Ferrovanadium (FeV) is an alloy formed by combining

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

and

vanadium Vanadium is a chemical element; it has Symbol (chemistry), symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an ...

with a vanadium content range of 35–85%. The production of this alloy results in a grayish silver

crystalline solid A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macrosc ...

that can be crushed into a powder called "ferrovanadium dust".Hathaway, G. J.; Proctor, N. H. ''Proctor and Hughes chemical hazards of the workplace''; Wiley-Interscience: Hoboken, 2004. Ferrovanadium is a universal hardener, strengthener and anti-corrosive additive for

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

s like

high-strength low-alloy steel High-strength low-alloy steel (HSLA) is a type of alloy steel that provides better mechanical properties or greater resistance to corrosion than carbon steel. HSLA steels vary from other steels in that they are not made to meet a specific chemica ...

tool steel Tool steel is any of various carbon steels and alloy steels that are particularly well-suited to be made into tools and tooling, including cutting tools, dies, hand tools, knives, and others. Their suitability comes from their distinctive ...

s, 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 In chemistry, iron(II) refers to the element iron in its +2 oxidation state. The adjective ''ferrous'' or the prefix ''ferro-'' is often used to specify such compounds, as in ''ferrous chloride'' for iron(II) chloride (). The adjective ''ferr ...

. One such use is to improve

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...

resistance to

alkaline In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The ...

reagents In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...

as well as

sulfuric Sulfur (American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form ...

and

hydrochloric acid Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

s. It is also used to improve the

tensile strength Ultimate tensile strength (also called UTS, tensile strength, TS, ultimate strength or F_\text in notation) is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials, the ultimate ...

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),

screwdriver A screwdriver is a tool, manual or powered, used for turning screws. Description A typical simple screwdriver has a handle and a shaft, ending in a tip the user puts into the screw head before turning the handle. This form of the screwdriver ...

ratchet Ratchet may refer to: Devices * Ratchet (device), a mechanical device that allows movement in only one direction * Ratchet effect in sociology and economics * Ratchet, metonymic name for a socket wrench incorporating a ratcheting device * Ratc ...

s, etc.

Composition

Vanadium content in ferrovanadium ranges from 35% to 85%. FeV80 (80% Vanadium) is the most common ferrovanadium composition.Swinbourne, D. R.; Richardson, T.; Cabalteja, F. Understanding ferrovanadium smelting through computational thermodynamics modeling. ''Mineral Processing and Extractive Metallurgy'' 2016, 125 (1), 45–55. In addition to iron and vanadium, small amounts of

silicon Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid (sometimes considered a non-metal) and semiconductor. It is a membe ...

aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

arsenic Arsenic is a chemical element; it has Symbol (chemistry), symbol As and atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is not ...

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

, and

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

are found in ferrovanadium.

Impurities In chemistry and materials science, impurities are chemical substances inside a confined amount of liquid, gas, or solid. They differ from the chemical composition of the material or compound. Firstly, a pure chemical should appear in at least on ...

can make up to 11% by weight of the alloy. Concentrations of these impurities determine the grade of ferrovanadium.Gasik, M. ''Handbook of Ferroalloys: Theory and Technology''; Butterworth-Heinemann Ltd: s.l., 2013.

Synthesis

Eighty-five percent of all vanadium extracted from the Earth is used to create alloys such as ferrovanadium. There are two common ways in which ferrovanadium is produced: silicon reduction and aluminum reduction.

Reduction by silicon

Vanadium pentoxide Vanadium(V) oxide (''vanadia'') is the inorganic compound with the formula V2 O5. Commonly known as vanadium pentoxide, it is a dark yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of ...

(V₂O₅),

ferrosilicon Ferrosilicon is an ferroalloy, alloy of iron and silicon. It has a typical silicon content of 15–90% by weight and a high proportion of iron silicides. Production and reactions Ferrosilicon is produced by reduction of silica or sand with coke ...

(FeSi75), lime (CaO) and

slag The general term slag may be a by-product or co-product of smelting (pyrometallurgical) ores and recycled metals depending on the type of material being produced. Slag is mainly a mixture of metal oxides and silicon dioxide. Broadly, it can be c ...

(recycled vanadium containing waste) and are combined in an

electric arc furnace An electric arc furnace (EAF) is a Industrial furnace, furnace that heats material by means of an electric arc. Industrial arc furnaces range in size from small units of approximately one-tonne capacity (used in foundry, foundries for producin ...

heated to 1850 °C.Vermaak , M. K. G. Vanadium recovery in the electro-aluminothermic production of ferrovanadium. thesis, 2000 Silicon in the ferrosilicon reduces the vanadium in V₂O₅ to vanadium metal. The vanadium then interacts with the iron to form ferrovanadium. Excess lime and V₂O₅ are added to use up the silicon and refine the metal. This process produces vanadium concentrations between thirty-five and sixty percent. 2 V₂O₅ + 5 (Fe_y/5Si)_alloy + 10 CaO → 4 (Fe_y/4V)_alloy + 5 Ca₂SiO₄

