The blast furnace is a special type of furnace that is used to make iron from its ore. The dimensions of the blast furnace can be up to 60 meters tall and 15 meters in diameter. It is the biggest chemical reactors and also high ovens. The blast furnace is built of steel case and bricks that are made of magnesia that is very much resistant to heat and it does not melt. The furnace is cooled with water that runs inside the case and bricks. The process of making is simple, from the iron ore that is basically iron oxide. Iron is made from it on the removal of oxygen. A crude iron oxide called pig iron is left over. The reduction is the process of removing oxygen where this process used carbon as this can take the ore to high temperatures.
Ore, limestone and carbon in the form of coke are put at the top of the blast furnace in the form of layers. Special types of nozzles are used which are called tuyers, these put up the air in the furnace that is at the bottom of the furnace and the process is termed as blasting. The bottom portion is filled with liquid pig iron and slag that is called hearth. This content is removed from the bottom and the process is known as skimming. Slag pot is the collector of the liquid slag. Iron can be taken from the hearth by a process called tapping. Pig iron is used in railway wagon applications.
3Fe2O3 + C → 2Fe3O4 + CO
Fe3O4 + CO → 3FeO + CO
FeO + CO → Fe + CO