Q. Consider the following statements regarding fly ash, a byproduct from coal-based thermal power plants:
1.It can be utilised in the manufacturing of building materials such as bricks.
2.It can partially replace Portland cement in concrete production.
3.It consists only of silicon dioxide and calcium oxide and is free from toxic substances.
Which of the statements given above is/are correct?
Answer: A
Notes:
Explanation:
- Fly ash is commonly used in making bricks, blocks, and tiles due to its pozzolanic properties.
- It can replace a portion of Portland cement in concrete, improving workability and durability.
- Fly ash is not made up of only silicon dioxide (SiO₂) and calcium oxide (CaO); it also contains other oxides and can have toxic elements like arsenic, lead, and mercury, depending on the coal source and combustion process.
Source: Environment (N.C.E.R.T)
