Like fly ash, cenospheres are naturally occurring by-products of the burning process at coal-fired power plants. Unlike fly ash though, cenospheres are lightweight, inert, hollow spheres comprised largely of silica and alumina and filled with air and/or gases. Since they are inert, they are not considered a pozzolan. And because they are very small and have high compressive strengths, cenospheres can be used as structural lightweight filler.
Cenosphere from India has some general properties:
- Chemical Properties:
- Silica: 48% – 74%
- Alumina: 26% – 45%
- Iron: 1.5% – 4.00%
2 Physical Properties:
- Size: 75-400 microns
- Bulk Density: 0.20-0.25 grams per cubic centimeter (g/cc)
- Specific Gravity: <0.4 g/cc
- Compressive Strength: ~90% survival @ 2500psi
- Softening Point: 1040 degrees C
- Color: Light tan
Cenosphere from India can be studied through Chemical engineering. The progress of the Cenosphere Enhancement and Optimization Project is an initiative that seeks to improve existing methods of cenosphere extraction. Cenosphere is primarily used to create lightweight cement. It is also a good filler for polymers and its benefits are well-noted, particularly in the construction industry. Cement made with cenosphere is much lighter and this eases the burden shouldered by construction workers on a daily basis.
How cenosphere from India are produced?
Cenospheres are produced in very large amount in thermal power plants. They are always looked upon as fillers used to reduce the density and cost of the polymer. If cenosphere particles are allowed to remain properly dispersed by taking it in lower concentration, significant improvement in its mechanical, thermal, electrical, crystallinity, colorimetric and morphological properties are expected. To make it happen, epoxy/cenosphere composites were prepared, having lower concentration of cenosphere. Concentration of cenosphere in epoxy, cured with triethylenetetramine, was changed as 0, 3, 5, 7 and 10. Tensile Strength, Tensile Modulus, Percentage Elongation at Break and Crystallinity decreased, whereas, Flexural Strength and Flexural Modulus were found to have increased by 50% and above 100% respectively at 7 phr loading of cenosphere in epoxy. Thermal and electrical stability also increased with increase in concentration of cenosphere in the epoxy; however, the samples became blackish with increased addition of cenosphere. Using SEM analysis it was found that, cenospheres were properly and uniformly dispersed at 7 phr concentration and formed aggregates at 10 phr concentration.