DEFINITION
Vanadium located in the fourth period of group V of the secondary (B) subgroup of the Periodic table.
Refers to elements of the d-family. Metal. Designation - V. Serial number - 23. Relative atomic mass - 50.941 amu.
Electronic structure of the vanadium atom
The vanadium atom consists of a positively charged nucleus (+23), inside of which there are 23 protons and 28 neutrons, and 23 electrons move around in four orbits.
Fig.1. Schematic structure of the vanadium atom.
The distribution of electrons among orbitals is as follows:
1s 2 2s 2 2p 6 3s 2 3p 6 3d 3 4s 2 .
The outer energy level of the vanadium atom contains 5 electrons, which are valence electrons. The oxidation state of calcium is +5. The energy diagram of the ground state takes the following form:
Based on the diagram, it can be argued that vanadium also has an oxidation state of +3.
Examples of problem solving
EXAMPLE 1
| Exercise | Draw the distribution of electrons across energy levels and sublevels in silicon and vanadium atoms. What types of elements do they belong to in terms of atomic structure? |
| Answer | Silicon: 14 Si) 2) 8) 4 ; 1s 2 2s 2 2p 6 3s 2 3p 2 . Vanadium: 23 V) 2) 8) 11) 2 ; 1s 2 2s 2 2p 6 3s 2 3p 6 3d 3 4s 2 . Silicon belongs to the family p-, and vanadium d-elements. |
Vanadium
VANADIUM-I; m.[lat. Vanadium from Old Scand.] Chemical element (V), a hard metal of light gray color, used to make valuable grades of steel. ● Named after the Old Norse goddess of beauty Vanadis because of the beautiful color of its salts.
◁ Vanadium, -aya, -oh. Second ores. Second steel.
vanadium(lat. Vanadium), chemical element of group V of the periodic table. The name comes from the Old Norse goddess of beauty Vanadis. Steel gray hard metal. Density 6.11 g/cm 3 t pl 1920°C. Resistant to water and many acids. It is dispersed in the earth's crust and often accompanies iron (iron ores are an important industrial source of vanadium). Alloying component of structural steels and alloys used in aviation and space technology, marine shipbuilding, component of superconducting alloys. Vanadium compounds are used in the textile, paint and varnish, and glass industries.
VANADIUMVANADIUM (lat. Vanadium), V (read “vanadium”), chemical element with atomic number 23, atomic weight 50.9415. Natural vanadium is a mixture of two nuclides (cm. NUCLIDE): stable 51 V (99.76% by mass) and weakly radioactive 52 V (half-life more than 3.9 10 17 years). Configuration of two outer electronic layers 3 s 2
p 6
d 3
4s 2
. In Mendeleev's periodic table it is located in the fourth period in group VB. Vanadium forms compounds in oxidation states from +2 to +5 (valency from II to V).
The radius of the neutral vanadium atom is 0.134 nm, the radius of the V 2+ ions is 0.093 nm, V 3+ - 0.078 nm, V 4+ - 0.067-0.086 nm, V 5+ - 0.050-0.068 nm. The sequential ionization energies of the vanadium atom are 6.74, 14.65, 29.31, 48.6 and 65.2 eV. According to the Pauling scale, the electronegativity of vanadium is 1.63.
In its free form it is a shiny silver-gray metal.
History of discovery
Vanadium was discovered in 1801 by the Mexican mineralogist A. M. del Rio as an impurity in lead ore from a mine in Zimapan. Del Rio named the new element erythronium (from the Greek erythros - red) because of the red color of its compounds. However, he subsequently decided that he had not discovered a new element, but a variety of chromium, discovered four years earlier and still almost unstudied. In 1830, the German chemist F. Wöhler studied the Mexican mineral. (cm. WELER Friedrich) However, after being poisoned by hydrogen fluoride, he stopped research for several months. In the same year, the Swedish chemist N. Sefström (cm. SEFStröm Nils Gabriel) drew attention to the presence of an impurity in iron ore, which, along with the known elements, contained some new substance. As a result of analysis in the laboratory of J. Berzelius (cm. BERZELIUS Jens Jacob) it was proven that a new element had been discovered. This element forms compounds with beautiful colors, hence the name of the element, associated with the name of the Scandinavian goddess of beauty Vanadis. In 1831, Wöhler proved the identity of erythronium and vanadium, but the element retained the name given to it by Sefström and Berzelius.
