antimony valency. The structure of the antimony atom. Everywhere but the sun

DEFINITION

Antimony is the fifty-first element of the Periodic Table. Designation - Sb from the Latin "stibium". It is located in the fifth period, VA group. Refers to semimetals. The nuclear charge is 51.

Antimony occurs in nature in combination with sulfur - in the form of antimony gloss] 6 or antimonite, Sb 2 S 3. Despite the fact that the content of antimony in the earth's crust is relatively small, antimony has been known since ancient times. This is due to the prevalence of antimony luster in nature and the ease of obtaining antimony from it.

In the free state, antimony forms silver-white crystals (Fig. 1), which have a metallic luster and have a density of 6.68 g/cm 3 . Resembling metal in appearance, crystalline antimony is brittle and conducts heat and electric current much worse than ordinary metals. In addition to crystalline antimony, its other allotropic modifications are also known.

Rice. 1. Antimony. Appearance.

Atomic and molecular weight of antimony

Relative molecular weight of a substance(M r) is a number showing how many times the mass of a given molecule is greater than 1/12 of the mass of a carbon atom, and relative atomic mass of an element(A r) - how many times the average mass of atoms of a chemical element is greater than 1/12 of the mass of a carbon atom.

Since antimony exists in the free state in the form of monatomic Sb molecules, the values ​​of its atomic and molecular masses coincide. They are equal to 121.760.

Isotopes of antimony

It is known that antimony can occur in nature in the form of two stable isotopes 121Sb (57.36%) and 123Sb (42.64%). Their mass numbers are 121 and 123, respectively. The nucleus of an atom of the antimony isotope 121 Sb contains fifty-one protons and seventy neutrons, and the isotope 123 Sb contains such a number of protons and seventy-two neutrons.

There are artificial unstable isotopes of antimony with mass numbers from 103 to 139, as well as more than twenty isomeric states of nuclei, among which the 125Sb isotope with a half-life of 2.76 years is the longest-lived.

antimony ions

On the outer energy level of the antimony atom, there are five electrons that are valence:

1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 4d 10 5s 2 5p 3 .

As a result of chemical interaction, antimony gives up its valence electrons, i.e. is their donor, and turns into a positively charged ion or accepts electrons from another atom, i.e. is their acceptor and turns into a negatively charged ion:

Sb 0 -3e → Sb 3+;

Sb 0 -5e → Sb 5+;

Sb 0 +3e → Sb 3- .

Molecule and atom of antimony

In the free state, antimony exists in the form of monatomic Sb molecules. Here are some properties that characterize the atom and molecule of antimony:

Antimony alloys

Antimony is added to some alloys to harden them. An alloy consisting of antimony, lead and a small amount of tin is called typographic metal, or hart, and is used to make typographic type. From an alloy of antimony with lead (from 5 to 15% Sb), plates of lead accumulators, sheets and pipes for the chemical industry are made.

Examples of problem solving

EXAMPLE 1

atomic number	51
Appearance of a simple substance	silver white metal
Atom properties
Atomic mass (molar mass)	121.760 a. e. m. (/mol)
Atom radius	159 pm
Ionization energy (first electron)	833.3 (8.64) kJ/mol (eV)
Electronic configuration	4d 10 5s 2 5p 3
Chemical properties
covalent radius	140 pm
Ion radius	(+6e)62 (-3e)245 pm
Electronegativity (according to Pauling)	2,05
Electrode potential	0
Oxidation states	5, 3, −3
Thermodynamic properties of a simple substance
Density	6.691 /cm³
Molar heat capacity	25.2 J /( mol)
Thermal conductivity	24.43 W /( )
Melting temperature	903,9
Melting heat	20.08 kJ/mol
Boiling temperature	1908
Heat of evaporation	195.2 kJ/mol
Molar volume	18.4 cm³/mol
The crystal lattice of a simple substance
Lattice structure	trigonal
Lattice parameters	4,510
c/a ratio	n/a
Debye temperature	200,00

Sb	51
121,760
4d 10 5s 2 5p 3

- an element of the main subgroup of the fifth group of the fifth period of the periodic system of chemical elements of D. I. Mendeleev, atomic number 51. It is designated by the symbol Sb (lat. Stibium). The simple substance antimony (CAS number: 7440-36-0) is a metal (semi-metal) of silver-white color with a bluish tint, coarse-grained structure. There are four metallic allotropic modifications of antimony that exist at different pressures, and three amorphous modifications.

