Pig iron, also known as crude iron, is the result of a high-carbon fuel smelting iron ore (also ilmenite) and a reductant such as coke, typically as a flux with limestone. Pig iron, along with silica, manganese, sulphur, phosphorus, titanium, and other dross elements, has a very high carbon content, usually, 3.8-4.7 percent, which makes it very fragile and not specifically usable as a commodity except for restricted applications. It is produced in blast furnaces by smelting or smelting of iron ore or ilmenite in electric furnaces.
The motivation behind an impact heater is to synthetically decrease and truly convert iron oxides into fluid iron called “hot metal”. The conventional state of the molds utilized for pig iron ingots was a spreading structure shaped in the sand, with numerous individual ingots at right points to a focal channel or “sprinter”, looking like a litter of piglets being nursed by a sow. Pig iron is provided in an assortment of ingot sizes and loads, running from 3 kg up to in excess of 50 kg. At the point when the metal had cooled and solidified, the littler ingots (the “pigs”) were essentially parted from the sprinter (the “sow”), subsequently the name “pig iron”.
(Pig iron obtained directly from the blast furnace and cast in molds)
A large steel stack lined with refractory brick is the blast furnace, where iron ore, coke, and limestone are poured into the top, and preheated air is blown into the bottom. It takes 6 to 8 hours for the raw materials to fall to the bottom of the furnace, where they become the final liquid slag and liquid iron component. These liquid products are drained at regular intervals from the furnace. The hot air that was blown into the base of the heater rises to the top in 6 to 8 seconds subsequent to experiencing various concoction responses. When an impact heater is begun it will consistently run for four to ten years with just short stops to perform arranged support.
The irregular scale of the ingots and the presence of small quantities of sand caused only negligible problems, given the ease of casting and handling them, as pig iron is intended for remelting. Cold pig iron, cast into ingots and sold to third parties as feedstock for the steel and ferrous casting industries, as merchant pig iron. The stage progress of the iron into the fluid in the heater was an evaded marvel, as decarburizing the pig iron into steel was a very repetitive cycle utilizing middle age innovation.
Pig Iron comprises three main types:
(Three main types of Pig Iron)
- Basic pig iron: used mainly in electric arc steelmaking
- Foundry pig iron (also known as haematite pig iron): used primarily in the production of gray iron castings in cupola furnaces
- High purity pig iron (also known as nodular pig iron): used in ductile manufacturing, also known as castings of nodular or spheroidal graphite iron.
Various sub-types are also available, such as low manganese basic pig iron, semi-modular pig iron, etc. Traditionally, in finery forges, pig iron has been worked into wrought iron, later into puddling furnaces, and more recently into steel. Pig iron is melted in these processes, and when it is stirred or agitated, a strong current of air is guided over it. This causes the broke up pollutions, (for example, silicon) to be altogether oxidized. A halfway result of puddling is known as refined pig iron, finers metal, or refined iron.
Pig iron contains at least 92% Fe and has a very high content of carbon, usually 3.5-4.5%. It is available in a range of sizes and weights, from 3 kg to more than 50 kg. For manufacturing gray iron, pig iron may also be used. This is done by remelting pig iron, sometimes along with large amounts of steel and scrap iron, removing unwanted chemicals, adding alloys, and changing the carbon content.
Some pig iron evaluations are reasonable for delivering bendable iron. These are high immaculateness pig presses and relying upon the evaluation of bendable iron being created these pig irons might be low in the components silicon, manganese, sulfur, and phosphorus. These sorts of pig iron are utilized to weaken all the components (aside from carbon) in a malleable iron charge which might be destructive to the flexible iron cycle. Until recently, pig iron was usually poured in mostly liquid form directly from the bottom of the blast furnace through a trough into a ladle car for transfer to the steel mill; in this state, the hot metal was referred to as pig iron.
Current steel processes and direct-decrease iron plants move the liquid iron to a spoon for guaranteed use in the steel making heaters or cast it into pigs on a pig-projecting machine for reuse or resale. Current pig projecting machines produce stick pigs, which break into littler 4–10 kg piglets at release.