Reduction by Aluminum

Iron, V₂O₅, aluminum, and lime are combined in an electric arc furnace. Like the silicon, aluminum reduces the vanadium in V₂O₅ to vanadium metal. The vanadium dissolves into the iron and forms the ferrovanadium alloy. Sutulov, A.; Wang, C. T. Vanadium processing https://www.britannica.com/technology/vanadium-processing#ref82021 (accessed Mar 22, 2018). The resulting ferrovanadium has a vanadium concentration between seventy and eighty-five percent. 3 V₂O₅ + 10 Al → 6 V + 5 Al₂O₃ V_x + Fe_1−x → (Fe_1−xV_x)_alloy

Toxicology

Ferrovanadium dust is a mild irritant that affects the

eyes An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

when touched by contaminated

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

and the

respiratory tract The respiratory tract is the subdivision of the respiratory system involved with the process of conducting air to the alveoli for the purposes of gas exchange in mammals. The respiratory tract is lined with respiratory epithelium as respirato ...

when inhaled. The dust caused

chronic bronchitis Bronchitis is inflammation of the bronchi (large and medium-sized airways) in the lungs that causes coughing. Bronchitis usually begins as an infection in the nose, ears, throat, or sinuses. The infection then makes its way down to the bronchi. ...

and

pneumonitis Pneumonitis describes general inflammation of lung tissue. Possible causative agents include radiation therapy of the chest, exposure to medications used during chemo-therapy, the inhalation of debris (e.g., animal dander), aspiration, herbicide ...

in animals exposed to high concentration (1000–2000 mg/m³) at intervals for two months. However, no such long-term effects have been observed in humans.

Occupational exposure

The

American Conference of Governmental Industrial Hygienists The American Conference of Governmental Industrial Hygienists (ACGIH) is a professional association of industrial hygienists and practitioners of related professions, with headquarters in Cincinnati, Ohio. One of its goals is to advance worker pr ...

(ACGIH) states that an employee who is working eight hours a day, five days a week, can be exposed to ferrovanadium dust in their place of work at concentrations of up to 1.0 mg/m³ without adverse effects. Short-term exposures should be kept below 3.0 mg/m³. It is suggested that those working with high concentrations of ferrovanadium dust wear a

respirator A respirator is a device designed to protect the wearer from inhaling hazardous atmospheres including lead, lead fumes, vapors, gases and particulate matter such as dusts and airborne pathogens such as viruses. There are two main categories o ...

to prevent

inhalation Inhalation (or inspiration) happens when air or other gases enter the lungs. Inhalation of air Inhalation of air, as part of the cycle of breathing, is a vital process for all human life. The process is autonomic (though there are exceptions ...

and irritation of the respiratory tract.

Steel

The most common use of ferrovanadium is in the production of steel. In 2017, 94% of consumption of vanadium in the USA was to produce iron and

steel alloys Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

.U.S. Geological Survey; Vanadium. ''Mineral commodity summaries 2018: U.S. Geological Survey'' 2018, 180-181. Ferrovanadium and other vanadium alloys are used in carbon steel, alloy steel, high strength steel, and HSLA (High Strength Low Alloy) steel. These steels are then used to make automotive parts,

pipes Pipe(s), PIPE(S) or piping may refer to: Objects * Pipe (fluid conveyance), a hollow cylinder following certain dimension rules ** Piping, the use of pipes in industry * Smoking pipe ** Tobacco pipe * Half-pipe and quarter pipe, semi-circu ...

tools A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates ...

, and more. The addition of ferrovanadium toughens the steel making it more resistant to temperature and torsion. This increase in strength is a result of the formation of vanadium carbides which have a rigid crystal structure as well as a finer grain size which decreases the

ductility Ductility refers to the ability of a material to sustain significant plastic Deformation (engineering), deformation before fracture. Plastic deformation is the permanent distortion of a material under applied stress, as opposed to elastic def ...

of the steel. In addition to adding to the composition of the steel, ferrovanadium can also be used as a coating on the steel. When coated with nitrated ferrovanadium, the abrasion resistance of steel increases 30-50%.

Market

Between 2013 and 2017, the United States imported 13,510 tons of ferrovanadium, a majority of which came from Czechia, Austria, Canada, and South Korea. The price of ferrovanadium has fluctuated dramatically since 1996, hitting an all-time high in 2008 at $76041.61/ton FeV80.Bumbac, C. ''Journal of Global Economics'' 2011, ''3'' (3), 30–41. In more recent years, it has once again seen an increase in price as

environmental standards Environment most often refers to: __NOTOC__ * Natural environment, referring respectively to all living and non-living things occurring naturally and the physical and biological factors along with their chemical interactions that affect an organism ...

shut down some of the vanadium producers in China. These shutdowns, as well as the closure of a South African vanadium mine, created a vanadium shortage, forcing ferrovanadium factories to reduce their production of ferrovanadium, decreasing its supply and driving up the price.

References

{{reflist Vanadium compounds Ferrous alloys