Being in nature
Vanadium does not occur in nature in its free form; it is classified as a trace element. (cm. TRACE ELEMENTS). The content of vanadium in the earth's crust is 1.6 10 -2% by mass, in ocean water 3.10 -7%. The most important minerals: patronite V(S 2) 2, vanadinite Pb 5 (VO 4) 3 Cl and some others. The main source of vanadium is iron ores containing vanadium as an impurity.
Receipt
In industry, when obtaining vanadium from iron ores with its admixture, a concentrate is first prepared, in which the vanadium content reaches 8-16%. Next, by oxidative treatment, vanadium is transferred to the highest oxidation state +5 and sodium vanadate NaVO 3, easily soluble in water, is separated. When the solution is acidified with sulfuric acid, a precipitate forms, which after drying contains more than 90% vanadium.
The primary concentrate is reduced in blast furnaces and vanadium concentrate is obtained, which is then used in the smelting of an alloy of vanadium and iron - the so-called ferrovanadium (contains from 35 to 70% vanadium). Metallic vanadium can be prepared by reduction of vanadium chloride with hydrogen, calcium-thermal reduction of vanadium oxides (V 2 O 5 or V 2 O 3), thermal dissociation of VI 2 and other methods.
Physical and chemical properties
Vanadium is similar in appearance to steel; it is quite hard, but at the same time ductile metal. Melting point 1920 °C, boiling point about 3400 °C, density 6.11 g/cm3. The crystal lattice is cubic, body-centered, parameter a = 0.3024 nm.
Chemically, vanadium is quite inert. It is resistant to sea water, diluted solutions of hydrochloric, nitric and sulfuric acids, and alkalis. With oxygen, vanadium forms several oxides: VO, V 2 O 3, V 3 O 5, VO 2, V 2 O 5. Orange V 2 O 5 is an acidic oxide, dark blue VO 2 is amphoteric, the remaining vanadium oxides are basic. With halogens, vanadium forms halides of the compositions VX 2 (X = F, Cl, Br, I), VX 3, VX 4 (X = F, Cl, Br), VF 5 and several oxohalides (VOCl, VOCl 2, VOF 3, etc. .).
Vanadium compounds in oxidation states +2 and +3 are strong reducing agents; in oxidation state +5 they exhibit the properties of oxidizing agents. Refractory vanadium carbide VC (t pl =2800 °C), vanadium nitride VN, vanadium sulfide V 2 S 5, vanadium silicide V 3 Si and other vanadium compounds are known.
When V 2 O 5 interacts with basic oxides, vanadates are formed (cm. VANADATES)- vanadic acid salts of probable composition H 2 .
Application
Vanadium is mainly used as an alloying additive in the production of wear-resistant, heat-resistant and corrosion-resistant alloys (primarily special steels), and as a component in the production of magnets. Vanadium oxide V 2 O 5 serves as an effective catalyst, for example, in the oxidation of sulfur dioxide SO 2 into sulfur gas SO 3 in the production of sulfuric acid. Vanadium compounds find a variety of applications in various industries (textile, glass, paint and varnish, etc.).
Biological role
Vanadium is constantly present in the tissues of all organisms in minute quantities. In plants its content (0.1-0.2%) is significantly higher than in animals (1·10 –5 -1·10 –4%). Some marine organisms - bryozoans, mollusks and, especially, ascidians - are capable of concentrating vanadium in significant quantities (in ascidians, vanadium is found in the blood plasma or special cells - vanadocytes). Apparently, vanadium is involved in some oxidative processes in tissues. Human muscle tissue contains 2·10 - 6% vanadium, bone tissue - 0.35·10 - 6%, in blood - less than 2·10 - 4% mg/l. In total, the average person (body weight 70 kg) contains 0.11 mg of vanadium. Vanadium and its compounds are toxic. The toxic dose for humans is 0.25 mg, the lethal dose is 2-4 mg. For V 2 O 5 the maximum permissible concentration in air is 0.1-0.5 mg/m 3 .
Encyclopedic Dictionary. 2009 .
