1. Which mixture forms the charge added at the top of a blast furnace?

a) Sinter (from iron ore), coke and limestone
b) Iron scrap, oxygen and flux
c) Bauxite, cryolite and coke
d) Copper ore, coke and limestone

2. Hot air enters the furnace through large nozzles near the base called…

a) Stoves
b) Hoppers
c) Tuyeres
d) Scrubbers

3. Which equation shows the main reduction step producing molten iron?

a) C + O₂ → CO
b) Fe₂O₃ + 3CO → 2Fe_(l) + 3CO₂
c) Fe₂O₃ + 3CO₂ → 2Fe + 3CO
d) CaCO₃ → CaO + CO₂

4. Coke is mostly .

5. Limestone decomposes in the furnace to form oxide (CaO) and dioxide (CO₂).

6. The hottest region of the blast furnace typically reaches approximately…

a) 500⁰C
b) 200⁰C
c) 4000⁰C
d) 1600⁰C

7. Why does slag float on top of molten iron?

a) It is magnetic
b) It is less dense than molten iron
c) It has a higher melting point
d) It is insoluble in iron

8. Which statement about the gases leaving the top of the furnace is correct?

a) They are pure oxygen and hydrogen
b) They are only carbon monoxide
c) They are mainly nitrogen with carbon dioxide
d) They are mostly chlorine gas

9. The hot air nozzles are called .

10. Which statement about the blast furnace is NOT correct?

a) Molten iron floats on top of the slag
b) It runs as a continuous process
c) Molten iron is tapped from the base
d) Slag can be used in construction