What is "pig iron"

Iron \I"ron\ ([imac]"[u^]rn), n. [OE. iren, AS. [=i]ren, [=i]sen, [=i]sern; akin to D. ijzer, OS. [=i]sarn, OHG. [=i]sarn, [=i]san, G. eisen, Icel. [=i]sarn, j[=a]rn, Sw. & Dan. jern, and perh. to E. ice; cf. Ir. iarann, W. haiarn, Armor. houarn.]

1. (Chem.) The most common and most useful metallic element, being of almost universal occurrence, usually in the form of an oxide (as hematite, magnetite, etc.), or a hydrous oxide (as limonite, turgite, etc.). It is reduced on an enormous scale in three principal forms; viz., cast iron, steel, and wrought iron. Iron usually appears dark brown, from oxidation or impurity, but when pure, or on a fresh surface, is a gray or white metal. It is easily oxidized (rusted) by moisture, and is attacked by many corrosive agents. Symbol Fe (Latin Ferrum). Atomic number 26, atomic weight 55.847. Specific gravity, pure iron, 7.86; cast iron, 7.1. In magnetic properties, it is superior to all other substances.

   Note: The value of iron is largely due to the facility with which it can be worked. Thus, when heated it is malleable and ductile, and can be easily welded and forged at a high temperature. As cast iron, it is easily fusible; as steel, is very tough, and (when tempered) very hard and elastic. Chemically, iron is grouped with cobalt and nickel. Steel is a variety of iron containing more carbon than wrought iron, but less that cast iron. It is made either from wrought iron, by roasting in a packing of carbon (cementation) or from cast iron, by burning off the impurities in a Bessemer converter (then called Bessemer steel), or directly from the iron ore (as in the Siemens rotatory and generating furnace).

2. An instrument or utensil made of iron; -- chiefly in composition; as, a flatiron, a smoothing iron, etc.

   My young soldier, put up your iron.
   --Shak.

3. pl. Fetters; chains; handcuffs; manacles.

   Four of the sufferers were left to rot in irons.
   --Macaulay.

4. Strength; power; firmness; inflexibility; as, to rule with a rod of iron.

5. (Golf) An iron-headed club with a deep face, chiefly used in making approaches, lifting a ball over hazards, etc.

   Bar iron. See Wrought iron (below).

   Bog iron, bog ore; limonite. See Bog ore, under Bog.

   Cast iron (Metal.), an impure variety of iron, containing from three to six percent of carbon, part of which is united with a part of the iron, as a carbide, and the rest is uncombined, as graphite. It there is little free carbon, the product is white iron; if much of the carbon has separated as graphite, it is called gray iron. See also Cast iron, in the Vocabulary.

   Fire irons. See under Fire, n.

   Gray irons. See under Fire, n.

   Gray iron. See Cast iron (above).

   It irons (Naut.), said of a sailing vessel, when, in tacking, she comes up head to the wind and will not fill away on either tack.

   Magnetic iron. See Magnetite.

   Malleable iron (Metal.), iron sufficiently pure or soft to be capable of extension under the hammer; also, specif., a kind of iron produced by removing a portion of the carbon or other impurities from cast iron, rendering it less brittle, and to some extent malleable.

   Meteoric iron (Chem.), iron forming a large, and often the chief, ingredient of meteorites. It invariably contains a small amount of nickel and cobalt. Cf. Meteorite.

   Pig iron, the form in which cast iron is made at the blast furnace, being run into molds, called pigs.

   Reduced iron. See under Reduced.

   Specular iron. See Hematite.

   Too many irons in the fire, too many objects or tasks requiring the attention at once.

   White iron. See Cast iron (above).

   Wrought iron (Metal.), the purest form of iron commonly known in the arts, containing only about half of one per cent of carbon. It is made either directly from the ore, as in the Catalan forge or bloomery, or by purifying (puddling) cast iron in a reverberatory furnace or refinery. It is tough, malleable, and ductile. When formed into bars, it is called bar iron.

Pig \Pig\, n. [Cf. D. big, bigge, LG. bigge, also Dan. pige girl, Sw. piga, Icel. p[=i]ka.]

1. The young of swine, male or female; also, any swine; a hog. ``Two pigges in a poke.''
   --Chaucer.

2. (Zo["o]l.) Any wild species of the genus Sus and related genera.

3. [Cf. Sow a channel for melted iron.] An oblong mass of cast iron, lead, or other metal. See Mine pig, under Mine.

4. One who is hoggish; a greedy person. [Low]

   Masked pig. (Zo["o]l.) See under Masked.

   Pig bed (Founding), the bed of sand in which the iron from a smelting furnace is cast into pigs.

   Pig iron, cast iron in pigs, or oblong blocks or bars, as it comes from the smelting furnace. See Pig, 4.

   Pig yoke (Naut.), a nickname for a quadrant or sextant.

   A pig in a poke (that is, bag), a blind bargain; something bought or bargained for, without the quality or the value being known. [Colloq.]

1660s; see pig (n.) + iron (n.).

n. A type of crude iron shaped like a block, commonly used as an industrial raw material.

n. crude iron tapped from a blast furnace

Pig iron can refer to:

• Pig iron, an intermediate form of iron produced from iron ore and is subsequently worked into steel or wrought iron
• Pig Iron - The Album by Anti-Nowhere League
• Pig Iron Theatre Company, a theater group located in Philadelphia, PA
• Robert Menzies, an Australian Prime Minister in the 1930s was known, disparagingly, as "Pig Iron Bob"
• Peter Porkchops, a character from the DC Comics series Captain Carrot and His Amazing Zoo Crew, also known as Pig Iron

Pig iron is the intermediate product of smelting iron ore. It is the molten iron from the blast furnace, which is a large and cylinder-shaped furnace charged with iron ore, coke, and limestone. Charcoal and anthracite have also been used as fuel. Pig iron has a very high carbon content, typically 3.5–4.5%, along with silica and other constituents of dross, which makes it very brittle and not useful directly as a material except for limited applications.

The traditional shape of the molds used for pig iron ingots was a branching structure formed in sand, with many individual ingots at right angles to a central channel or runner, resembling a litter of piglets being suckled by a sow. When the metal had cooled and hardened, the smaller ingots (the pigs) were simply broken from the 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.