Fly ash from coal-fired power plants

Statement 1 is correct; fly ash can be used in brick production as a partial replacement for clay, improving sustainability. Statement 2 is correct; fly ash is a pozzolanic material and can replace 15-30% of Portland cement in concrete while improving some properties. Statement 3 is incorrect; fly ash contains not only silicon dioxide and calcium oxide but also contains toxic elements like heavy metals (arsenic, mercury, lead, chromium), iron oxide, and alumina. This is why safe handling and utilization practices are important. The composition varies depending on the coal source. Fly ash utilization is important for waste management. > Fly ash: Bricks ✓, Concrete substitute ✓, but contains toxic elements ✗. Answer: (a).