Synonyms:See what “vanadium” is in other dictionaries:
- (lat. vanadium). A fragile metal, white in color, discovered in 1830 and named after the Scandinavian deity Vanadium. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. VANADIUM lat. vanadium, named Vanadia,... ... Dictionary of foreign words of the Russian language
- (chemical value V, atomic weight 51) a chemical element similar to compounds with phosphorus and nitrogen. V. compounds are often found, although in negligible quantities, in iron ores and some clays; pre-processing of vanadic iron ores, V. part... ... Encyclopedia of Brockhaus and Efron
Vanad Dictionary of Russian synonyms. vanadium noun, number of synonyms: 2 vanadium (1) element... Dictionary of synonyms
VANADIUM- VANADIUM, chemical. sign V, at. V. 51.0, hard, elastic steel-colored metal, melting point 1715°, sp. weight 5.688. V. compounds are widespread in nature. These compounds are poisons, not inferior in strength to arsenic; they have... ... Great Medical Encyclopedia
- (Vanadium), V, chemical element of group V of the periodic system, atomic number 23, atomic mass 50.9415; metal, melting point 1920°C. Used for alloying steel and cast iron, as a component of heat-resistant, hard and corrosion-resistant alloys, as... Modern encyclopedia
- (lat. Vanadium) V, chemical element of group V of the periodic system, atomic number 23, atomic mass 50.9415. The name comes from the Old Norse goddess of beauty Vanadis. Steel gray hard metal. Density 6.11 g/cm³, melting point 1920 .C.… … Big Encyclopedic Dictionary
- (symbol V), TRANSITION ELEMENT, discovered in 1801. Silvery-white, malleable, tough metal. Found in IRON, LEAD AND URANIUM ores, as well as in coal and oil. Used in steel alloys to increase strength and heat resistance.… … Scientific and technical encyclopedic dictionary Physical encyclopedia
vanadium- V Element of group V Periodic. systems; at. n. 23, at. m. 50.942; steel gray metal. Natural V consists of two isotopes: 51V (99.75%) and 50V (0.25%). V was opened in 1801 Mexico. mineralogist A. M. del Rio. In prom. V scale... ... Technical Translator's Guide
Vanadium(vanadium), v, chemical element of group V of the periodic system of Mendeleev; atomic number 23, atomic mass 50.942; metal gray-steel color. Natural V. consists of two isotopes: 51 v (99.75%) and 50 v (0.25%); the latter is weakly radioactive (half-life T 1/2 = 10 14 years). V. was discovered in 1801 by the Mexican mineralogist A. M. del Rio in Mexican brown lead ore and was named after the beautiful red color of the heated salts erythronium (from the Greek erythr o s - red). In 1830, the Swedish chemist N. G. Sefström discovered a new element in iron ore from Taberg (Sweden) and named it V. in honor of the Old Norse goddess of beauty Vanadis. In 1869, the English chemist G. Roscoe obtained powdered metal V. by reducing vcl 2 with hydrogen. V. has been mined on an industrial scale since the beginning of the 20th century.
The V content in the earth's crust is 1.5-10 -2% by weight; it is a fairly common element, but dispersed in rocks and minerals. Of the large number of V. minerals, patronite, roscoelite, decloysite, carnotite, vanadinite, and some others are of industrial importance. Important sources of V. are titanomagnetite and sedimentary (phosphorous) iron ores, as well as oxidized copper-lead-zinc ores. V. is extracted as a by-product during the processing of uranium raw materials, phosphorites, bauxites, and various organic deposits (asphaltites, oil shale).
Physical and chemical properties. V. has a body-centered cubic lattice with a period a = 3.0282 å. In its pure state, V. is forged and can be easily processed by pressure. Density 6.11 G/ cm 3 , t pl 1900 ± 25°С, t bale 3400°C; specific heat capacity (at 20-100°C) 0.120 feces/ ggrad; thermal coefficient of linear expansion (at 20-1000°C) 10.6·10 -6 hail-1, electrical resistivity at 20 °C 24.8·10 -8 ohm· m(24.8·10 -6 ohm· cm), below 4.5 K V. it goes into a state of superconductivity. Mechanical properties of high purity V. after annealing: elastic modulus 135.25 n/ m 2 (13520 kgf/ mm 2), tensile strength 120 nm/ m 2 (12 kgf/ mm 2), elongation 17%, Brinell hardness 700 pl/ m 2 (70 kgf/ mm 2). Gas impurities sharply reduce the plasticity of fiber and increase its hardness and fragility.
