Question

The primary function of a blast furnace is to

• A. Produce steel directly
• B. Convert pig iron to steel
• C. Reduce iron ore to molten iron
• D. Remove carbon from iron

Hint:

Logic Tip: Remember the sequence: Dirt (Ore) $\rightarrow$ Blast Furnace $\rightarrow$ Pig Iron $\rightarrow$ Steel Furnace $\rightarrow$ Steel. The blast furnace's only job is getting the raw iron out of the dirt.

Answer 1

The Correct Option is C

Concept:
The blast furnace is the first, massive, foundational step in the steelmaking industry. Its sole chemical purpose is smelting—extracting elemental metal from raw, rocky ores mined from the ground.

Step 1: A blast furnace is fed from the top with raw iron ore (iron oxides like hematite), coke (carbon fuel), and limestone (flux).

Step 2: A blast of hot air is blown into the bottom. The carbon burns to form Carbon Monoxide ($CO$). This $CO$ acts as a reducing agent, physically stripping the oxygen atoms away from the iron oxide rock ($Fe_2O_3 + 3CO \rightarrow 2Fe + 3CO_2$).

Step 3: The result is a pool of liquid metal at the bottom called "pig iron" or molten iron.

Step 4: This pig iron contains about 4% carbon, making it brittle. It is not steel. Converting pig iron to steel (by removing that excess carbon) happens later in a different machine called a Basic Oxygen Furnace.

Step 5: Therefore, the blast furnace does not make steel; it reduces raw iron ore into impure molten iron.