Vanadium: properties, atomic mass, formula, application. Vanadium valence

Vanadium(vanadium), v, chemical element of group V periodic table 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.

Contents of V. in earth's crust makes up 1.5-10 -2% by mass; it is a fairly common element, but dispersed in rocks and minerals. From large number The most important minerals of V. are patronite, roscoelite, decloysite, carnotite, vanadinite, and some others. 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, specific electrical resistance 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. gives 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. Practical significance have compounds of higher valences. 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 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.

Opening this chemical element happened twice. For the first time at the beginning of the 19th century, professor of mineralogy Del Rio identified this mineral in lead ores of rocks. European chemists were skeptical about this discovery.

In the 30s of the 19th century, the chemist Sefstrom from Sweden identified an admixture of an unidentified metal with multi-colored compounds in the composition of iron ore. Thanks to such a beautiful appearance, scientists called it Vanadium, which translated from the Old Norse language means the goddess of beauty.

Vanadium: characteristics of a microelement

Vanadium in the periodic table of Mendeleev is a secondary subgroup of the fifth group of the fourth period. It has atomic number 23 and is also characterized by a silvery-steel color and excellent malleability.

Natural places of microelement localization

Vanadium belongs to a group of chemical elements that are practically independent form minerals or concentrated deposits cannot be found in nature. Their localization sites are various minerals. Among which it is worth highlighting sedimentary and magnetic rocks, shales and iron ore. The main deposits include Australia, Turkey, South Africa and some territorial areas in Russia.

The human body accumulates vanadium in the following places:

• Adipose tissue.
• Bone.
• Subcutaneous immune cells.

Basic properties of vanadium

Visually similar to steel. This is a metal with high ductility. Its melting point is over 1900 degrees. Vanadium is not exposed to oxygen, salt water and alkali, provided that normal temperature conditions are maintained.

How much vanadium does a person need per day?

Average daily value of this microelement for healthy person is no more than 2 mg. Characteristic feature The absorption of this microelement in the body is the absorption of only 1% of the amount of vanadium consumed. The rest of it is excreted from the body naturally. Excess permissible norm leads to severe intoxication of the body, this, of course, negative property vanadium

What foods contain vanadium?

Reception pharmaceuticals containing vanadium is prescribed very rarely. Enrichment of the body with this microelement is carried out through the systematic consumption of the following products:

• Cereals.
• Rice and buckwheat groats.
• Beans.
• Vegetables.
• Fruits.
• Berries.

Positive effects of vanadium on the body

Vanadium is an essential microelement that is necessary to regulate the metabolism of fats and carbohydrates. In addition, it activates energy production. Reducing cholesterol levels is directly related to the concentration of vanadium in the body. It also stimulates the movement of blood cells, which promotes faster absorption of pathogens.

Combinations of vanadium with other substances

The toxic effect of vanadium on the body can be reduced by simultaneous consumption of chromium and a large amount of protein-containing foods. Ascorbic acid, iron or aluminum compounds have a negative effect on the body.

Vanadium deficiency

IN medical practice There is a single case of vanadium deficiency in the body, which manifests itself in the form of deficiency schizophrenia. A lack of vanadium in the body increases the likelihood of developing diabetes mellitus, atherosclerosis as a result of low cholesterol levels and higher level triglycerides, and phospholipids.

The main signs of excess vanadium in the body

Oversaturation of the body with vanadium is quite common. In order to control the amount of this substance entering the body, you should be careful about your diet and monitor the slightest physiological deviations in the body.

The main signs of an excess of vanadium include:

• Allergic reaction.
• Anemia.
• Multiple sclerosis.
• The development of inflammation on the mucous membranes and skin.
• Damage to the upper respiratory organs.
• Presence of neoplasms.
• Development of depressive neurosis.
• Bipolar affective disorder.

