Industrial Extraction of Iron in the Blast Furnance

Iron is extracted from its ore, hematite, in the blast furnace.
The blast furnace is a large structure, lined with refractory bricks, where iron ore, coke and limestone are dumped into the top, and preheated air is blown in the bottom.
Coke, C, burns in the blast of hot air to form carbon dioxide, C + O2 -> CO2.
Carbon dioxide in the furnace is reduced to carbon monoxide: CO2 + C -> 2CO. This is responsible for reducing the iron oxide present in the iron ore into molten iron.
Iron(III) oxide is reduced to iron by carbon monoxide: Fe2O3 + 3CO -> 2Fe + 3CO2.
The limestone acts as a flux and reacts with the impurities in the iron ore to form slag: CaCO3 -> CaO + CO2; CaO + SiO2 -> CaSiO3 (slag).
Both the molten iron and slag collect at the bottom of the furnace. The less dense slag floats on the surface of the iron. Both can be tapped off separately.
The molten iron is then used to make steel, or is cast into forms known as pig iron. This pig iron is an intermediate step on the way of producing steel and is produced in a blast furnace.
The chemical reactions inside the blast furnace remain the same at any given height. The temperature gradually decreases from bottom to top.
Waste gases escape from the top of the furnace. These are used to heat incoming air or for other processes.
The whole system is designed for iron production on a large scale in a continuous process.
It is a cost-effective method of extracting iron as it uses low-cost materials (iron ore, coke, and limestone), recycles waste gases, and produces high quantities of iron.
However, it has significant environmental impacts such as air pollution from the release of gases and disruption of the local ecosystem due to mining activities.

Remember to practise using balanced chemical equations, and understand each step of the process to ensure complete understanding of how the blast furnace works. This will assist in answering any theoretical or practical application questions about the extraction of iron.