Ferroalloy
Encyclopedia
Ferroalloy refers to various alloy
s of iron
with a high proportion of one or more other element
, manganese
or silicon
for example. It is used in the production of steel
s and alloys as a raw material.
The main ferroalloys are:
The leading world chromite ore-producing countries in 2008 were India (almost 4 Mt), Kazakhstan (more than 3 Mt), and South Africa (almost 10 Mt). More than 94% of chromite ore production was smelted in electric-arc furnaces to produce ferrochromium for the metallurgical industry. The leading world ferrochromium-producing countries in 2008 were China (more than 1 Mt), Kazakhstan (more than 1 Mt), and South Africa (more than 3 Mt). India and Russia each produced in excess of 0.5 Mt of ferrochromium. Most of the 7.84 Mt of ferrochromium produced worldwide was consumed in the manufacture of stainless steel which exceeded 26 Mt in 2008.
(144,000 t) and Colombia (105,000 t). Together, these three countries accounted for about 51% of world production if China is excluded. Ukraine, Indonesia, Greece,
and Macedonia, in descending order of gross weight output, all produced between 68,000 t and 90,000 t of ferronickel, accounting for an additional 31%, excluding China. China was excluded from statistics because its industry produced large tonnages of nickel pig iron
in addition to a spectrum of conventional ferronickel grades, for an estimated combined output of 590,000 t gross weight. The nickel content of individual Chinese products varied from about 1.6% to as much as 80%, depending upon customer end use.
In the United States, the steel industry accounted for virtually all the ferronickel consumed in 2008, with more than 98% used in stainless and heat-resistant steels; no ferronickel was produced in the US in 2008.
Silicon ferroalloy consumption is driven by cast iron
and steel production, where silicon alloys are used as deoxidizers. Some silicon metal was also used as an alloying agent with iron.
On the basis of silicon content, net production of ferrosilicon and miscellaneous silicon alloys in the US was 148,000 t in 2008. China is the major supplier, which in 2008 produced more ferrosilicon (4.9 Mt) than the rest of the world combined. Other major manufacturers are Norway (0.21 Mt), Russia (0.85 Mt) and US (0.23 Mt).
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
s of iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
with a high proportion of one or more other element
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
, manganese
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
or silicon
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
for example. It is used in the production of steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
s and alloys as a raw material.
The main ferroalloys are:
- FeAl – ferroaluminum
- FeB – ferroboron – 12–20% of boronBoronBoron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...
, max. 3% of siliconSiliconSilicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
, max. 2% aluminiumAluminiumAluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
, max. 1% of carbonCarbonCarbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds... - FeCe – ferroceriumFerroceriumFerrocerium is a man-made metallic material that has the ability to give off a large number of hot sparks at temperatures at when scraped against a rough surface , such as ridged steel...
- FeCr – ferrochromium
- FeMg – ferromagnesium
- FeMn – ferromanganeseFerromanganeseFerromanganese, a ferroalloy with high content of manganese, is made by heating a mixture of the oxides MnO2 and Fe2O3, with carbon, usually as coal and coke, in either a blast furnace or an electric arc furnace-type system, called a submerged arc furnace. The oxides undergo carbothermal reduction...
- FeMo – ferromolybdenumFerromolybdenumFerromolybdenum is an important iron molybdenum alloy, with a molybdenum content of 60-70% It is the main source for molybdenum alloying of HSLA steel. The molybdenum is mined and is subsequently transformed into the molybdenum oxide MoO3. This oxide is mixed with iron oxide and aluminium and is...
– min. 60% Mo, max. 1% Si, max. 0.5% Cu - FeNb – ferroniobiumFerroniobiumFerroniobium is an important iron niobium alloy, with a niobium content of 60-70%. It is the main source for niobium alloying of HSLA steel and covers more than 80% of the world wide niobium production. The niobium is mined from pyrochlore deposits and is subsequently transformed into the niobium...
, also called ferrocolumbium - FeNi – ferronickel
- FeP – ferrophosphorus
- FeSi – ferrosiliconFerrosiliconFerrosilicon, or ferrosilicium, is a ferroalloy, an alloy of iron and silicon with between 15% and 90% silicon. It contains a high proportion of iron silicides. Its melting point is about 1200 °C to 1250 °C with a boiling point of 2355 °C...
