FLY ASH

Fly ash, also known as "pulverised fuel ash" in the United Kingdom, is one of the residues generated by coal combustion, and is composed of the fine particles that are driven out of the boiler with the flue gases. Ash that falls in the bottom of the boiler is called bottom ash . 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 boiler is 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) ( bothamorphous and crystalline),aluminium oxide (Al2O3) and calcium oxide  (CaO), the main mineral compounds in coal-bearing rock strata.
Chemical composition and classification
 
 Class F Fly Ash
 Class C Fly Ash

USES OF FLY ASH

 fly ash reuse:

1) Portland Cement
2) Embankment
3) Soil Stabilization
4) Flowable Fill
5) Asphalt concrete
6) Geopolymers
7) Roller compacted concrete
8) Bricks
9) Metal Matrix composites
10) Waste treatment and stabilization
11) As a catalyst

SPECIFICATIONS OF FLY ASH

Sr_No                             Parameters / Composition                                        Percentage

01                                       Calcium oxide (CaO)                                                      2% Max

02                                       Silicon di Oxide (SiO2)                                                   52-60 %

03                                       Aluminum Oxide (Al2O3)                                              24-30 %

04                                       Iron Oxide (Fe2O3)                                                           6% Max

05                                       Magnesium Oxide (MgO)                                                1% Max

06                                       Sulphuric Anhydride (SO3)                                             1% Max

07                                       Sulphide Sulphur                                                              1% Max

08                                       Loss of Ignition (LOI)                                                        5% Max

09                                       Fineness                                                                            3000 cm2/gm.Min

10                                        Sodium Oxide (Na2O)                                                      0.5% Max

11                                         Pottassium Oxide (K2O)                                                  0.5% Max