Pig iron is the product of smelting iron ore (also ilmenite) with a high-carbon fuel and reductant such as coke, usually with limestone as a flux. Charcoal and anthracite are also used as fuel and reductant.
Pig iron is produced by smelting or iron ore in blast furnaces or by smelting ilmenite in electric furnaces.
The vast majority of pig iron is produced and consumed within integrated steel mill complexes. In this context the term “pig iron” is something of a misnomer: within integrated steel mills, blast furnace iron is transferred directly to the steel plant in liquid form, better known as "hot metal" or "blast furnace iron."
The term “pig iron” dates back to the time when hot metal was cast into ingots before being charged to the steel plant. The moulds were laid out in sand beds such that they could be fed from a common runner. The group of moulds resembled a litter of sucking pigs, the ingots being called “pigs” and the runner the “sow.”
Merchant pig iron is cold pig iron, cast into ingots and sold to third parties as feedstock for the steel and ferrous casting industries.
Merchant pig iron is produced by:
Merchant pig iron comprises three main types:
There are also various sub-types, for example low manganese basic pig iron, semi-nodular pig iron etc.
Pig iron contains at least 92% Fe and has a very high carbon content, typically 3.5 - 4.5%.
Other constituents are given in the table below:
Pig iron type | C | Si | Mn | S | P |
---|---|---|---|---|---|
Basic | 3.5 - 4.5 | ≤1.25 | ≤1.0 | ≤0.05 | 0.08-0.15 |
Foundry | 3.5 - 4.1 | 2.5 - 3.5 | 0.5 - 1.2 | ≤0.04 | ≤0.12 |
High Purity/Nodular | 3.7 - 4.7 | 0.05 -1.5 | ≤0.05 | ≤0.025 | ≤0.035 |
Pig iron is supplied in a variety of ingot sizes and weights, ranging from 3 kg up to more than 50 kg.
For further information about pig iron and its advantages in Electric Arc Furnace (EAF) steelmaking and ferrous casting, please see our Fact Sheets:
For the purposes of the International Maritime Organisation's International Maritime Solid Bulk Cargoes Code, the schedule for Pig Iron classifies Pig Iron as Group C (cargoes which are neither liable to liquefy nor possess chemical hazards). Please refer to our guide: Pig Iron: Guide to Transporting & Handling at Terminals