Fly ash, also known as flue-ash, is one of the residues generated in combustion, and comprises the fine particles that rise with the flue gases. Ash that does not rise is called bottom ash. In an industrial context, fly ash usually refers to ash produced during combustion of coal. Fly ash is generally captured by electrostatic precipitators or other particle filtration equipment before the flue gases reach the chimneys of coal-fired power plants, and together with bottom ash removed from the bottom of the furnace is in this case jointly known as coal ash. Depending upon the source and makeup of the coal being burned, the components of fly ash vary considerably, but all fly ash includes substantial amounts of silicon dioxide (SiO2) (both amorphous and crystalline) and calcium oxide (CaO), both being endemic ingredients in many coal-bearing rock strata.
the past, fly ash was generally released into the atmosphere, but pollution
control equipment mandated in recent decades now require that it be captured prior to
release. About 43% is recycled, often used as a pozzolan to produce hydraulic cement
or hydraulic plaster or a partial replacement for Portland cement in concrete production.
Fly ash is known for environmental hazards, and its problems associated with disposal
and neutralization of polluting content of fly ash. In past few decades, R &D efforts were
undertaken and it has been proved that this material can be utilized in number of ways in
building construction products as well as in civil works with adequate durability.
Fly Ash is used in different ways
1) Manufacturing building construction products like Fly Ash Brick / Clay Bricks / Pavers /
Block etc.
2) Fly ash Cement/Fly ash as part replacement of cement
3) Roads & Embankments.
4) Fill / Reclamation of low lying area.
5) Stowing material for mine fill.
6) Construction of lagoon dykes , divide bunds.
1) Manufacturing building construction products like Fly Ash Brick / Clay Bricks / Pavers /
Block etc.
2) Fly ash Cement/Fly ash as part replacement of cement
3) Roads & Embankments.
4) Fill / Reclamation of low lying area.
5) Stowing material for mine fill.
6) Construction of lagoon dykes , divide bunds.