From Academic Kids
- See smelt for the style of fishing with dip nets in tributaries of the Great Lakes during the spring spawning run of that small fish.
Chemical reduction or smelting is a form of extractive metallurgy. The main use of smelting is to produce iron and steel from iron ore. Smelting is also used to extract copper and other base metals from their raw ores.
It makes use of a chemical reducing agent such as carbon (coke, or in earlier times charcoal) to change the oxidation state of the metal ore. When coke is mixed with iron ore and heated, the oxygen will move from the iron to the carbon. The iron will be reduced, and the carbon will be oxidised, producing carbon dioxide and carbon monoxide. A fluxing agent such as limestone is used to remove the accompanying rock gangue as slag (also called scoria or cinder).
In Ancient Egypt somewhere between the Third Intermediate Period and 23rd Dynasty (1100 BC - 750 BC) there are indications of iron working. There are further indications of iron smelting and working in West Africa in 500 BC  (http://www.louisville.edu/a-s/history/herlin/textsup.htm). The process of smelting became widely used during the Industrial Revolution, when it was used extensively in the production of iron and steel.