Vanadium in human life

The metallurgical industry is the main consumer of vanadium in its operations. It is used to produce stainless alloys, which are used to make high-speed steel tools. They are characterized by high strength and wear resistance.

In addition, vanadium is an integral component of atomic hydrogen energy; it is used in the production of synthetic sulfuric acid. Vanadium is also used as a source of chemical current.

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 due to beautiful color their 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.

VANADIUM

VANADIUM (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 a neutral vanadium atom is 0.134 nm, the radius of V 2+ ions is 0.093 nm, V 3+ is 0.078 nm, V 4+ is 0.067-0.086 nm, V 5+ is 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%. Essential 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- 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 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... Synonym dictionary

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 is an element of the side subgroup of the fifth group, the fourth period of the periodic system of chemical elements of D.I. Mendeleev, with atomic number 23. It is designated by the symbol V (lat. Vanadium). The simple substance vanadium is a ductile metal of silver-gray color.

1. History of discovery

First vanadium was actually discovered in 1781 by a professor of mineralogy from Mexico City, Andres Manuel Del Rio, in lead ores. He discovered a new metal and proposed the name "panchromium" for it due to the wide range of colors of its compounds, later changing it to "erythronium". Del Rio had no authority in scientific world Europe, and European chemists doubted his results. Then Del Rio himself lost confidence in his discovery and declared that he had discovered only lead chromate.

In 1830, vanadium was rediscovered in iron ore by the Swedish chemist Nils Säfström. The name of the new element was given by Berzelius and Sefström.

Friedrich Wöhler, who was exploring Mexican ore, had a chance to discover vanadium, but shortly before Sefström’s discovery, he was seriously poisoned by hydrogen fluoride and was unable to continue his research. However, Wöhler completed the study of the ore and finally proved that it contained vanadium and not chromium.

1. Being in nature

Vanadium is a trace element and is not found in free form in nature. The vanadium content in the earth's crust is 1.6 × 10 −2% by mass, in ocean water 3 × 10 −7%. The highest average vanadium contents in igneous rocks are observed in gabbro and basalts (230-290 g/t). In sedimentary rocks, significant accumulation of vanadium occurs in biolites (asphaltites, coals, bituminous phosphates), bituminous shales, bauxites, as well as in oolitic and siliceous-iron ores. The proximity of the ionic radii of vanadium and that of iron and titanium, which are widespread in igneous rocks, leads to the fact that vanadium in hypogene processes is entirely in a dispersed state and does not form its own minerals. Its carriers are numerous titanium minerals (titanomagnetite, sphene, rutile, ilmenite), micas, pyroxenes and garnets, which have an increased isomorphic capacity with respect to vanadium. 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.

Place of Birth

There are known deposits in Peru, Colorado, USA, South Africa, Finland, Australia, Armenia, and Russia.

1. Obtaining vanadium

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 (Na) 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 to produce vanadium concentrate, which is then used in the smelting of an alloy of vanadium and iron - the so-called ferrovanadium (contains from 35 to 80% vanadium). Metallic vanadium can be prepared by reduction of vanadium chloride with hydrogen (H), calcium-thermal reduction of vanadium oxides (V 2 O 5 or V 2 O 3), thermal dissociation of VI 2 and other methods

1. Physical properties

Vanadium is a ductile metal of silver-gray color, similar in appearance to steel. Body-centered cubic crystal lattice, a=3.024 Å, z=2, space group Im3m. Melting point 1920 °C, boiling point 3400 °C, density 6.11 g/cm³. When heated in air above 300 °C, vanadium becomes brittle. Impurities of oxygen, hydrogen and nitrogen sharply reduce the plasticity of vanadium and increase its hardness and brittleness.

1. Chemical properties

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, 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. Vanadium halides are hydrolyzed. With halogens, vanadium forms fairly volatile 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 and 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 - vanadic acid salts of the probable composition HVO 3.

1. Application

80% of all vanadium produced is used in alloys, mainly for stainless and tool steels.

