Properties and Components of Cenospheres

A cenosphere is a lightweight, hollow sphere made largely of silica and alumina and filled with air, metals, or gas. The Cenospheres are manufactured as a byproduct of coal combustion at thermal power plants. Cenosphere-based compounds were fabricated and categorized for their structural and mechanical properties such as tensile, flexural, impact and vibrant mechanical properties such as storage and loss moduli as a function of temperature. The structural qualities were characterized by Scanning Electron Microscopy (SEM) and Wide-Angle X-ray Diffraction (WAXD) though the thermal characterizations were prepared by conducting Differential Scanning Calorimetric (DSC) and Thermo-Gravimetric Analysis (TGA). The DSC studies revealed that increase in cenosphere content has resulted in a decrease in crystallinity of the composites.

The amount of separation in retrieving the Cenospheres from coal fly ash has been valued for both wet and dry separation processes through applying the terminal velocity concept of particles. The diameter and density of the particle are determined by sieving industrial cenospheres and coal fly as type IV. Depending on the estimation, the dry separation process executed similarly to the wet separation process, with a most favorable Newton's efficiency of 0.54, just slightly lower than that of the wet separation process of 0.6. 

The mortar cubes can be made with a combination of Cenospheres and silica fume as a standby for the cement. The test on mortar cubes shown that cement loses its strength because of the replacement of cenosphere, but the loss can be calm down by adding silica fume to it. The strength decrement decreases by ages, displaying that the strength attainment is reduced by the addition of cenosphere. The microstructure has also been studied to show the disintegrated structure on advanced replacement of cenosphere. It was also noted that the hydration products react with cenospheres and, due to this; decline in the quantity of portlandite was witnessed resulting in strength decrement.