At ordinary temperatures, V. is not exposed to air, sea water, and alkali solutions; resistant to non-oxidizing acids, with the exception of hydrofluoric acid. In terms of corrosion resistance in hydrochloric and sulfuric acids, V. is significantly superior to titanium and stainless steel. When heated in air above 300°C, it absorbs oxygen and becomes brittle. At 600-700°C, V. is intensively oxidized with the formation of pentoxide v 2 o 5, as well as lower oxides. When V is heated above 700°C in a nitrogen stream, nitride vn ( t mp 2050°C), stable in water and acids. V. interacts with carbon at high temperatures, giving refractory carbide vc ( t pl 2800°C), which has high hardness.
V. produces compounds corresponding to valences 2, 3, 4 and 5; Accordingly, the following oxides are known: vo and v 2 o 3 (having a basic character), vo 2 (amphoteric) and v 2 o 5 (acidic). Compounds of 2- and 3-valent vitreous are unstable and are strong reducing agents. Compounds of higher valences are of practical importance. V.'s tendency to form compounds of different valencies is used in analytical chemistry and also determines the catalytic properties of v 2 o 5. V. pentoxide dissolves in alkalis to form vanadates.
Receipt and application. To extract minerals, the following are used: direct leaching of ore or ore concentrate with solutions of acids and alkalis; firing of the raw material (often with nacl additives) followed by leaching of the fired product with water or dilute acids. Hydrated V pentoxide is isolated from solutions by hydrolysis (at pH = 1-3). When vanadium-containing iron ores are smelted in a blast furnace, V is converted into cast iron, during the processing of which slag containing 10-16% v 2 o 5 is obtained into steel. Vanadium slags are roasted with table salt. The burned material is leached with water and then with dilute sulfuric acid. V 2 o 5 is isolated from solutions. The latter is used for smelting ferrovanadium(iron alloys with 35-70% V.) and obtaining metal V. and its compounds. Malleable metal V. is obtained by calcium-thermal reduction of pure v 2 o 5 or v 2 o 3; reduction of v 2 o 5 with aluminum; vacuum carbon-thermal reduction v 2 o 3; magnesium-thermal reduction vc1 3; thermal dissociation of iodide. V. is melted in vacuum arc furnaces with a consumable electrode and in electron beam furnaces.
Ferrous metallurgy is the main consumer of metal (up to 95% of all metal produced). V. is a component of high-speed steel, its substitutes, low-alloy tool steels, and some structural steels. With the introduction of 0.15-0.25% V., the strength, toughness, fatigue resistance and wear resistance of steel sharply increase. V., introduced into steel, is both a deoxidizing and carbide-forming element. V. carbides, distributed in the form of dispersed inclusions, prevent grain growth when the steel is heated. V. is introduced into steel in the form of a master alloy - ferrovanadium. V. is also used for alloying cast iron. A new consumer of titanium is the rapidly developing industry of titanium alloys; some titanium alloys contain up to 13% V. In aviation, rocket and other fields of technology, alloys based on niobium, chromium and tantalum containing V additives have been used. Heat-resistant and corrosion-resistant alloys based on V with the addition of ti, nb have been developed. , w, zr and al, the use of which is expected in aviation, rocket and nuclear technology. Of interest are superconducting alloys and V compounds with ga, si and ti.
Pure metallic V. is used in nuclear energy (shells for fuel elements, pipes) and in the production of electronic devices.
V. compounds are used in the chemical industry as catalysts, in agriculture and medicine, in the textile, paint and varnish, rubber, ceramic, glass, photo and film industries.
V. compounds are poisonous. Poisoning is possible by inhaling dust containing compounds B. They cause irritation of the respiratory tract, pulmonary hemorrhages, dizziness, disturbances in the functioning of the heart, kidneys, etc.
V. in the body. V. is a constant component of plant and animal organisms. The source of water is igneous rocks and shales (containing about 0.013% water), as well as sandstones and limestones (about 0.002% water). In soils, V. is about 0.01% (mainly in humus); in fresh and sea waters 1·10 7 -2·10 7%. In terrestrial and aquatic plants, the content of V. is significantly higher (0.16-0.2%) than in terrestrial and marine animals (1.5·10 -5 -2·10 -4%). V. concentrators are: the bryozoan plumatella, the mollusk pleurobranchus plumula, the sea cucumber stichopus mobii, some ascidians, from molds - black aspergillus, from mushrooms - toadstool (amanita muscaria). The biological role of V. has been studied in ascidians, in whose blood cells V. is in a 3- and 4-valent state, that is, there is a dynamic equilibrium.