Vanadium steel is used for plating ship hulls. Increasing competition in shipbuilding is intensifying the introduction of steels that allow high-speed welding in wet environments. The use of vanadium in the production of alloys based on titanium and other refractory metals intended for new technology (aviation, rocket, nuclear energy) is expanding. The vanadium content in these alloys is 0.8-6.0%. Vanadium in combination with aluminum is used to impart the required strength to titanium alloys, which are used to create special bathyspheres for ocean exploration at a depth of 10,000 m. The addition of vanadium to aluminum alloys improves their heat resistance and weldability.

Nuclear-hydrogen energy:

Vanadium chloride is used in the thermochemical decomposition of water in nuclear-hydrogen energy (vanadium-chloride cycle of General Motors, USA). In metallurgy, vanadium is designated by the letter F.

Chemical current sources:

Vanadium pentoxide is widely used as a positive electrode (anode) in high-power lithium batteries and accumulators. Silver vanadate in backup batteries as a cathode.

1. Biological role and effects

It has been established that vanadium can inhibit the synthesis of fatty acids and suppress the formation of cholesterol. Vanadium inhibits a number of enzyme systems, inhibits phosphorylation and ATP synthesis, reduces the level of coenzymes A and Q, stimulates the activity of monoamine oxidase and oxidative phosphorylation. It is also known that in schizophrenia the vanadium content in the blood increases significantly.

Excessive intake of vanadium into the body is usually associated with environmental and industrial factors. When acutely exposed to toxic doses of vanadium, workers experience local inflammatory reactions skin and mucous membranes of the eyes, upper respiratory tract, accumulation of mucus in the bronchi and alveoli. There are also systemic allergic reactions types of asthma and eczema; as well as leukopenia and anemia, which are accompanied by disturbances in the basic biochemical parameters of the body.

When vanadium is administered to animals (in doses of 25-50 mcg/kg), growth retardation, diarrhea and increased mortality are noted.

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.

An increased content of proteins and chromium in the diet reduces the toxic effect of vanadium. Consumption standards for this mineral matter not installed.

In addition, vanadium in some organisms, for example, in marine inhabitants of the bottom of holothurians and ascidians, is concentrated in the coelomic fluid/blood, and its concentrations reach 10%! That is, these animals are a biological concentrator of vanadium. Its function in the body of sea cucumbers is not completely clear; different scientists consider it to be responsible either for the transfer of oxygen in the body of these animals, or for the transfer nutrients. From the point of view of practical use, it is possible to extract vanadium from these organisms; the economic payback of such “sea plantations” is currently unclear, but there are trial options in Japan.

1. Isotopes

Natural vanadium consists of two isotopes: weakly radioactive 50 V (isotopic abundance 0.250%) and stable 51 V (99.750%). The half-life of vanadium-50 is 1.5 x 10 17 years, i.e., for all practical purposes it can be considered stable; this isotope in 83% of cases turns into 50 Ti through electron capture, and in 17% of cases it undergoes beta minus decay, turning into 50 Cr. There are 24 known artificial radioactive isotopes of vanadium with a mass number from 40 to 65 (as well as 5 metastable states). Of these, the most stable is 49 V ( T 1/2 =337 days) and 48 V ( T 1/2 =15.974 days).

Lithium

Lithium (lat. Lithium; denoted by the symbol Li) is an element of the main subgroup of the first group, the second period of the periodic system of chemical elements of D.I. Mendeleev, with atomic number 3. The simple substance lithium is a soft alkali metal of a silvery-white color.

1. History of discovery

Lithium was discovered in 1817 by the Swedish chemist and mineralogist A. Arfvedson, first in the mineral petalite (Li, Na), and then in spodumene LiAl and in lepidolite KLi 1.5 Al 1.5 (F,OH) 2. Lithium metal was first discovered by Humphry Davy in 1825.