Historical reference

Antimony has been known since ancient times. In the countries of the East, it was used approximately 3000 BC. e. for making vessels. In ancient Egypt already in the 19th century. BC e. antimony glitter powder (natural Sb 2 S 3) called mesten or stem used for blackening the eyebrows. In ancient Greece it was known as stimi And stibi, hence Latin stibium. About 12-14 centuries. n. e. the name appeared antimonium. In 1789 A. Lavoisier included antimony in the list of chemical elements under the name antimoine(Modern English antimony, Spanish and Italian antimonio, German Antimon). Russian "antimony" comes from Turkish surme; he designated the powder of the lead luster PbS, which also served to blacken the eyebrows (according to other sources, “antimony” - from the Persian “surmium” - metal). A detailed description of the properties and methods for obtaining antimony and its compounds was first given by the alchemist Vasily Valentin (Germany) in 1604.

Being in nature

In medium-temperature hydrothermal veins with ores of silver, cobalt and nickel, also in sulfide ores of complex composition.

Isotopes of antimony

Natural antimony is a mixture of two isotopes: 121 Sb (isotope abundance 57.36%) and 123 Sb (42.64%). The only long-lived radionuclide is 125 Sb with a half-life of 2.76 years, all other isotopes and isomers of antimony have a half-life not exceeding two months, which does not allow them to be used in nuclear weapons.

Threshold energy for reactions with neutron release (1st):
121 Sb - 9.248 MeV
123 Sb - 8.977 MeV
125 Sb - 8.730 MeV

Physical and chemical properties

Antimony in the free state forms silvery-white crystals with a metallic sheen, density 6.68 g/cm³. Resembling a metal in appearance, crystalline antimony is more brittle and less thermally and electrically conductive.

Application

Antimony is increasingly used in the semiconductor industry in the production of diodes, infrared detectors, and Hall effect devices. In the form of an alloy, this metalloid significantly increases the hardness and mechanical strength of lead.
Used:

- batteries
- anti-friction alloys
– printing alloys
- small arms and tracer bullets
— cable sheaths
- matches
- drugs, antiprotozoal drugs
– soldering individual lead-free solders contain 5% Sb
– use in linotype printing machines

Antimony compounds in the form of oxides, sulfides, sodium antimonate and antimony trichloride are used in the production of refractory compounds, ceramic enamels, glass, paints and ceramic products. Antimony trioxide is the most important of the antimony compounds and is mainly used in flame retardant compositions. Antimony sulfide is one of the ingredients in match heads.

The natural sulfide of antimony, stibnite, was used in biblical times in medicine and cosmetics. Stibnite is still used in some developing countries as a medicine. Antimony compounds - meglumine antimoniate (glucantim) and sodium stibogluconate (pentostam), are used in the treatment of leishmaniasis.

Physical properties

Ordinary antimony it is a silvery-white metal with a strong luster. Unlike most other metals, it expands when solidified. Sb lowers the melting and crystallization points of lead, and the alloy itself expands somewhat in volume during hardening. Together with tin and copper, antimony forms a metal alloy - Babbit, which has antifriction properties (use in bearings). Sb is also added to metals intended for thin castings.

Red mercury." The peculiarity of this substance is that it is a kind of multifunctional nuclear catalyst (neutron multiplication factor 7-9) and should be very strictly taken into account by any country in view of the threat of nuclear terrorism.

Prices

Prices for metallic antimony in ingots with a purity of 99% amounted to about 5.5 USD/kg.

Thermoelectric materials

Antimony telluride is used as a component of thermoelectric alloys (thermo-emf with 100-150 μV/K) with bismuth telluride.