The physiological role of V. in ascidians is associated not with the respiratory transfer of oxygen and carbon dioxide, but with redox processes—the transfer of electrons using the so-called vanadium system, which probably has physiological significance in other organisms.
Lit.: Meerson G. A., Zelikman A. N., Metallurgy of rare metals, M., 1955; Polyakov A. Yu., Fundamentals of vanadium metallurgy, M., 1959; Rostoker U., Vanadium Metallurgy, trans. from English, M., 1959; Kieffer p., Brown H., Vanadium, niobium, tantalum, trans. from German, M., 1968; Handbook of Rare Metals, [trans. from English], M., 1965, p. 98-121; Refractory materials in mechanical engineering. Directory, M., 1967, p. 47-55, 130-32; Kovalsky V.V., Rezaeva L.T., The biological role of vanadium in ascidians, “Advances of modern biology”, 1965, v. 60, v. 1(4); Bowen N. j. M., trace elements in biochemistry, l. - n. y., 1966.
I. Romankov. V. V. Kovalsky.
Vanadium is a chemical element symbolized by the symbol "V". The atomic mass of vanadium is 50.9415 a. e.m., atomic number - 23. It is a hard silver-gray, malleable and fusible metal, rarely found in nature. It is found in over 60 minerals and can even be found in fossil fuels.
Unrecognized discovery
The metal vanadium was first discovered by Spanish-born Mexican mineralogist Andres Manuel Del Rio in 1801. A researcher has extracted a new element from a sample of “brown” lead ore mined in Mexico. As it turns out, the metal's salts have a wide variety of colors, so Del Rio originally named it "panchromium" (from the Greek "παγχρώμιο" - "multi-colored").
The mineralogist later renamed the element erythronium (from the Greek "ερυθρός" - "red"), because most salts turned red when heated. It would seem that incredible luck smiled on a little-known scientist in Europe. The discovery of the new chemical element vanadium promised, if not fame, then at least recognition from colleagues. However, due to the lack of significant authority in the scientific world, the Mexican’s achievement was ignored.
In 1805, the French chemist Hippolyte Victor Collet-Decotils suggested that the new element studied by Del Rio was just a sample of lead chromate with impurities. Ultimately, the Mexican researcher, in order not to completely lose face in front of the scientific fraternity, accepted Collet-Decotille's statement and abandoned his discovery. However, his achievement did not fade into oblivion. Today, Andres Manuel Del Rio is recognized as the discoverer of the rare metal.
Reopening
In 1831, the Swede Nils Gabriel Sefström rediscovered the chemical element vanadium in the oxide he obtained while working with iron ore. The scientist chose the letter “V” as its designation, which has not yet been assigned to any element. Säfström named the new metal because of its beautiful and rich coloring after the Old Norse goddess of beauty Vanadis.
The news aroused increased interest in the scientific community. We immediately remembered the work of the Mexican mineralogist. In the same 1831, Friedrich Wöhler rechecked and confirmed Del Rio's previous discovery. And geologist George William Featherstonhoop even proposed calling the metal “rionium” in honor of the discoverer, but the initiative was not supported.
Elusive
Isolating vanadium metal in its pure form has proven difficult. Before this, scientists worked only with its salts. That is why the true properties of vanadium are unknown. In 1831, Berzelius reported obtaining a metallized substance, but Henry Enfield Roscoe proved that Berzelius had actually produced vanadium nitride (VN). Roscoe eventually produced the metal in 1867 by reducing vanadium chloride (VCl 2) with hydrogen. Since 1927, pure vanadium has been obtained by reducing vanadium pentoxide with calcium.
The first serial industrial use of the element dates back to 1905. The metal was added to a steel alloy to make racing car chassis and later to the Ford Model T. Vanadium's characteristics help reduce structural weight while increasing tensile strength. By the way, the German chemist Martin Henze discovered vanadium in the blood cells (or coelomic cells) of marine inhabitants - accidia - in 1911.
Physical properties
Vanadium is a malleable gray-blue metal of medium hardness with a steely luster and a density of 6.11 g/cm³. Some sources describe the material as soft, meaning its high ductility. The crystal structure of the element is more complex than most metals and steels.