Lithium received its name due to the fact that it was discovered in “stones” (Greek λίθος - stone). Originally called "lithion" modern name was proposed by Berzelius.

1. Being in nature

Geochemistry of lithium:

According to its geochemical properties, lithium belongs to the large-ion lithophile elements, including potassium, rubidium and cesium. The lithium content in the upper continental crust is 21 g/t, in sea ​​water 0.17 mg/l.

The main lithium minerals are lepidolite mica - KLi 1.5 Al 1.5 (F, OH) 2 and spodumene pyroxene - LiAl. When lithium does not form independent minerals, it isomorphically replaces potassium in widespread rock-forming minerals.

Lithium deposits are confined to rare-metal granite intrusions, in connection with which lithium-bearing pegmatites or hydrothermal complex deposits also develop, containing tin, tungsten, bismuth and other metals. It is worth especially noting the specific rocks of ongonites - granites with igneous topaz, high content fluorine and water, and exceptionally high concentrations of various rare elements, including lithium.

Another type of lithium deposits is the brines of some highly saline lakes.

Place of Birth:

Lithium deposits are known in Russia, Argentina, Mexico, Afghanistan, Chile, USA, Canada, Brazil, Spain, Sweden, China, Australia, Zimbabwe, Congo.

1. Obtaining Lithium

Currently, to obtain lithium metal, its natural minerals are either decomposed with sulfuric acid (acid method), or sintered with CaO or CaCO 3 (alkaline method), or treated with K 2 SO 4 (salt method), and then leached with water. In any case, poorly soluble lithium carbonate Li 2 CO 3 is isolated from the resulting solution, which is then converted into LiCl chloride. Electrolysis of the lithium chloride melt is carried out in a mixture with KCl or BaCl 2 (these salts serve to lower the melting point of the mixture).

2LiCl(l) = 2Li + Cl2

The resulting lithium is subsequently purified by vacuum distillation.

1. Physical properties

Lithium is a silvery-white metal, soft and ductile, harder than sodium but softer than lead. It can be processed by pressing and rolling.

At room temperature, lithium metal has a body-centered cubic lattice (coordination number 8), which upon cold processing transforms into a cubic close-packed lattice, where each atom having a double cuboctahedral coordination is surrounded by 12 others. Below 78 K, the stable crystal form is a hexagonal close-packed structure in which each lithium atom has 12 nearest neighbors located at the vertices of a cuboctahedron.

Of all the alkali metals, lithium is characterized by the most high temperatures melting and boiling (180.54 and 1340 °C, respectively), it has the highest low density at room temperature among all metals (0.533 g/cm³, almost half the density of water).

The small size of the lithium atom leads to the appearance of special properties of the metal. For example, it mixes with sodium only at temperatures below 380 ° C and does not mix with molten potassium, rubidium and cesium, while other pairs of alkali metals mix with each other in any ratio.

1. Chemical properties

Lithium is an alkali metal, but is relatively stable in air. Lithium is the least active alkali metal; it practically does not react with dry air (and even dry oxygen) at room temperature. For this reason, lithium is the only alkali metal that is not stored in kerosene (and the density of lithium is so low that it will float in it) and can be stored in air for a short time.

In humid air, it slowly reacts with nitrogen in the air, turning into Li 3 N nitride, LiOH hydroxide and Li 2 CO 3 carbonate. When heated in oxygen, it burns, turning into Li 2 O oxide. Yes interesting feature, that in the temperature range from 100 °C to 300 °C, lithium is covered with a dense oxide film and does not subsequently oxidize.

In 1818, the German chemist Leopold Gmelin established that lithium and its salts color the flame carmine red, this is a qualitative sign for the determination of lithium. The combustion temperature is about 300 °C. Combustion products irritate the mucous membrane of the nasopharynx.

