Products Copper Copper is one of the basic non-ferrous metals, which plays important role in history from ancient times and especially in modern economy as the main metal for electric conductors. Coal Coal was the main source of energy for Industrial revolution and today it still plays important role in world energy balance providing 29% of world primary energy use. Zinc Zinc is the main metal for protecting steel against corrosion by galvanizing Precious metals (gold, silver) Precious metals such as gold and silver along with copper used by humanity from ancient times.