Biological role and effects on the body

Antimony is a micronutrient. Its content in the human body is 10 -6% by weight. Constantly present in living organisms, the physiological and biochemical role has not been elucidated. Antimony exhibits an irritating and cumulative effect. Accumulates in the thyroid gland, inhibits its function and causes endemic goiter. However, getting into the digestive tract, antimony compounds do not cause poisoning, since Sb (III) salts are hydrolyzed there with the formation of poorly soluble products. At the same time, antimony (III) compounds are more toxic than antimony (V). Dust and vapors of Sb cause nosebleeds, antimony "casting fever", pneumosclerosis, affect the skin, and disrupt sexual functions. The taste perception threshold in water is 0.5 mg/l. The lethal dose for an adult is 100 mg, for children - 49 mg. For antimony aerosols MPC in the air of the working area is 0.5 mg/m 3 , in the atmospheric air 0.01 mg/m 3 . MPC in soil 4.5 mg/kg. In drinking water, antimony belongs to hazard class 2, has a MPC of 0.005 mg / l, established according to the sanitary and toxicological LPV. In natural waters, the content standard is 0.05 mg/l. In industrial waste water discharged to treatment facilities with biofilters, the content of antimony should not exceed 0.2 mg/l.

Antimony is a poisonous metal (semimetal),
used in metallurgy, medicine and technology
Toxic and poisonous stones and minerals

Antimony (Latin Stibium, denoted by the symbol Sb) is an element with atomic number 51 and atomic weight 121.75. It is an element of the main subgroup of the fifth group, the fifth period of the periodic system of chemical elements D.I. Mendeleev. Antimony is a metal (semi-metal) of silver-white color with a bluish tint, coarse-grained structure. In its usual form, it forms crystals with a metallic luster and a density of 6.68 g/cm3.

Resembling metal in appearance, crystalline antimony is brittle and conducts heat and electric current worse than ordinary metals. Two stable isotopes 121Sb (isotopic abundance 57.25%) and 123Sb (42.75%) are known in nature. In the photo - Antimony. Tulare County California. USA. Photo: A.A. Evseev.

Humanity has been familiar with antimony since ancient times: in the countries of the East, it was used approximately 3000 BC. e. for making vessels. An antimony compound - antimony gloss (natural Sb2S3) was used for dyeing black eyebrows and eyelashes. In ancient Egypt, the powder from this mineral was called mesten or stem, for the ancient Greeks, antimony was known as stími and stíbi, hence the Latin stibium.

Metallic antimony is rarely used due to its brittleness, however, due to the fact that it increases the hardness of other metals (tin, lead) and does not oxidize under normal conditions, metallurgists often introduce it as an alloying element into various alloys. Alloys using the fifty-first element are widely used in a wide variety of areas: for battery plates, typographic fonts, bearings (babbits), screens for working with sources of ionizing radiation, dishes, art casting, etc.

Pure metallic antimony is mainly used in the semiconductor industry - to obtain antimonides (antimony salts) with semiconductor properties. Antimony is a part of medicinal synthetic preparations. Antimony compounds are also widely used: antimony sulfides are used in the manufacture of matches and in the rubber industry. Antimony oxides are used in the production of refractory compounds, ceramic enamels, glass, paints and ceramic products.

Antimony belongs to trace elements (the content in the human body is 10–6% by weight). It is known that antimony forms bonds with sulfur atoms, which causes its high toxicity. Antimony exhibits an irritating and cumulative effect, accumulates in the thyroid gland, inhibiting its function and causing endemic goiter. Dust and vapors cause nosebleeds, antimony "casting fever", pneumosclerosis, affect the skin, disrupt sexual functions. Nevertheless, antimony compounds have been used in medicine since ancient times as valuable medicines.

Biological properties

Antimony is a microelement found in many living organisms. It has been established that the content of the fifty-first element (per hundred grams of dry matter) is 0.006 mg in plants, 0.02 mg in marine animals, and 0.0006 mg in terrestrial animals. In the human body, the content of antimony is only 10-6% by weight. The intake of the fifty-first element into the body of animals and humans occurs through the respiratory organs (with inhaled air) or the gastrointestinal tract (with food, water, medicines), the average daily intake is about 50 mcg. The main antimony accumulation depots are thyroid, liver, spleen, kidneys, bone tissue, accumulation also occurs in the blood (in erythrocytes, antimony accumulates mainly in the oxidation state +3, in the blood plasma - in the oxidation state +5).

The metal is excreted from the body quite slowly, mainly with urine (80%), in small amounts - with faeces. However, the physiological and biochemical role of antimony is still unknown and poorly understood, so there are no data on the clinical manifestations of antimony deficiency.

