What happens in a steel furnace?
Basically, the blast furnace is a countercurrent heat and oxygen exchanger in which rising combustion… Coke is ignited at the bottom and burned rapidly with the forced air from the tuyeres. The iron oxides in the ore are chemically reduced to molten iron by carbon and carbon monoxide from the coke.
Why Coke is used in blast furnace?
Blast furnace ironmaking makes use of coke as the major source for both energy and reduction of iron oxides. In the blast furnace process, coke has multifunctions and plays an important role as reductant, burden support, and fuel.
Why limestone is used in blast furnace?
Limestone is also used to remove impurities from the blast furnace when making iron. The impurities are mostly silicon dioxide (also known as sand). The calcium carbonate in the limestone reacts with the silicon dioxide to form calcium silicate (also known as slag).
What is limestone used for today?
Limestone has numerous uses: as a building material, an essential component of concrete (Portland cement), as aggregate for the base of roads, as white pigment or filler in products such as toothpaste or paints, as a chemical feedstock for the production of lime, as a soil conditioner, and as a popular decorative …
Why is limestone added to steel?
Limestone and lime are used to make iron ore pellets. An alternative raw material for the blast furnace is iron ore sinter. Limestone and lime added to the sinter react with impurities and balance the slag composition of pig iron production.
What is limestone chemical formula?
Limestone consists of calcium carbonate, which has the chemical formula CaCO3. Limestone exists in sedimentary and crystalline form.
What is silicon in steel?
Silicon. Silicon is perhaps the most common alloying element in steel, as almost all steel requires silicon during the manufacturing process. Silicon helps to purify the iron ore during the smelting process by deoxidizing it and removing other impurities from it.
What is the purpose of silicon in steel?
Silicon is present in Alloyed High Strength Steels (AHSS) to improve their mechanical and corrosion resistance, as well as in electrical steels for improving the electrical resistivity, which is an important property for applications as the core material of electro-magnetic devices such as motors [4], [5], [6].
Why is Sulphur used in steel?
Sulphur improves machinability but lowers transverse ductility and notched impact toughness and has little effects on the longitudinal mechanical properties. Free cutting steels have sulphur added to improve machinability, usually up to a maximum of 0.35%.