Reacts calmly, without explosion or fire, with water, forming LiOH and H 2 . It also reacts with ethyl alcohol (to form an alcoholate), with hydrogen (at 500-700 °C) to form lithium hydride, with ammonia and with halogens (with iodine - only when heated). At 130 °C it reacts with sulfur to form sulfide. In a vacuum at temperatures above 200 °C, it reacts with carbon (acetylide is formed). At 600–700 °C, lithium reacts with silicon to form silicide. Chemically soluble in liquid ammonia (-40 °C), a blue solution is formed.

Lithium is stored in petroleum ether, paraffin, gasoline and/or mineral oil in hermetically sealed tin boxes. Lithium metal causes burns if it comes into contact with the skin, mucous membranes and eyes.

1. Application

Thermoelectric materials:

An alloy of lithium sulfide and copper sulfide is an effective semiconductor for thermoelectric converters (emf about 530 μV/K).

Chemical current sources:

Anodes are made from lithium chemical sources current (batteries, e.g. lithium chloride batteries) and voltaic cells with solid electrolyte (e.g. lithium chromium-silver, lithium bismuthate, lithium copper oxide, lithium manganese dioxide, lithium lead iodine, lithium iodine, lithium thionyl chloride, lithium vanadium oxide , lithium-copper fluoride, lithium-sulfur dioxide elements), working on the basis of non-aqueous liquid and solid electrolytes (tetrahydrofuran, propylene carbonate, methyl formate, acetonitrile).

Lithium cobaltate and lithium molybdate have shown better performance properties and energy capacity as the positive electrode of lithium batteries.

Lithium hydroxide is used as one of the components for preparing the electrolyte of alkaline batteries. Adding lithium hydroxide to the electrolyte of traction iron-nickel, nickel-cadmium, nickel-zinc batteries increases their service life by 3 times and capacity by 21% (due to the formation of lithium nickelates).

Lithium aluminate is the most effective solid electrolyte (along with cesium beta alumina).

Laser materials:

Lithium fluoride single crystals are used for the manufacture of highly efficient (80% efficiency) free color center lasers and for the manufacture of optics with a wide spectral bandwidth.

Oxidizing agents:

Lithium perchlorate is used as an oxidizing agent.

Flaw detection:

Lithium sulfate is used in flaw detection.

Pyrotechnics:

Lithium nitrate is used in pyrotechnics.

Alloys:

Lithium alloys with silver and gold, as well as copper, are very effective solders. Lithium alloys with magnesium, scandium, copper, cadmium and aluminum are new promising materials in aviation and astronautics. Based on lithium aluminate and silicate, ceramics have been created that harden at room temperature and are used in military technology, metallurgy, and, in the future, in thermonuclear energy. Glass made from lithium aluminum silicate, strengthened by silicon carbide fibers, has enormous strength. Lithium is very effective in strengthening lead alloys and giving them ductility and resistance to corrosion.

Electronics:

Lithium cesium triborate is used as an optical material in radio electronics. Crystalline lithium niobate LiNbO 3 and lithium tantalate LiTaO 3 are nonlinear optical materials and are widely used in nonlinear optics, acousto-optics and optoelectronics. Lithium is also used to fill gas-discharge metal halide lamps.

Metallurgy:

In ferrous and non-ferrous metallurgy, lithium is used to deoxidize and increase the ductility and strength of alloys. Lithium is sometimes used to recover rare metals using metallothermy methods.

Aluminum metallurgy:

Lithium carbonate is the most important auxiliary substance (added to the electrolyte) in aluminum smelting and its consumption is growing every year in proportion to the volume of global aluminum production (lithium carbonate consumption is 2.5-3.5 kg per ton of aluminum smelted).

Aluminum alloying:

The introduction of lithium into the alloying system makes it possible to obtain new aluminum alloys with high specific strength.

The addition of lithium reduces the density of the alloy and increases the elastic modulus. With a lithium content of up to 1.8%, the alloy has low resistance to stress corrosion, and at 1.9% the alloy is not prone to stress corrosion cracking. An increase in lithium content to 2.3% increases the likelihood of formation of looseness and cracks. In this case, the mechanical properties change: the limits of strength and fluidity increase, and the plastic properties decrease.

