Which of the following ores can be concentrated using froth floatation process?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Copper pyrites
Froth floatation is used for sulphide ores: collectors such as pine oil make the sulphide particles wetted by oil, so they rise with the froth while the gangue is wetted by water and sinks. Copper pyrites, CuFeS2, is a sulphide ore of copper.
Why the other options are incorrect
Option (1) Magnetite, Fe3O4 — Incorrect. An oxide that is magnetic; it is concentrated by magnetic separation.
Option (2) Calamine, ZnCO3 — Incorrect. A carbonate ore, not a sulphide.
Option (4) Bauxite, Al2O3·xH2O — Incorrect. An oxide ore concentrated by leaching with NaOH.
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Froth Floatation Method