– 15–90% Si - FeSiMg – ferrosilicon magnesium (with Mg 4 to 25 %), also called nodulizer
- FeTi – ferrotitaniumFerrotitaniumFerrotitanium is a ferroalloy, an alloy of iron and titanium with between 10-20..45-75 % titanium and sometimes a small amount of carbon. It is used in steelmaking as a cleansing agent for iron and steel; the titanium is highly reactive with sulfur, carbon, oxygen, and nitrogen, forming insoluble...
– 10..30–65..75% Ti, max. 5–6.5% Al, max. 1–4% Si - FeU – ferrouraniumFerrouraniumFerrouranium, also called ferro-uranium, is a ferroalloy, an alloy of iron and uranium, after WWII usually depleted uranium. It contains about 35–50% uranium and 1.5–4% carbon....
- FeV – ferrovanadium
- FeW – ferrotungsten
Production and consumption
Ferroalloys are produced by adding chemical elements into molten metal, usually during steelmaking. They impart distinctive qualities to steel and cast iron or serve important functions during production and are, therefore, closely associated with the iron and steel industry, the leading consumer of ferroalloys. The leading ferroalloy-producing countries in 2008 were China, South Africa, Russia, Kazakhstan and Ukraine, which accounted for 77% of the world production. World production of bulk chromium, manganese and silicon ferroalloys was estimated as 29.1 million tonnes (Mt) in 2008, a 3% decrease compared with 2007.Ferrochromium
Ferromanganese
Two manganese ferroalloys, ferromanganese and silicomanganese, are key ingredients for steelmaking. China is the leading world producer of manganese ferroalloys (2.7 Mt), with output about much greater than that of the next three major producers—Brazil (0.34 Mt), South Africa (0.61 Mt) and Ukraine (0.38 Mt)—combined.Ferromolybdenum
Major producers of ferromolybdenum are Chile (16,918 t), China (40,000 t) and the United States which accounted for about 78% of world production of molybdenite ore in 2008, whereas Canada, Mexico and Peru accounted for the reamainder. Molybdenite concentrates are roasted to form molybdic oxide, which can be converted into ferromolybdenum, molybdenum chemicals, or molybdenum metal. Although the United States was the second leading molybdenum-producing country in the world in 2008, it imported more than 70% of its ferromolybdenum requirements in 2008, mostly for the steel industry (83% of ferromolybdenum consumed).Ferronickel
In 2008, the major ferronickel-producing countries were Japan (301,000 t), New CaledoniaNew Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
(144,000 t) and Colombia (105,000 t). Together, these three countries accounted for about 51% of world production if China is excluded. Ukraine, Indonesia, Greece,
and Macedonia, in descending order of gross weight output, all produced between 68,000 t and 90,000 t of ferronickel, accounting for an additional 31%, excluding China. China was excluded from statistics because its industry produced large tonnages of nickel pig iron
Nickel pig iron
Nickel pig iron is a low grade ferronickel invented in China as a cheaper alternative to pure nickel for the production of stainless steel. It is composed of low-grade nickel ore, coking coal, and a mixture of gravel and sand as an aggregate. This mixture is heated in either a blast furnace or an...
in addition to a spectrum of conventional ferronickel grades, for an estimated combined output of 590,000 t gross weight. The nickel content of individual Chinese products varied from about 1.6% to as much as 80%, depending upon customer end use.
In the United States, the steel industry accounted for virtually all the ferronickel consumed in 2008, with more than 98% used in stainless and heat-resistant steels; no ferronickel was produced in the US in 2008.
Ferrosilicon
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
and steel production, where silicon alloys are used as deoxidizers. Some silicon metal was also used as an alloying agent with iron.
On the basis of silicon content, net production of ferrosilicon and miscellaneous silicon alloys in the US was 148,000 t in 2008. China is the major supplier, which in 2008 produced more ferrosilicon (4.9 Mt) than the rest of the world combined. Other major manufacturers are Norway (0.21 Mt), Russia (0.85 Mt) and US (0.23 Mt).