A cenosphere is a lightweight, inert, hollow sphere which is made largely of silica and alumina filled with air and inert gas. Typically, cenosphere India is produced as a byproduct of coal combustion at thermal power plants. Usually, the color of this byproduct varies from gray to almost white, having a density of about 0.4 to 0.8 g/cm3 which gives them a great buoyancy. Combustion is a high-temperature exothermic redox chemical reaction of a fuel and an oxidant, generally, atmospheric oxygen producing oxidized in a mixture of a chemical reaction is termed as smoke. Burning in a fire producing flame, the heat produced can make combustion self-sustaining. This often goes through a complicated sequence of elementary radical reactions. That is solid fuels including wood primarily undergo endothermic pyrolysis to produce gaseous fuels where combustion is supplied to produce more heat.
The particles of Cenosphere India are hard, rigid, innoxious, lightweight, waterproof, and insulative making them highly useful for a range of products, notably as fillers. Filler particles are mixed with materials such as composite material, plastics, and concrete to lower the consumption and improve some properties of the mixture. Globally more than 555 million tons of fillers are used annually for different applications including paper, paint and coatings, plastics, rubbers, concrete, adhesives, and sealants. Cenospheres are also used widely as fillers in cement for producing low-density concrete. In recent years, manufacturers also started using cenospheres for filling metals and polymers to make them lightweight composite materials with enhanced strength than other types of foam materials. These composite materials are known as syntactic foam. Aluminum-based syntactic foams are widely used in the automotive sectors.
The combustion at thermal power plant takes place at the temperature of 1500o to 1750o C (2730o to 3180o F) through complicated physical and chemical transformation. However, the chemical composition and structure of Cenosphere India considerably depends on the composition of coal then generated. Basically, the ceramic particles produced in fly ash have three type of structure:
- Precipitator (solid)
- Cenospheres (hollow)
- Plerospheres (hollow with large diameter)