique free flowing powders composed of hollow, hard-shelled, and minute spheres. Cenospheres are formed from a small portion of the Pulverized Fuel Ash (PFA) which is produced from the burning of the coal in power stations. These are made up of iron, silica, and alumina. Generally, the size of the cenosphere particles ranges from 1 to 500 microns with an average compressive strength of above 3000 psi having a color variation from white to dark gray.
The factors included in the property of cenosphere are:
- Spherical shape
- Free flowing
- Hard electrical properties
- High melting point
- Low oil absorption
- Good packing application
- Versatile filler
These can be used for both commercial and industrial purposes for oil well cementing and PVC cushion vinyl flooring. However, Fillites are also used due to its unique property of chemical resistance, low density, and strengthening capacity. Fillites are used for the following applications:
- Latex Emulsions,
- Epoxy Resins; and
- Unsaturated Polyester Resins.
Most of the Cenosphere from India are restored from the ash ponds at the coal fire plants. It is a huge challenge for the Indian power sector to generate fly ash from the combustion of the coal, as the sector is dominated by coal. Today, around 53% of the total power capacity is based on the coal. Today, the country generates 160 million tons of fly ash, out of which only 80 million tons are being used.