The most well-known alloying systems are Al-Mg-Li (for example, alloy 1420, used for the manufacture of aircraft structures) and Al-Cu-Li (for example, alloy 1460, used for the manufacture of containers for liquefied gases).

Nuclear energy:

The 6 Li and 7 Li isotopes have different nuclear properties (thermal neutron absorption cross section, reaction products) and their scope is different. Lithium hafniate is part of a special enamel intended for the disposal of high-level nuclear waste containing plutonium.

Lithium-6 (fusion):

Used in thermonuclear energy.

When 6 Li nuclide is irradiated with thermal neutrons, radioactive tritium 3 1 H (T) is obtained:

6 3 Li + 1 0 n= 3 1 H + 4 2 He.

Thanks to this, lithium-6 can be used as a replacement for radioactive, unstable and inconvenient to handle tritium for both military (thermonuclear weapons) and peaceful (controlled thermonuclear fusion) purposes. Fusion weapons typically use lithium-6 deuteride 6 LiD.

It is also promising to use lithium-6 to produce helium-3 (via tritium) for further use in deuterium-helium thermonuclear reactors.

Lithium-7 (coolant):

Used in nuclear reactors using reactions involving heavy elements such as uranium, thorium or plutonium.

Thanks to the very high specific heat capacity and low thermal neutron capture cross section, liquid lithium-7 (often alloyed with sodium or cesium-133) serves as an effective coolant. Lithium-7 fluoride alloyed with beryllium fluoride (66% LiF + 34% BeF 2) is called “flybe” (FLiBe) and is used as a highly efficient coolant and solvent for uranium and thorium fluorides in high-temperature molten salt reactors and for the production of tritium.

Drying gases:

Highly hygroscopic bromide LiBr and lithium chloride LiCl are used for drying air and other gases.

Medicine:

Lithium salts have a psychotropic effect and are used in medicine for the prevention and treatment of a number of mental illnesses. The most common type of this material is lithium carbonate. Used in psychiatry to stabilize the mood of people suffering bipolar disorder and frequent mood swings. It is effective in preventing mania depression and reduces the risk of suicide. Doctors have repeatedly observed that certain lithium compounds (in appropriate doses, of course) have a positive effect on patients suffering from manic depression. This effect can be explained in two ways. On the one hand, it has been established that lithium is able to regulate the activity of some enzymes involved in the transfer of sodium and potassium ions from the intercellular fluid into brain cells. On the other hand, it has been noted that lithium ions directly affect the ionic balance of the cell. And the patient’s condition largely depends on the balance of sodium and potassium: an excess of sodium in the cells is typical for depressed patients, a deficiency - for those suffering from mania. By leveling the sodium-potassium balance, lithium salts have a positive effect on both. Lithium nicotinate (lithium salt nicotinic acid, lithonite) is used as a nonspecific remedy for the treatment of patients with alcoholism; the drug improves metabolic processes and hemodynamics, reduces affective disorders.

Lubricants:

Lithium stearate ("lithium soap") is used as a high temperature lubricant.

Oxygen regeneration in autonomous devices:

Lithium hydroxide LiOH, peroxide Li 2 O 2 and superoxide LiO 2 are used to purify air from carbon dioxide; in this case, the last two compounds react to release oxygen (for example, 4LiO 2 + 2CO 2 → 2Li 2 CO 3 + 3O 2), due to which they are used in insulating gas masks, in cartridges for air purification on submarines, on manned spacecraft, etc. d.

Silicate industry:

Lithium and its compounds are widely used in the silicate industry for the production of special types of glass and coating of porcelain products.

Other applications:

Lithium compounds are used in the textile (fabric bleaching), food (canning) and pharmaceutical (cosmetics) industries.