Vanadium has good resistance to corrosion, alkalis, sulfuric and hydrochloric acids. It oxidizes in air at about 660°C (933K, 1220°F), although passivation of the oxide occurs even at room temperature. This material melts when the temperature reaches 1920°C, and boils at 3400°C.
Chemical properties
Vanadium, when exposed to oxygen, forms four types of oxides:
Type (II) vanadium compounds are reducing agents, and type (V) compounds are oxidizing agents. Compounds (IV) often exist as derivatives of the vanadyl cation.
Oxide
The most commercially important compound is vanadium pentoxide. It is a brownish-yellow solid, although when freshly precipitated from aqueous solution its color is dark orange.
The oxide is used as a catalyst for the production of sulfuric acid. This compound oxidizes sulfur dioxide (SO 2) into trioxide (SO 3). In this redox reaction, sulfur is oxidized from +4 to +6, and vanadium is reduced from +5 to +4. The formula for vanadium is as follows:
V 2 O 5 + SO 2 → 2VO 2 + SO 3
The catalyst is regenerated by the oxidation of oxygen:
2VO 2 + O 2 → V 2 O 5
Similar oxidation processes are used in the production of maleic anhydride, phthalic anhydride and several other bulk organic compounds.
This oxide is also used in the preparation of ferrovanadium. It is heated with iron and ferrosilicon with the addition of lime. When aluminum is used, an iron-vanadium alloy is produced along with aluminum oxide as a by-product. Due to its high coefficient of thermal resistance, vanadium(V) oxide is used as a detector material in bolometers and microbolometer arrays in thermal imaging instruments.
Characteristics
Rare metal has the following characteristics:
- Crystal structure: body-centered cubic.
- Sound conductivity: 4560 m/s (at 20°C).
- Valence of vanadium: V (less often IV, III, II).
- Thermal expansion: 8.4 µm/(m K) (at 25°C).
- Thermal conductivity: 30.7 W/(m K).
- Electrical resistance: 197 nΩ m (at 20°C).
- Magnetism: paramagnetic.
- Magnetic susceptibility: +255·10 -6 cm 3 /mol (298K).
- Elastic modulus: 128 GPa.
- Shear modulus: 47 GPa.
- Bulk modulus of elasticity: 160 GPa.
- Poisson's ratio: 0.37.
- Hardness on the Mohs scale: 6.7.
- Vickers hardness: 628-640 MPa.
- Brinell hardness: 600-742 MPa.
- Element category: transition metal.
- Electronic configuration: 3d 3 4s 2.
- Heat of fusion: 21.5 kJ/mol.
- Heat of evaporation: 444 kJ/mol.
- Molar heat capacity: 24.89 J/(mol K).
Vanadium in the periodic table is in the 5th group (vanadium subgroup), 4th period, d-block.
Spreading
Vanadium on the scale of the Universe is approximately 0.0001% of the total volume of matter. It is as common as copper and zinc. The metal was discovered in the spectral glow of the Sun and other stars.
The element is the 20th most abundant in the earth's crust. The metal vanadium is quite rare in crystalline form, but compounds of this material are found in 65 different minerals. The economically significant of them are patronite (VS 4), vanadinite (Pb 5 (VO 4) 3 Cl) and carnotite (K 2 (UO 2) 2 (VO 4) 2 3 H 2 O).
Vanadyl ions are abundant in seawater and have an average concentration of 30 nMa. Some mineral water sources also contain these ions in high concentrations. For example, springs near Mount Fuji contain up to 54 µg/l.
Production
Most of this rare metal is derived from vanadium magnetite, found in ultramafic igneous gabbro rocks. The raw materials are mined mainly in South Africa, northwestern China and eastern Russia. In 2013, these countries produced more than 97% of all vanadium (79,000 tons by weight).
The metal is also present in bauxite and deposits of crude oil, coal, oil shale and tar sands. Concentrations up to 1200 ppm have been reported in crude oil. Due to the oxidizing properties of vanadium (some of its oxides), after combustion of such petroleum products, residues of the element can cause corrosion in engines and boilers.
An estimated 110,000 tons of the substance are released into the atmosphere each year by burning fossil fuels. Today, technologies are being developed to extract valuable substances from hydrocarbons.