However, data on the maximum permissible concentrations of the element for the human body are known: 10-5-10-7 grams per 100 grams of dry tissue. At a higher concentration, antimony inactivates (interferes with work) a number of enzymes of lipid, carbohydrate and protein metabolism (possibly as a result of blocking sulfhydryl groups).

The fact is that antimony and its derivatives are toxic - Sb forms bonds with sulfur (for example, it reacts with SH-groups of enzymes), which causes its high toxicity. Accumulating in excess in the thyroid gland, antimony inhibits its function and causes endemic goiter. When it enters the digestive tract, antimony and its compounds do not cause poisoning, since Sb (III) salts are hydrolyzed to form poorly soluble products that are excreted from the body: irritation of the gastric mucosa is observed, reflex vomiting occurs, and almost the entire amount of antimony taken is thrown out along with emetic masses.

However, after taking significant amounts of antimony or with prolonged use, lesions of the gastrointestinal tract can be observed: ulcers, hyperemia, swelling of the mucosa. Antimony (III) compounds are more toxic than antimony (V) - they are bioavailable. The taste perception threshold in water is 0.5 mg/l. The lethal dose for an adult is 100 mg, for children - 49 mg. MPC Sb in soil 4.5 mg/kg.

In water, antimony belongs to the second hazard class, has a MPC of 0.005 mg/l, established according to the sanitary-toxicological LPV. In natural waters, the standard is 0.05 mg/l. In industrial waste water discharged to treatment facilities with biofilters, the content of antimony should not exceed 0.2 mg/l.

Dust and vapors cause nosebleeds, antimony "casting fever", pneumosclerosis, affect the skin, disrupt sexual functions. For antimony aerosols MPC in the air of the working area is 0.5 mg/m3, in the atmospheric air 0.01 mg/m3. When rubbed into the skin, antimony causes irritation, erythema, pustules, similar to smallpox.

This kind of damage can be observed in professions dealing with antimony: enamellers (using antimony oxide), printers (working with printed alloys, British metal). In case of chronic intoxication of the body with antimony, it is necessary to take preventive measures, limit its intake, carry out symptomatic treatment, it is possible to use complexing agents.

Nevertheless, despite the negative factors associated with the toxicity of antimony, it, like its compounds, is used in medicine. Even in the XV-XVI centuries. antimony preparations were used as medicines, mainly as expectorants and emetics. To induce vomiting, the patient was given wine aged in an antimony vessel. One of the antimony compounds, KC4H4O6 (SbO) * H2O, is called an emetic stone. The mechanism of action of such a drug is described by us above.

Antimony. Monarch district (Sb), Gravelotte, Limpopo prov. South Africa. Photo: A.A. Evseev.

Interesting Facts

One of the most modern methods of "using" antimony has entered the arsenal of criminologists. The fact is that a rifle bullet leaves behind a (tracer) vortex flow - a "trace" in which there are shares of a number of elements - lead, antimony, barium, copper. As they settle, they leave an invisible "imprint" on the surface.

However, these particles were invisible only until recently, modern developments make it possible to determine the presence of particles and the direction of the bullet's flight. This happens as follows: strips of wet filter paper are placed on the surface, then they are placed in an elementary particle accelerator (synchrophasotron) and bombarded with neutrons. As a result of the “shelling”, some of the atoms transferred to the paper (including antimony atoms) are converted into unstable radioactive isotopes, and the degree of their activity makes it possible to judge the content of these elements in the samples and thus determine the trajectory and length of the bullet flight, the characteristics of the bullet, weapons and ammunition.

Many semiconductor materials containing antimony have been obtained under weightless conditions aboard the Salyut-6 and Skylab near-Earth space orbital scientific stations.

The author of "The Adventures of the Good Soldier Schweik" in the story "The Stone of Life" sets out one of the versions of the origin of the name "antimony". In 1460, the abbot of the Stahlhausen monastery in Bavaria, the father of one monastery, was looking for a philosopher's stone (an amalgam of gold and ruti - "white gold", evaporated to gold). In those distant times, it would hardly have been possible to find at least one monastery in whose cells and cellars alchemical work would not have been going on (Spain, the city of Almaden, the world's largest deposit of industrial red cinnabar - mercury sulfide, a satellite of antimony deposits, dry volcanic sublimation on red-hot batholiths). In the photo below - deposits of the "cinnabar" type and cinnabar - a companion of antimony in the deposits.

