Extraction of Iron from Haematite in a Blast Furnace

Introduction to Iron Extraction

Iron is extracted from its ore, haematite (Fe_2O_3) , using a blast furnace. This process involves several steps and chemical reactions to produce iron, which is a crucial material in various industries.

The Blast Furnace Process

A blast furnace is a large, steel structure lined with heat-resistant bricks. It operates continuously and involves the following steps:

• Charging: The furnace is charged with iron ore (haematite), coke (a form of carbon), and limestone (calcium carbonate).
• Combustion: Hot air is blown into the furnace, causing the coke to burn and produce carbon dioxide (CO_2) .
• Reduction: The carbon dioxide reacts with more coke to form carbon monoxide (CO) , which reduces the iron ore to iron.
• Formation of Slag: Limestone decomposes to form calcium oxide, which reacts with impurities to form slag.

Chemical Reactions in the Blast Furnace

• Combustion of coke: $$C + O_2 \rightarrow CO_2$$
• Formation of carbon monoxide: $$CO_2 + C \rightarrow 2CO$$
• Reduction of iron ore: $$Fe_2O_3 + 3CO \rightarrow 2Fe + 3CO_2$$
• Formation of slag: $$CaCO_3 \rightarrow CaO + CO_2$$ $$CaO + SiO_2 \rightarrow CaSiO_3$$

Products of the Blast Furnace

The main products are:

• Molten Iron: Collected at the bottom of the furnace and used to produce steel.
• Slag: Used in road construction and as a raw material for cement.