1. Lithium isotopes

Natural lithium consists of two stable isotopes: 6 Li (7.5%) and 7 Li (92.5%); In some lithium samples, the isotopic ratio may be greatly disturbed due to natural or artificial isotope fractionation. This should be kept in mind when performing precise chemical experiments using lithium or its compounds. Lithium has 7 artificial radioactive isotopes and two nuclear isomers (4 Li - 12 Li and 10m1 Li - 10m2 Li, respectively). The most stable of these, 8 Li, has a half-life of 0.8403 s. The exotic isotope 3 Li (triproton) does not appear to exist as a bound system.

7 Li is one of the few isotopes that arose during primordial nucleosynthesis (that is, shortly after the Big Bang). The formation of the element lithium in stars is possible by nuclear reaction“chipping” of heavier elements.

Conclusion:

Both of the chemical elements discussed above are an integral part of our life, since without at least one of them the existence of any branch of specialization is impossible.

Lithium and Vanadium are both metals that are not very similar to each other, but each of them plays a significant role in application.

Bibliography:

To create this work, materials from the site were used:

1. ru.wikipedia.org/wiki/Lithium
2. ru.wikipedia.org/wiki/Vanadium
3. http://www.krugosvet.ru/enc/nauka_i_tehnika/himiya/LITI.html
4. http://www.xumuk.ru/encyklopedia/2344.html
5. http://chem100.ru/elem.php?n=3
6. http://revolutionpedagogics/00228636.html

MOSCOW DEPARTMENT OF EDUCATION

STATE EDUCATIONAL INSTITUTION

SECONDARY VOCATIONAL EDUCATION

POLYTECHNIC COLLEGE No. 19

ABSTRACT ON "CHEMISTRY"

SUBJECT: VANADIUM AND LITHIUM

Is done by a student

1st year 1VM1 group

Kapustyansky Vladislav

Aleksandrovich

Checked by: teacher

Denis Alexandrovich

Moscow, 2010

Vanadium:

1. History of discovery
2. Being in nature

Place of Birth

1. Obtaining vanadium
2. Physical properties
3. Chemical properties
4. Application

Nuclear-hydrogen energy

Chemical current sources

1. Biological role and effects
2. Isotopes

Lithium:

1. History of discovery
2. Being in nature

Geochemistry

Place of Birth

1. Obtaining Lithium
2. Physical properties
3. Chemical properties
4. Application

Thermoelectric materials

Chemical current sources

Laser materials

Oxidizing agents

Flaw detection

Pyrotechnics

Electronics

Metallurgy

Nuclear electronics

Drying gases

Medicine

Lubricants

Oxygen regeneration in autonomous devices

Silicate industry

Other areas

1. Lithium isotopes

VANADIUM (Vanadium), V (a. vanadium; n. Vanadin; f. vanadium; i. vanadio), is a chemical element of group V of the periodic system of Mendeleev, atomic number 23, atomic mass 50.94. Two stable isotopes of vanadium are known in nature: 50 V (0.25%) and 51 V (99.75%). Discovered by the Mexican mineralogist A. M. del Rio in 1801.

Preparation and use of vanadium

Metallic vanadium (95-99% V) is obtained by carbo-, calcium- and magnesium-thermal reduction of technical V 2 O 5 or thermal dissociation of vanadium iodide. To obtain vanadium of high purity, its refining is used: electrolysis of molten vanadium halides, simple and zone induction, arc and electron beam melting in a vacuum. About 90% of vanadium is consumed ferrous metallurgy, where it is used as an alloying additive to steel and cast iron. Various alloys are also created based on vanadium, which, along with metal vanadium, are used as a structural material in nuclear reactors, and alloys based on Ti with vanadium additives are used in aviation and rocket technology. In the chemical industry, vanadium compounds are used as catalysts in the contact production of sulfuric acid; used in paint, rubber, textile, ceramic and other industries.