Pig iron is the intermediate product of smelting iron ore with a high-carbon fuel such as coke, usually with limestone as a flux. Charcoal and anthracite have also been used as fuel. Pig iron has a very high carbon content, typically 3.5–4.5%, which makes it very brittle and not useful directly as a material except for limited applications.
The traditional shape of the molds used for these ingots was a branching structure formed in sand, with many individual ingots at right angles to a central channel or runner. Such a configuration is similar in appearance to a litter of piglets suckling on a sow. When the metal had cooled and hardened, the smaller ingots (the pigs) were simply broken from the much thinner runner (the sow), hence the name pig iron. As pig iron is intended for remelting, the uneven size of the ingots and the inclusion of small amounts of sand caused only insignificant problems considering the ease of casting and handling them.
Famous quotes containing the words pig and/or iron:
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Home again, home again, jiggety jig.
To market, to market, to buy a fine hog;
Home again, home again, joggety jog.”
—Unknown. To Market, to Market, to Buy a Fat Pig (l. 1–4)
“When Sheba was his lass,
When she the iron wrought, or
When from the smithy fire
It shuddered in the water:
Harshness of their desire
That made them stretch and yawn....”
—William Butler Yeats (1865–1939)