Production
Vanadium is primarily used as an additive to steel alloys called ferroalloys. Ferrovanadium is produced directly by reducing a mixture of valence (V) vanadium oxide, iron oxides and pure iron in an electric furnace.
The metal is produced using a multi-step process that begins by roasting ground vanadium magnetite ore with the addition of sodium chloride (NaCl) or sodium carbonate (Na2CO3) at about 850°C to produce sodium metavanadate (NaVO3). An aqueous extract of this substance is acidified to obtain a polyvanadate salt, which is reduced with calcium metal. As an alternative to small-scale production, vanadium pentoxide is reduced with hydrogen or magnesium.
Many other methods are also used, all of which produce vanadium as a by-product of other processes. Its purification is possible using the iodide method, developed by Anton Eduard van Arkel and Jan Hendrik de Boer in 1925. It involves the formation of vanadium (III) iodide and its subsequent decomposition to produce pure metal:
2 V + 3I 2 ⇌ 2 VI 3
The Japanese came up with a rather exotic way to obtain this element. They breed ascidians (a type of chordata) in underwater plantations, which absorb vanadium from sea water. They are then collected and burned. Valuable metal is extracted from the resulting ash. By the way, its concentration in this case is much higher than in the richest deposits.
Alloys
What are vanadium alloys? Approximately 85% of the rare metal produced is used to produce ferrovanadium or as an additive to steel. At the beginning of the 20th century, it was discovered that even a small amount of vanadium significantly increases the strength of steel. This element forms stable nitrides and carbides, which leads to improved characteristics of steels and alloys.
Since that time, vanadium has been used in axles, frames, crankshafts, gears and other important components of wheeled vehicles. There are two groups of alloys:
- High carbon with a content of 0.15% to 0.25% vanadium.
- High-speed tool steels (HSS) containing from 1% to 5% of this element.
Hardnesses above HRC 60 can be achieved for HSS grade steels. They are used in surgical instruments. In powder metallurgy, alloys can contain up to 18% vanadium. The high carbide content in these alloys significantly increases wear resistance. Tools and knives are made from them.
Due to its properties, vanadium stabilizes the beta form of titanium, increases its strength and temperature stability. Mixed with aluminum in titanium alloys, it is used in jet engines, high-speed aircraft and dental implants. The most common alloy for seamless pipes is titanium 3/2.5, containing 2.5% vanadium. These materials are widely used in the aerospace, defense and bicycle industries. Another common alloy, produced primarily in sheets, is titanium 6AL-4V, which is 6% aluminum and 4% vanadium.
Several vanadium alloys exhibit superconducting properties. The first phase superconductor A15 was a vanadium compound V 3 Si, which was obtained in 1952. Vanadium gallium tape is used in superconducting magnets. The structure of the superconducting phase A15 V 3 Ga is similar to the structure of more common superconductors: triniobium stannibide (Nb 3 Sn) and niobium titanium (Nb 3 Ti).
Recently, scientists have discovered that in the Middle Ages, small amounts of vanadium (from 40 to 270 parts per million) were added to some samples of Damascus and damask steel. This improved the properties of the blades. However, it is unclear where and how the rare metal was mined. Perhaps it was part of some ores.
Application
In addition to metallurgy, vanadium is used for other applications. The thermal neutron capture cross section and short half-life of the isotopes produced by neutron capture make the metal a suitable material for use inside a fusion reactor.
The most common vanadium oxide, V 2 O 5 pentoxide, is used as a catalyst in the production of sulfuric acid and as an oxidizing agent in the production of maleic anhydride. Vanadium foam is used in the manufacture of ceramic products.
The metal is an important component of mixed metal oxide catalysts used in the oxidation of propane and propylene to acrolein, acrylic acid, or the ammoxidation of propylene to acrylonitrile. Another vanadium oxide, VO 2 dioxide, is used in the production of glass coatings that block infrared radiation at certain temperatures.
A vanadium redox battery is a voltaic cell consisting of aqueous vanadium ions in various oxidation states. Batteries of this type were first proposed in the 1930s, and commercial use began in the 1980s. Vanadate can be used to protect steel from corrosion.
Vanadium is important for human health. It helps regulate carbon and lipid metabolism and is involved in energy production. It is recommended to consume 6-63 mcg per day (WHO data) of the substance from food. It is quite sufficient in cereals, legumes, vegetables, herbs, and fruits.