Blast Furnace Iron Extraction Process

Steps:

• Air provides oxygen that reacts with coke (carbon) to form carbon dioxide, which reduces to carbon monoxide for iron oxide reduction.
• Limestone decomposes to calcium oxide, reacting with silica impurities to form slag.
• Molten iron, being denser, sinks below the lighter slag layer at the furnace base.
• Silicon dioxide acts as an acidic oxide, neutralized by basic calcium oxide from limestone.

Why A is correct:

• Air's oxygen reacts with carbon in coke via 2C + O₂ → 2CO, producing CO that reduces Fe₂O₃ to Fe.

Why the others are wrong:

• B: Molten iron is denser than slag, so it forms the bottom layer with slag on top.
• C: Limestone decomposes to CaO (CaCO₃ → CaO + CO₂), but CaO then reacts with SiO₂ to form slag, not directly producing it.
• D: Silicon dioxide is an acidic oxide, not basic, as it reacts with bases like CaO.

Final answer: A