The global fly ash microspheres market is expected to register growth over the forecast period. Fly ash microspheres or cenospheres are hollow spheres made from silica and alumina with air or inert gas fillings and are by-products of coal combustion in thermal power plants. Fly ash microspheres or cenospheres have an average compressive strength of more than 3,000 psi and are available in sizes ranging from one to 500 microns. Superior properties such as insulation, waterproof, hardness, and rigidity make these useful in applications including fillers in cements, metals, and polymers to make composite materials, conductive coatings, tiles, fabrics, antistatic coatings in paints and electromagnetic shielding. Fly ash is produced when coal is burned in thermal power plants which consist mainly of ceramic particles such as silica and alumina. Structure and composition of fly ash depend on the composition of coal being used in power plants.
Cenospheres display characteristics such as low water absorption, resistance to acids, high particle strength, low thermal conductivity, ultra low density making them useful in improving properties of finished consumer products. Initial applications of fly ash microspheres comprised of extender for plastic compounds due to compatibility with urethanes, phenolic resins, epoxies, polyesters, latex, thermoplastics, and plastisols. In addition, it was also used in synthetic foams, specialty cements, and building materials such as composites and coatings, fire and heat protection devices, paints, marine craft bodies, automobile bodies, insulations, and sports equipment. The demand for cenospheres is expected to increase owing to increasing application areas coupled with abundant availability of raw materials from existing and new thermal power plants. Increase in the end-use market applications such as ceramics, plastic, construction, recreation, automotive, and energy and technology to further boost demand for fly ash microspheres market. Technological intensive nature of the manufacturing process is expected to result in strategic partnerships between manufacturers and buyers for improved application scope.
High initial investment as a result of technology intensive processes is expected to be an entry barrier in the market. It is estimated that fly ash from thermal plants consists of around 1% of cenospheres and float in lagoons which hold discharged fly ash due to low density and hollow nature. Further, cenospheres are isolated by froth flotation and dried and final extraction process is carried out which consists of a pneumatic conveying system connected to a triboelectric separator. Fly ash is then divided into three fractions in the tribo separator where cenospheres are separated from carbon and iron and graded for different end uses.