Explanation:

Fly ash is an unwanted unburnt residue of coal combustion in a coal thermal power plant. 

• It is emitted along with flue gases during the burning of coal in a furnace and collected using the electrostatic precipitators.
• The fly ash collected with the help of precipitators is converted into a wet slurry to minimise fugitive dust emissions.
• It is then transported to the scientifically designed ash ponds through slurry pipelines.
• Composition: Fly ash includes substantial amounts of silicon dioxide (SiO2), aluminium oxide (Al2O3), ferric oxide (Fe2O3) and calcium oxide (CaO). 
• Uses: It is used in concrete and cement products, road base, metal recovery, and mineral filler among others.

Hence only statement 2nd is correct.