The main constituent of fly ash is silica (SiO2), followed by alumina (Al2O3) and ferrous oxide (Fe2O3). Fly ash is a fine powder that is produced as a byproduct of coal combustion. It is a pozzolanic material, which means that it can react with lime to form cementitious compounds. Fly ash is used in a variety of applications, including concrete, grout, and plaster.
Aluminium oxide (Al2O3) is
a white, non-metallic solid that is the most abundant oxide in the Earth’s crust. It is a major component of bauxite, which is the ore from which aluminum is extracted. Aluminium oxide is also used in a variety of other applications, including ceramics, abrasives, and pigments.Ferrous oxide (Fe2O3) is a red-brown solid that is the most common iron oxide. It is found in nature as the mineral hematite. Ferrous oxide is also used in a variety of other applications, including steelmaking, pigments, and catalysts.
All of these materials are found in fly ash, but silica is the most abundant.