Black antimonite - antimony sulfide, with satellites - gray chalcedony
and red cinnabar in a druse, Nikitovka, Donetsk region, south-east of Ukraine

In one of the experiments, the abbot mixed the ashes of Jeanne D "Arc ("Orleans Virgin" - the pride of France) in a crucible with ashes and double the amount of earth taken from the place of burning (cinnabar). The monk began to heat this "hellish mixture". After evaporation with coal it turned out to be a heavy dark substance with a metallic sheen (mercury).The result upset the abbot - the book said that the cherished "philosopher's stone" should be weightless and transparent (translation errors - expensive and golden in color).

Disillusioned with the "heretical science", Leonardus threw the resulting substance into the monastery courtyard (with cinders - antimonite). Soon he noticed that the pigs willingly lick the "stone" (cinder) thrown by him and quickly grow fat. Deciding that he had discovered a nutrient that could feed the hungry, the monk prepared a new portion of the "stone of life", crushed it and added this powder to the porridge that his skinny brothers in Christ ate. The next day forty monks of the monastery died in terrible agony. Repenting of his deed, the abbot cursed the experiments, and renamed the "stone of life" antimonium, that is, a remedy "against the monks." It is not worth vouching for the authenticity of the story, just as for the author of this version.

Chemists of the Middle Ages in Western Europe (Spain) found that almost all metals often dissolve in molten antimony (the element of the "philosopher's stone-II" - after mercury and its amalgams). Antimony - a metal that devours other metals - is a "chemical predator". Perhaps, such reasoning led to the symbolic image of antimony in the form of a figure of a wolf with an open (open) mouth (burns of the chemical production of antimony - "Hell's or Devil's mouths" in Almaden, Spain, the Catholic Church of His Majesty the King of Spain).

In Arabic literature, lead and antimony shine was called al-kahkhal (make-up), alko (g) ol, alkofol. It was believed that cosmetic and therapeutic products for the eyes contain a mysterious spirit (genie), hence, probably, volatile liquids began to be called alcohol.

Everyone is familiar with the expression "antimony eyebrows" (make-up on the face), which previously denoted a cosmetic operation using antimony sulfide powder Sb2S3. The fact is that antimony compounds have different colors: some are black, others are orange-red. Even in time immemorial, the Arabs traded in the countries of the East eyebrow paint, which included antimony. The author of the novel "Samvel" describes in detail the technique of this cosmetic operation: "The young man took out a leather bag from his bosom, took a thin pointed golden stick, brought it to his lips, breathed on it so that it became wet, and lowered it into powder. The stick was covered with a thin layer black dust. He began to put kohl on his eyes." During archaeological excavations of ancient burials in the territory of Armenia, all the above-described cosmetic accessories were found: a thin pointed gold stick and a tiny box made of polished marble (theft at Vake in Spain, Middle Ages, Western Europe).

Story

The name of the discoverer of antimony is unknown, since this metal has been known to man since prehistoric times. Products from antimony and its alloys (in particular, antimony with copper) have been used by man for many millennia, antimony bronze, used during the Babylonian kingdom, consisted of copper and additives of tin, lead and antimony. Archaeological finds have confirmed the assumption that in Babylon as early as 3 thousand years BC. (together with its geological companion - red cinnabar) vessels were made from antimony, for example, the description of fragments of a vase from metal antimony found in Tello (southern Babylonia) is well known. Other objects made of antimony were also found, in particular in Georgia, dating back to the 1st millennium BC. e. Antimony alloys with lead were also used for the manufacture of products, and it should be noted that in ancient times, metallic antimony was not considered an independent metal, and it was mistaken for lead (an imitator of a transitional chemical production form of mercury - an aphrodisiac for women).

With regard to antimony compounds, the most famous "antimony luster" - antimony sulfide Sb2S3, which was known in many countries. In India, Mesopotamia, Egypt, Central Asia and other Asian countries, a thin shiny black powder was made from this mineral, which was used for cosmetic purposes, especially for making up the eyes "eye ointment". Pliny the Elder calls antimony stimmi and stibi - cosmetic and pharmaceutical products for make-up and eye treatment. In the Greek literature of the Alexandrian period, these words mean a black cosmetic (black powder).

