Fly ash
Topic: Manufacturing Industries of India: Location and Distribution · NCERT: Class 10, Ch 6 "Manufacturing Industries"
Meaning
Fly ash is the fine, powdery ash left after coal is burnt, mostly in thermal power plants. It is carried up with the smoke and then caught. Fly ash, phosphogypsum (waste from fertiliser plants) and steel slag (waste from steel plants) are India's major industrial solid wastes. Dumped fly ash spoils land and water. But it can also be useful. It goes into bricks, cement and roads, and it is used to fill old mines. Rules made in 2021 require all of it to be used, which is called 100% utilisation.
Example
NTPC's Ramagundam power plant in Telangana manages its fly ash through ash use, ash ponds (places to store wet ash) and recycling of ash water. Blended cement also uses fly ash, which saves limestone.
Don't confuse with
- Bottom ash: the heavier ash that falls to the bottom of the furnace. Fly ash is the light ash that rises with the flue gas.