The main raw materials used in smelting iron are iron ore, limestone, and coke. 

Iron ore : A mineral that contains iron oxides, such as magnetite and hematite, mined iron ore is often called "crude" and the primary source of iron for the steel and iron industries.

Limestone : A calcium carbonate compound that acts as a fluxing agent and a heat source, decomposes at high temperatures in the furnace, reacting with impurities to form slag and purifies molten iron by removing impurities.

Coke: A fossil-fuel source of carbon that acts as a reducing agent . At high temperatures, the carbon in coke combines with the oxygen in the iron ore, forming carbon monoxide or carbon dioxide