As for the Russian word "antimony", then, most likely, it is of Turkic origin - surme. The original meaning of this term was - ointment, makeup, ointment. This is confirmed by the preservation of this word to our time in many oriental languages: Turkish, Persian, Uzbek, Azerbaijani and others. According to other sources, "antimony" comes from the Persian "surme" - metal. In Russian literature of the early 19th century, the words antimony (Zakharov, 1810), surma, surma, surum beetle and antimony are used.

Being in nature

Despite the fact that the content of antimony in the earth's crust is relatively low - the average content (clarke) 5∙10-5% (500 mg / t) - it was known in ancient times. This is not surprising, because antimony is part of about a hundred minerals, the most common of which is the antimony luster Sb2S3 - a lead-gray mineral with a metallic luster (aka antimonite, aka stibnite), containing more than 70% antimony and serving as the main industrial raw material for receiving it. The bulk of the antimony sheen is formed in hydrothermal deposits, where its accumulations create deposits of antimony ore in the form of veins and bodies of a sheet-like shape. In the upper parts of the ore bodies, near the surface of the earth, the antimony sheen undergoes oxidation, forming a number of minerals, namely: senarmontite and valentite Sb2O3 (both minerals of the same chemical composition, contain 83.32% antimony and 16.68% oxygen); serving (antimony ocher) Sb2O4; stibiocanite Sb2O4 nH2O; cermesite Sb2S2O. In rare cases, antimony ores (due to their affinity with sulfur) are represented by complex sulfides of antimony, copper, mercury, lead, iron (berthierite FeSbS4, jamsonite Pb4FeSb6S14, tetrahedrite Cu12Sb4S13, livingstonite HgSb4S8 and others), as well as oxides and oxychlorides (senarmontite, nodrite PbClSbO 2) antimony.

The content of antimony in igneous effusive rocks is lower than in sedimentary rocks (volcanic sublimation along cracks from hot magma on a catalyst from the caldera - water). In sedimentary, the highest concentrations of antimony are observed in clay shales (1.2 g/t), bauxites and phosphorites (2 g/t) and the lowest in limestones and sandstones (0.3 g/t). Elevated amounts of antimony are found in coal ash (it conflicts with cinnabar with water - cinnabar is formed on arsenic).

In natural compounds, antimony, on the one hand, exhibits the properties of a metal and is a typical chalcophile element, forming antimonite. At the same time, antimony has the properties of a metalloid, manifested in the formation of various sulfosalts - boulangerite, tetrahedrite, burnonite, pyrargyrite and others. With a number of metals (palladium, arsenic), antimony is capable of creating intermetallic compounds. In addition, isomorphic substitution of antimony and arsenic in fahlore and geocronite Pb5(Sb, As)2S8 and antimony and bismuth in cobellite Pb6FeBi4Sb2S16 and others is observed in nature.

It should be noted that antimony is also found in its native state. Native antimony is a mineral of composition Sb, sometimes with a slight admixture of silver, arsenic, bismuth (up to 5%). It occurs in the form of granular masses (crystallizing in the trigonal system), sinter formations and rhombohedral lamellar crystals.

Native antimony has a metallic luster, tin-white color with a yellow tint. It is formed with a deficiency of sulfur in low-temperature antimony, antimony-gold-silver and copper-lead-zinc-antimony-silver-arsenic, as well as high-temperature pneumatolytic-hydrothermal antimony-silver-tungsten deposits (in the latter, the content of antimony can reach crystalline values ​​- Seinäjoki in Finland - a crystalline shield of antimony).

The content of antimony in stratal ore bodies is from 1 to 10%, in vein - from 3 to 50%, the average content is from 5 to 20%, sometimes more. Stratified ore bodies are formed by means of low-temperature hydrothermal solutions by filling cracks in rocks, as well as by replacing the latter with antimony minerals. Two types of deposits are of major commercial importance: reservoir bodies, lenses, pockets and stockworks in mature mantle-like deposits formed as a result of metasomatic replacement of limestones under the shale screen by silica and antimony compounds (in China - Sikuanshan; Asia). The second type of deposits is a system of steeply dipping secant quartz-antimonite veins in shales (in the CIS - Turgayskoye, Razdolninskoye, Sarylakh, etc.; in South Africa - Gravelot, etc.). Third - vertical cracks (Donetsk region, south-east of Ukraine, Nikitovka). Rich deposits of antimony minerals have been found in China, Bolivia, Japan, the USA, Mexico, and a number of African countries.

