What is the main reaction occurring in the blast furnace during extraction of iron from haematite?

Fe₂O₃ + 3CO → 2Fe + 3CO₂

The correct answer is option 1. \(Fe_2O_3 + 3CO \longrightarrow 2Fe + 3CO_2\).

Out of the listed reactions, the main reaction occurring in the blast furnace during extraction of iron from haematite is:

\(Fe_2O_3 + 3CO \longrightarrow 2Fe + 3CO_2\)

Hematite \((Fe_2O_3)\) is the most common iron ore used in blast furnace processes. Carbon monoxide \((CO)\) is the primary reducing agent in the furnace, generated from the reaction of coke (carbon) with preheated air. The given reaction depicts the reduction of iron oxide \((Fe_2O_3)\) by carbon monoxide \((CO)\) to produce elemental iron \((Fe)\) and carbon dioxide \((CO_2)\). This is the key reaction for extracting iron from hematite in a blast furnace.

Let us analyze the other options:

2. \(FeO + SiO_2 \longrightarrow FeSiO_2\): This reaction represents the formation of iron silicate slag, a by-product in the process. It removes impurities (gangue) like silicon dioxide \((SiO_2)\) from the molten iron.

3. \(Fe_2O_3 + 3C \longrightarrow 2Fe + 3CO\): While carbon \((C)\) can also act as a reducing agent, using \(CO\) is generally more efficient due to its higher reactivity with iron oxide.

4. \(Fe_2O_3 + CO_2 \longrightarrow FeCO_3\): This reaction is not typically favored in the high-temperature environment of a blast furnace. Carbon dioxide \((CO_2)\) can actually act as an oxidizing agent under these conditions.

The reaction between \(Fe_2O_3\) and \(CO\) is the principal process for reducing iron oxide to metallic iron during blast furnace extraction.