Cenospheres are sometimes also called as microspheres that are widely used in a variety of materials from plastics and caulking to paints and finishes. Although, they are sometimes also used in concrete. Cenosphere from India consists a range of uses in concrete countertops including:
- A lightweight aggregate – cenospheres can be treated as a substitute of the normal-weight sand that is used in concrete. They have a density that is less than water (approx. 0.7 vs water’s 1.0); quartz sand particles typically have a density of about 2.65 which means that 1 pound of cenospheres takes up the similar absolute volume as about 3.8 lbs of sand.
- A workability enhancer and extra-fine aggregate – Cenospheres are known for their very small spherical particles. As such they act just like minute ball bearings in a concrete mix. By adding cenospheres to a conventional weight concrete mix will increase workability because of its ball bearing effect and since they are also structural aggregate, they expand concrete density and strengthen it by providing a better packing. Furthermore, the added fines mend the trowelability and finishability. Usually dosages of 1% to 5% by weight of aggregate are added to a concrete mix to improve the workability.
- A bulk filler and shrinkage reducer in cement grouts – Meanwhile Cenosphere from India have very fine particles and are generally light in color; they are perfect for the use in cement grout slurry. By adding the bulk from the cenospheres, it not only increases the volume of grout without adding more cement, but also the fine aggregate gradation of the particles supports to reduce the shrinkage. In spite of everything, cement grout is still a kind of concrete, so the same rules apply. Finally, the spherical shape marks packing pinholes at ease and more effective because of the polishing action delivered by the particles. And the spherical shapes are further likely to “roll” into small holes better than pointed or angular crushed particles. Typical cenosphere measured quantity is approximately around 10% to 30% by weight of cement.
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.