Ferroalloy

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Ferroalloy refers to various alloys of iron with a high proportion of one or more other elements such as manganese (Mn), aluminium (Al), or silicon (Si). [1] They are used in the production of steels and alloys. [2] [3] The alloys 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 producers of ferroalloys in 2014 were China, South Africa, India, Russia and Kazakhstan, which accounted for 84% of the world production. [4] World production of ferroalloys was estimated as 52.8 million tonnes in 2015. [5]

Contents

Compounds

The main ferroalloys are:


Production, by processes

Evolution of the global ferroalloys production, by processes. Ferroalloys production evolution.svg
Evolution of the global ferroalloys production, by processes.

Ferroalloys are produced generally by two methods : in a blast furnace or in an electric arc furnace. Blast furnace production continuously decreased during the 20th century, whereas the electric arc production is still increasing. Today, ferromanganese can be still efficiently produced in a blast furnace, but, even in this case, electric arc furnace are spreading. More commonly, ferroalloys are produced by carbothermic reactions, involving reduction of oxides with carbon (as coke) in the presence of iron. Some ferroalloys are produced by the addition of elements into molten iron.

It is also possible to produce some ferroalloys by direct reduction processes. For example, the Krupp-Renn Process is used in Japan to produce ferronickel. [6]

Production and consumption, by ferroalloys

Ferrochromium Ferrochrome.JPG
Ferrochromium

Ferrochromium

The leading world chromite ore-producing countries in 2014 were South Africa (12 Mt), Kazakhstan (3.7 Mt), India (3.5 Mt), and Turkey (2.6 Mt). Most of the chromite ore production was smelted in electric-arc furnaces to produce ferrochromium for the metallurgical industry. The leading world ferrochromium-producing countries in 2014 were China (4.5 Mt), South Africa (3.6 Mt), Kazakhstan (1.2 Mt) and India (0.9 Mt). Most of the 11.7 Mt of ferrochromium produced worldwide was consumed in the manufacture of stainless steel which totalled 41.7 Mt in 2014. [4]

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 much larger than the combined output of the next three biggest producers—Brazil (0.34 Mt), South Africa (0.61 Mt) and Ukraine (0.38 Mt). [2]

Ferromolybdenum

Major producers of ferromolybdenum are Chile (16,918 t), China (40,000 t) and the United States (which, in 2008, accounted for 78% of world molybdenite ore production. Canada, Mexico and Peru accounted for the remainder. 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). [2]

Ferronickel

Characteristics,
17–24% Ni [7]
Density3.8 g/cm3
Melting point1500°C
Boiling point2900°C

In 2014, about 33% of the world’s annual new nickel was ferronickel, [8] an extensive review article of which was published by Swartzendruber et al in 1991. [9] Many of the meteorites that fall to Earth turn out to be ferronickel, [9] and take the form of kamacite and/or taenite.[ citation needed ] Ferronickel has a face-centred cubic crystal structure (via Ni). [10] It can take the form of ferrite, martensite, or austenite. The binary Fe-Ni system has been investigated for analogic purposes to steel because the presence of nickel in high-alloy steels such as austenitic stainless steels and maraging steels is a key driver for the transition from body-centered cubic ferrite to face-centered cubic austenite. [11]

In the late 20th century, 60% of nickel production was based on the matte smelting of sulfide ores, this did not lend itself to ferronickel production. [12] According to 2003 data, the share of laterites in primary nickel production was reported to be 42%. [12] World annual production of ferronickel in 2014 was around 250,000 tonnes. [8] The two largest producers were BHP and Société Le Nickel. [8] Laterite ores are often used to supply the production process. [13] [14] The RKEF process is often used. [15] The energy consumption per tonne of product is high for laterite ores because of the low-grade feed, and hence produces a lot of waste slag and gaseous pollution. [16] Generally, over 90% of the furnace output is in the form of slag. [8] The technique of refining molten ferronickel is a topic for specialists, [17] and because of ore content variability the processes might even need to be tailored by source: for example the Larco process of Greek ores. [18] "The main reason for adding nickel in ferrous alloys is to promote an austenitic microstructure. Nickel generally increases ductility, toughness and corrosion resistance." [19] Nickel pig iron is distinguished from ferronickel by the former's low weight fraction (4–10%) of nickel and high carbon content (>3%). In contrast, ferronickel is a relatively pure binary alloy. [19]

In 2008, the major ferronickel-producing countries were Japan (301,000 t), New Caledonia (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. [2]

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. [2]

The nickel pig iron is a low grade ferronickel made in China, which is very popular since the 2010s.

