The iron that comes out of a blast furnace, with 3.5–4.5% carbon and some silicon, manganese, phosphorus and sulphur. Most of it goes molten (as hot metal) straight to the steel plant's converter; what is cast into small ingots — pigs — and sold is merchant pig iron, a clean iron unit for electric arc furnaces and the main charge for iron foundries.
Also called
Merchant pig iron
Basic pig iron
Foundry pig iron
Nodular pig iron
High-purity pig iron
Hot metal
Pig iron ingots
AR
حديد الزهر الخام
ZH
生铁
DE
Roheisen
FR
Fonte brute
ES
Arrabio
IT
Ghisa d'altoforno
TR
Pik demir
RU
Чугун (передельный и литейный)
Main formsCast pigs (ingots), granulated pig iron; hot metal on integrated sites
Typical sizesPigs typically 3–10 kg each, with notches for breaking
Main standardsEN 10001, ISO 9147, GB/T 717, GB/T 718, GB/T 1412, GOST 805
Typical usesEAF and BOF charge, grey and ductile iron castings, rolls and ingot moulds
Overview
A blast furnace reduces iron ore with coke and melts the iron, which dissolves carbon on its way down and leaves the furnace at about 1,450–1,500 °C as hot metal with 3.5–4.5% carbon. In an integrated works nearly all of it is taken in torpedo ladles to the oxygen converter. The surplus, or the whole output of a merchant blast furnace, is poured into a pig-casting machine — a chain of iron moulds — and solidified into pigs. The name comes from the old practice of casting into sand beds, where the side channels looked like piglets suckling.
The grades differ mainly in silicon, manganese and phosphorus. Basic pig iron, for steelmaking, is low in silicon (usually below about 1%) and in phosphorus. Foundry pig iron carries more silicon, 1.5–3.5%, which makes graphite form when cast iron solidifies. Nodular or high-purity pig iron is very low in manganese, phosphorus, sulphur and trace elements such as titanium, as ductile (spheroidal-graphite) iron castings need.
Electric arc furnace plants charge basic pig iron with scrap and DRI to add carbon and clean iron, dilute residual copper and tin, and give the furnace chemical energy. Foundries melt foundry and nodular pig iron in cupolas and induction furnaces with steel scrap and returns.
Merchant pig iron is exported mainly from Brazil, Russia, Ukraine, India and South Africa. The GCC has no blast furnaces — its steel industry is built on direct reduction — so pig iron is imported by foundries and, in smaller amounts, by arc furnace plants; Iran makes it in its blast furnaces at Isfahan.
Forms & sizes
Pigs
Small ingots of about 3–10 kg, easy to handle and to charge by magnet or grab
Granulated pig iron
Hot metal granulated in water to small pieces, mainly for EAF charging
Hot metal
Liquid iron used on the integrated site; not traded
Steel Mills - Agents & Traders · Stockist - Distributor · Base Materials · Dubai
