Chemical reduction, or smelting, is a form of extractive metallurgy. The main use of smelting is to produce a metal from its ore. This includes iron extraction (for the production of steel) from iron ore, and copper extraction and other base metals from their ores. It makes use of a chemical reducing agent, commonly a fuel that's a source of carbon such as coke, or in earlier times charcoal, to change the oxidation state of the metal ore; however, plants for the electrolytic reduction of alumi… (More on Smelting)