Ferrosilicon

Ferrosilicon Ferrosilicon.JPG
Ferrosilicon

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). [2]

Ferrotitanium

Titanium is used in steelmaking for deoxidation, grain-size control, and carbon and nitrogen control and stabilization. During steelmaking, titanium is usually introduced as ferrotitanium because of its relatively low melting temperature and high density. Steels with relatively high titanium content include interstitial-free, stainless and high-strength low-alloy steels. Ferrotitanium is usually produced by induction melting of titanium scrap with iron or steel; however, it also is produced directly from titanium mineral concentrates. The standard grades of ferrotitanium are 30% and 70% titanium. Ferrosilicon-titanium also is produced to allow the simultaneous addition of silicon and titanium. The leading ferrotitanium producing countries include Brazil, China, India, Japan, Russia, Ukraine, United Kingdom and the United States. [2]

Ferrotantalum

Ferrotantalum is added to molten steel to create hardenable specialty steels. It is also used as welding material, spraying powder, and for powder metallurgy applications. [20]

Ferrotungsten

Tungsten is an important alloying element in high-speed and other tool steels, and is used to a lesser extent in some stainless and structural steels. Tungsten is often added to steel melts as ferrotungsten, which can contain up to 80% tungsten. World ferrotungsten production is dominated by China, which in 2008 exported 4,835 t (gross weight) of the alloy. Ferrotungsten is relatively expensive, with the prices around $31–44 per kilogram of contained tungsten. [2]

Ferrovanadium

Ferrovanadium chunks FerroVanadium.jpg
Ferrovanadium chunks

In 2008, China, Russia (12,000 t) and South Africa (17,000 t) accounted for 98% of world vanadium mine production. In these three countries, vanadium was primarily recovered from titanium-bearing magnetite ore processed to produce pig iron. The process entails aluminothermic reduction of vanadium(V) oxide, aluminium (as oxide getter), and scrap iron. [1] This produces a slag containing 20% to 24% vanadium pentoxide, which can be further processed to ferrovanadium containing 40% to 50% vanadium. Of the 5,090 t of vanadium consumed in the United States in 2008, 84% came from ferrovanadium and nearly all of it (99%) went into steel manufacturing. [2]

Related Research Articles

<span class="mw-page-title-main">Alloy</span> Mixture or metallic solid solution composed of two or more elements

An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, opacity, and luster, but may have properties that differ from those of the pure metals, such as increased strength or hardness. In some cases, an alloy may reduce the overall cost of the material while preserving important properties. In other cases, the mixture imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength.

<span class="mw-page-title-main">Metallurgy</span> Field of science that studies the physical and chemical behavior of metals

Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys.

<span class="mw-page-title-main">Steel</span> Metal alloy of iron with other elements

Steel is an alloy of iron and carbon with improved strength and fracture resistance compared to other forms of iron. Because of its high tensile strength and low cost, steel is one of the most commonly manufactured materials in the world. Steel is used in buildings, as concrete reinforcing rods, in bridges, infrastructure, tools, ships, trains, cars, bicycles, machines, electrical appliances, furniture, and weapons.

<span class="mw-page-title-main">Iron ore</span> Ore rich in iron or the element Fe

Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the form of magnetite (Fe
3O
4, 72.4% Fe), hematite (Fe
2O
3, 69.9% Fe), goethite (FeO(OH), 62.9% Fe), limonite (FeO(OH)·n(H2O), 55% Fe), or siderite (FeCO3, 48.2% Fe).

<span class="mw-page-title-main">Ilmenite</span> Titanium-iron oxide mineral

Ilmenite is a titanium-iron oxide mineral with the idealized formula FeTiO
3. It is a weakly magnetic black or steel-gray solid. Ilmenite is the most important ore of titanium and the main source of titanium dioxide, which is used in paints, printing inks, fabrics, plastics, paper, sunscreen, food and cosmetics.

<span class="mw-page-title-main">Slag</span> By-product of smelting ores and used metals

Slag is a by-product of smelting (pyrometallurgical) ores and recycled metals. Slag is mainly a mixture of metal oxides and silicon dioxide. Broadly, it can be classified as ferrous, ferroalloy or non-ferrous/base metals. Within these general categories, slags can be further categorized by their precursor and processing conditions. "Slag generated from the EAF process can contain toxic metals, which can be hazardous to human and environmental health".

<span class="mw-page-title-main">Industrial processes</span> Process of producing goods

Industrial processes are procedures involving chemical, physical, electrical, or mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy industry.

<span class="mw-page-title-main">Ferrochrome</span> Alloy of chromium and iron

Ferrochrome or ferrochromium (FeCr) is a type of ferroalloy, that is, an alloy of chromium and iron, generally containing 50 to 70% chromium by weight.

