Stone age began approximately 2,198,000 BCE
The kiln is lined with stones and clay the sulfide ore is added. Then the air is blown into it from goatskin bellows or people. The by product (slag) is removed an copper solidifies at the base of the kiln.
It is stronger than copper but has a lower melting point improving malleability
calcination is when the iron ore is heated in the absences of air causing carbonates to turn into oxides. Smelting refers to the heating at higher temperatures in a blast furnace
Steel is an alloy and made up of iron, carbon and other metals
Aluminium is extracted from the ground in compounds, it is the purified to aluminium oxide in the bayer process(this is a process of refining bauxite to form Aluminium oxide) and then it undergoes electrolysis in a cryolite solution to form aluminium