Iron ore refers to rocks and minerals from which metallic iron is extracted for commercial uses. This extracted iron is used for manufacturing steel which the most consumed metal globally by tonnage and purpose. Iron ore is the main ingredient in steel. Steelmaking is the process for producing steel from iron ore and scrap. It is important to note that about 98% of extracted iron ore is used for steel production.
Cycle of iron ore conversion to steel
Granulated iron ore
As you see on the above picture, first iron ore is processed into two groups: granulated iron ore and concentrate. Producing granulated iron ore is done without water (dry). In this process, iron ore, grade of 50%, is crushed in two or three levels and divided into different classes according to their size. Then high-grade iron ores are separated from low ones by physical separation methods; especially magnetic method.
Iron ore concentrate
Normally iron ore grade is low so advanced procedures are used to improve its grade and produce iron ore concentrate. This process generally includes crushing, grinding, concentration, and dewatering.
Iron ore pellets
Pelletizing is the process of converting primary ingredients and fines to a compact mass. Pellet is the final product of pelletizing and the primary material for producing raw iron and direct reduced iron (DRI). Production of DRI can be done in two ways: using gas or using coal. Countries that are rich in gas like Iran choose the first substance for resuscitation.
There are two ways to produce steel. The first one is oxygen converter process and the second one is by melting DRI and scrap. Steel which is the lighter, cheaper, and stronger form of iron ore is ideal for various purposes. It can be used in the production of vehicles, machines, appliances and etc.
Conversion factors of iron ore to steel
As you see in the above picture, the final conversion factor of iron ore to steel is 2.56. It indicates that in order to produce 1,000,000 MT of steel, we need 2,560,000 MT of iron ore.