<span class="mw-page-title-main">Ferrovanadium</span> Alloy of iron and vanadium

Ferrovanadium (FeV) is an alloy formed by combining iron and vanadium with a vanadium content range of 35–85%. The production of this alloy results in a grayish silver crystalline solid that can be crushed into a powder called "ferrovanadium dust". Ferrovanadium is a universal hardener, strengthener and anti-corrosive additive for steels like high-strength low-alloy steel, tool steels, as well as other ferrous-based products. It has significant advantages over both iron and vanadium individually. Ferrovanadium is used as an additive to improve the qualities of ferrous alloys. One such use is to improve corrosion resistance to alkaline reagents as well as sulfuric and hydrochloric acids. It is also used to improve the tensile strength to weight ratio of the material. One application of such steels is in the chemical processing industry for high pressure high throughput fluid handling systems dealing with industrial scale sulfuric acid production. It is also commonly used for hand tools e.g. spanners (wrenches), screwdrivers, ratchets, etc.

<span class="mw-page-title-main">Ferrosilicon</span> Alloy of silicon and iron

Ferrosilicon is an alloy of iron and silicon with a typical silicon content by weight of 15–90%. It contains a high proportion of iron silicides.

<span class="mw-page-title-main">Electrometallurgy</span>

Electrometallurgy is a method in metallurgy that uses electrical energy to produce metals by electrolysis. It is usually the last stage in metal production and is therefore preceded by pyrometallurgical or hydrometallurgical operations. The electrolysis can be done on a molten metal oxide which is used for example to produce aluminium from aluminium oxide via the Hall-Hérault process. Electrolysis can be used as a final refining stage in pyrometallurgical metal production (electrorefining) and it is also used for reduction of a metal from an aqueous metal salt solution produced by hydrometallurgy (electrowinning).

<span class="mw-page-title-main">Ferro Alloys Corporation</span>

The Ferro Alloys Corporation Limited (FACOR) was floated in 1955 by the house of Sarafs and Mors to become the first major producer of ferromanganese in India.

Deoxidization is a method used in metallurgy to remove the oxygen content during steel manufacturing. In contrast, antioxidants are used for stabilization, such as in the storage of food. Deoxidation is important in the steelmaking process as oxygen is often detrimental to the quality of steel produced. Deoxidization is mainly achieved by adding a separate chemical species to neutralize the effects of oxygen or by directly removing the oxygen.

<span class="mw-page-title-main">Cobalt extraction</span>

Cobalt extraction refers to the techniques used to extract cobalt from its ores and other compound ores. Several methods exist for the separation of cobalt from copper and nickel. They depend on the concentration of cobalt and the exact composition of the ore used.

In 2022, the United States was the world’s third-largest producer of raw steel, and the sixth-largest producer of pig iron. The industry produced 29 million metric tons of pig iron and 88 million tons of steel. Most iron and steel in the United States is now made from iron and steel scrap, rather than iron ore. The United States is also a major importer of iron and steel, as well as iron and steel products.

<span class="mw-page-title-main">Stakhanov Ferroalloy Plant</span>

Stakhanov Ferroalloy Plant is the largest plant for the production of ferrosilicon in Ukraine. The plant is located in the city of Kadiivka, Luhansk Oblast, Ukraine. It is located on uncontrolled territory.

Direct reduction is the fraction of iron oxide reduction that occurs in a blast furnace due to the presence of coke carbon, while the remainder - indirect reduction - consists mainly of carbon monoxide from coke combustion.

<span class="mw-page-title-main">Krupp–Renn Process</span> A direct reduction steelmaking process used from the 1930s to the 1970s.

The Krupp–Renn process was a direct reduction steelmaking process used from the 1930s to the 1970s. It used a rotary furnace and was one of the few technically and commercially successful direct reduction processes in the world, acting as an alternative to blast furnaces due to their coke consumption. The Krupp-Renn process consumed mainly hard coal and had the unique characteristic of partially melting the charge. This method is beneficial for processing low-quality or non-melting ores, as their waste material forms a protective layer that can be easily separated from the iron. It generates Luppen, nodules of pre-reduced iron ore, which can be easily melted down.

References

PD-icon.svg This article incorporates public domain material from Ferroalloys (PDF). United States Geological Survey.

