Metal smelting is the process of creating metal by heating metal ore. The ore, be it iron, copper or tin, is mixed with a carbon and the mixture is heated to the point of conversion into a liquid form. The liquid is then mixed with a flux, such as limestone, when metal smelting. The flux allows all of the impurities formed while metal smelting to be removed from the top of the liquid as slag. The remaining liquid metal is super-heated to remove the oxygen molecules and the remaining liquid is poured into molds or dies and allowed to cool.
The process of metal smelting begins by mining the ore from the earth. There are several types of ore used in metal smelting, with the particular ore corresponding to the type of metal that is being smelted. In the case of iron ore, iron will be the end result. Once the ore has been mined, it is placed in a container and mixed with another chemical, such as carbon, when smelting iron. In most cases, coke, a byproduct of coal, is used in the production of iron.
Once the ore and the coke are combined, the next step in metal smelting is to heat the two chemicals until a liquid forms. Once the heated chemicals are turned to liquid, another chemical, flux, is added to allow the impurities of the liquid to be removed. This chemical is commonly limestone. By adding the flux or limestone to the mixture, the impurities in the liquid rise to the top and form a slag. The slag is removed by skimming it off of the top of the liquid and discarding it. Once all the slag has been removed from the liquid, the mixture is reduced by super-heating the materials.
The reduction stage in metal smelting is comprised of super-heating the liquid chemicals to remove any oxygen molecules that might be left in the mixture. This reduction is accomplished by introducing carbon monoxide into the furnace. The resulting liquid is the elemental metal in the form of iron, tin or any other type of ore that is being used. The liquid is poured into molds and allowed to cool and solidify into the final product, metal. The amount of heat required for the reduction phase to occur varies greatly by the type of ore that is being smelted and the melting point of the particular base metal.