Editing Pig iron (section)

==Uses==
Traditionally, pig iron was worked into [[wrought iron]] in [[finery forge]]s, later [[puddling furnace]]s, and more recently, into [[steel]].<ref>R. F. Tylecote, ''A history of metallurgy'' (2nd edition, Institute of Materials, London, 1992).</ref> In these processes, pig iron is melted and a strong current of air is directed over it while it is stirred or agitated. This causes the dissolved impurities (such as silicon) to be thoroughly [[Redox|oxidized]]. An intermediate product of puddling is known as ''refined pig iron'', ''finers metal'', or ''refined iron''.<ref name="em">{{cite book |last=Rajput |first=R.K. |title=Engineering Materials |publisher=S. Chand |year=2000 |pages=223 |isbn=81-219-1960-6}}</ref>

Pig iron can also be used to produce [[gray iron]]. This is achieved by remelting pig iron, often along with substantial quantities of steel and [[scrap]] iron, removing undesirable contaminants, adding alloys, and adjusting the carbon content. [[Ductile iron]] can also be produced using certain high purity grades of pig iron; depending on the grade of ductile iron being produced, the pig irons chosen may be low in the elements silicon, manganese, sulfur and phosphorus. High purity pig iron is used to dilute any elements in a ductile iron charge which may be harmful to the ductile iron process (except carbon).

=== Modern uses ===
Pig iron was historically poured directly out of the bottom of the [[blast furnace]] through a channel into a [[ladle (metallurgy)|ladle]] car for transfer to the [[steel mill]] in mostly liquid form; in this state, the pig iron was referred to as ''hot metal''. The hot metal was then poured into a [[steelmaking]] vessel to produce [[steel]], typically an [[electric arc furnace]], [[induction furnace]] or [[basic oxygen furnace]], where the excess carbon is burned off and the [[alloy]] composition controlled. Earlier processes for this included the [[finery forge]], the [[puddling furnace]], the [[Bessemer process]], and the [[open hearth furnace]].

Modern steel mills and [[direct reduced iron|direct-reduction]] iron plants transfer the molten iron to a ladle for immediate use in the steel making furnaces or cast it into pigs on a pig-casting machine for reuse or resale. Modern pig casting machines produce stick pigs, which break into smaller {{convert|4–10|kg|0|adj=on}} piglets at discharge.