Råjernet

Råjernet, or råjärnet in Swedish and Norwegian, is the term for pig iron, a crude form of iron produced by smelting iron ore with coke in a blast furnace. It contains a relatively high carbon content (about 3–4.5%) and various impurities such as silicon, sulfur, and phosphorus, as well as slag. The carbon and impurities make råjernet hard and brittle, unsuitable for most direct applications.

Production: In a blast furnace, iron ore, coke, and limestone are charged from the top. Chemical reactions remove oxygen from the ore, producing molten iron that collects at the bottom, along with slag. The liquid metal is tapped and directed into sand molds or into runners forming multiple ingots, historically described as a bed of pigs, giving rise to the name pig iron.

Characteristics and processing: Raw råjernet has to be refined to produce steel or wrought iron. Through processes such as decarburization, basic oxygen steelmaking, or electric arc furnace melting, carbon content is reduced and impurities removed. In some cases, råjernet is further cast directly into a variety of cast iron products, but generally it serves as feedstock for steelmaking.

History and use: Råjernet has been produced since ancient times as an intermediate in iron and steel production. The term remains common in Scandinavian languages as the name for crude iron prior to refining. Today, most råjernet is remelted or refined in integrated steelworks or foundries.