What is the blast furnace ironmaking?

Blast furnace ironmaking is a traditional ironmaking method based on coke energy. It cooperates with converter steelmaking and is the main method of producing steel at present. This dominance of blast furnace ironmaking is not expected to change for quite a long time. The essence of blast furnace ironmaking is the reduction of iron, that is, coke is used as fuel and reducing agent. At high temperature, iron ore or iron-containing raw materials are changed from oxide or mineral state (such as Fe2O3, Fe3O4, Fe2SiO4) reduced to liquid pig iron.

In the smelting process, the charge (ore, flux, coke) is charged into the furnace in batches from the top of the furnace through the charging equipment according to a determined ratio. The high-temperature hot air blown in from the lower tuyere reacts with coke, and the generated high-temperature reducing gas rises, causing the charge to heat, reduce, melt, and make slag, resulting in a series of physical and chemical changes. Finally, liquid slag and iron are collected in the furnace. Cylinders are periodically discharged from the blast furnace. During the rising process, the temperature of the gas stream is continuously reduced, the composition gradually changes, and finally the blast furnace gas is formed and discharged from the furnace roof.