  1. 1 2 Rudolf Fichte. "Ferroalloys". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a10_305. ISBN   978-3527306732.
  2. 1 2 3 4 5 6 7 8 9 Corathers, Lisa A.; et al. (October 2010). Ferroalloys (PDF). Minerals Yearbook 2008 (Report). Vol. I. U.S. Geological Survey. pp. 25.1–25.14. doi: 10.3133/mybvi . Retrieved 2019-10-18.
  3. ↑ Moskalyk, R. R.; Alfantazi, A. M. (2003). "Processing of vanadium: a review". Minerals Engineering. 16 (9, September 2003): 793–805. doi:10.1016/S0892-6875(03)00213-9.
  4. 1 2 Bedinger, George M.; Corathers, Lisa A.; et al. (October 2016). Ferroalloys (PDF). Minerals Yearbook 2014 (Report). Vol. I. U.S. Geological Survey. pp. 25.1–25.3. doi: 10.3133/mybvi . Retrieved 2019-10-18.
  5. ↑ Singerling, Sheryl A.; Tuck, Christopher A.; et al. (June 2018). Ferroalloys (PDF). Minerals Yearbook 2015 (Report). Vol. I. U.S. Geological Survey. pp. 25.1–25.14. doi: 10.3133/mybvi . Retrieved 2019-10-18.
  6. ↑ Kudo, Akira. Japanese-German Business Relations: Co-operation and Rivalry in the Interwar. pp. 89–108. Archived from the original on 2014-10-20. Retrieved 2014-12-21.
  7. ↑ "Ferronickel – Properties, Applications". AZoM.com. August 21, 2013.
  8. 1 2 3 4 Swinbourne, Douglas R. "Modelling of Nickel Laterite Smelting to Ferronickel" (PDF). High Temperature Processing Symposium 2014. Swinburne University of Technology.
  9. 1 2 Swartzendruber, L. J.; Itkin, V. P.; Alcock, C. B. (1991). "The Fe-Ni (iron-nickel) system". Journal of Phase Equilibria. 12 (3): 288–312. doi:10.1007/BF02649918. S2CID   198915324.
  10. ↑ Tatsuya Tokunaga; Hiroshi Ohtani; Mitsuhiro Hasebe (2005). "Thermodynamic Study of Phase Equilibria in the Ni–Fe–B System". Materials Transactions. 46 (6): 1193–1198. doi: 10.2320/matertrans.46.1193 .{{cite journal}}: CS1 maint: date and year (link)
  11. ↑ Nakada, Nobuo; Kusunoki, Naoki; Kajihara, Masanori; Hamada, Junichi (2017). "Difference in thermodynamics between ferrite and martensite in the Fe-Ni system". Scripta Materialia. 138: 105–108. doi: 10.1016/j.scriptamat.2017.05.050 .
  12. 1 2 Keskinkilic, Ender (2019). "Nickel Laterite Smelting Processes and Some Examples of Recent Possible Modifications to the Conventional Route". Metals. 9 (9): 974. doi: 10.3390/met9090974 .
  13. ↑ Crundwell, Frank K.; Moats, Michael S.; Ramachandran, Venkoba; Robinson, Timothy G.; Davenport, William G. (2011). "Upgrading of Laterite Ores". Extractive Metallurgy of Nickel, Cobalt and Platinum Group Metals. pp. 39–47. doi:10.1016/B978-0-08-096809-4.10003-6. ISBN   9780080968094.
  14. ↑ Polyakov, Oleg (2013). "Technology of Ferronickel". Handbook of Ferroalloys. pp. 367–375. doi:10.1016/B978-0-08-097753-9.00010-1. ISBN   9780080977539.
  15. ↑ "Production of FeNi from high iron nickel ores" Svana, Erik and Ysteb, Roald (1983) Production of FeNi from high iron nickel ores. In: Proceedings of the Seminar on Problems and Prospects of Ferro-Alloy Industry in India, Oct. 24–26, 1983, NML, Jamshedpur.
  16. ↑ Swinbourne, D. R. (2014). "Understanding ferronickel smelting from laterites through computational thermodynamics modelling". Mineral Processing and Extractive Metallurgy. 123 (3): 127–140. doi:10.1179/1743285514Y.0000000056. S2CID   136838900.
  17. ↑ Crundwell, Frank K.; Moats, Michael S.; Ramachandran, Venkoba; Robinson, Timothy G.; Davenport, William G. (2011). "Refining Molten Ferronickel". Extractive Metallurgy of Nickel, Cobalt and Platinum Group Metals. pp. 85–93. doi:10.1016/B978-0-08-096809-4.10007-3. ISBN   9780080968094.
  18. ↑ Zevgolis, Emmanouil. (2004). The evolution of the Greek ferronickel production process. International Laterite Nickel Symposium. 619–632.
  19. 1 2 "Nickel metal vs. Ferronickel for the production of ferrous alloys". Metals Hub GmbH.
  20. ↑ "FA1679 Ferro Tantalum (FeTa) Alloy". Refractory Metals and Alloys. Retrieved 2022-12-05.
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