Application

Due to its brittleness, metallic antimony is rarely used, but since it increases the hardness of other metals (for example, tin and lead) and does not oxidize under normal conditions, metallurgists introduce it into the composition of various alloys. The total number of alloys containing the fifty-first element approaches two hundred. The alloying of a number of alloys with antimony was known back in the Middle Ages: “If a certain portion of antimony is added to tin by alloying, a printing alloy is obtained ( garth) from which the font used by those who receive the books is made."

Incredibly, such an alloy - garth(from Ukrainian - " hardening", - antimony, tin and lead), containing from 5 to 30% Sb - an indispensable attribute of a printing house! What is the uniqueness of the alloy that has passed through the centuries? Molten antimony, unlike other metals (except bismuth and gallium), expands upon solidification , increases its volume.Thus, when casting a font, the printing alloy containing antimony, solidifying in the casting matrix, expands, due to which it fills it tightly and reproduces a mirror image, which is transferred to paper.In addition, antimony gives the printing alloy hardness and wear resistance, which is important when reusing a template (matrix, typographical form).

Lead-antimony alloys used in chemical engineering (for lining bathtubs and other acid-resistant equipment) have high hardness and corrosion resistance. The most well-known gartble alloy (Sb content from 5 to 15%) is used for the manufacture of pipes through which aggressive liquids are transported. Sheaths of telegraph, telephone and electric cables, electrodes, battery plates, bullet cores, shot, shrapnel are made from the same alloy. Bearing alloys (babbits) containing tin, copper, lead and antimony (Sb from 4 to 15%) have found wide application (machine tool building, railway and road transport), they have sufficient hardness, high abrasion resistance, high corrosion resistance. Antimony is also added to metals intended for thin and brittle castings.

Pure antimony is used to obtain antimonides (AlSb, CaSb, InSb), as well as an additive in the production of semiconductor compounds. Such antimony is alloyed (only 0.000001%) with the most important semiconductor metal - germanium, in order to improve its quality. A number of its compounds (in particular, with gallium and indium) are semiconductors. Antimony is used in the semiconductor industry not only as legends. Antimony is also used in the production of diodes (AlSb and CaSb), infrared detectors, and Hall effect devices. Indium antimonide is used to build Hall sensors, to convert non-electric quantities into electrical ones, in calculating devices, as a filter and an infrared radiation recorder. Due to the large band gap, AlSb is used to build solar cells.

Diverse "activity" and antimony compounds. For example, antimony trioxide (Sb2O3) is mainly used as a pigment for paints, an opacifier for enamel, a mordant in the textile industry, in the production of refractory compounds and paints, it is also used for the manufacture of optical (enlightened) glass, ceramic enamels.

Antimony pentoxide (Sb2O5) is widely used in the manufacture of pharmaceuticals, in the production of glass, ceramics, paints, in the textile and rubber industries, as an integral part of fluorescent fluorescent lamps (Sb is activated in fluorescent lamps with calcium halophosphate). Trisulphuric antimony is used in the production of matches and in pyrotechnics. Pyatiserine antimony is used to vulcanize rubber (for "medical" rubber, which includes Sb2S5, a characteristic red color and high elasticity). Antimony trichloride (SbCl3) is used for bluing steels, blackening zinc, in medicine, as a mordant in textile production, and as a reagent in analytical chemistry.

Toxic stibine or hydrogen antimony SbH3 is used as a fumigant to control insect pests of agricultural plants. Many antimony compounds can serve as pigments in paints, for example, potassium antimony (K2O * 2Sb2O5) is widely used in the manufacture of ceramics, antimony paint, which is based on antimony trioxide, is used to paint the underwater part and superstructures of ships. Metaantimony sodium (NaSbO3) called "leuconine" is used to coat kitchen utensils, as well as in the production of enamel and milky white glass.

Production

Antimony is a rather rare element, its content in the earth's crust is no more than 5∙10-5%, however, over a hundred minerals containing this element are known. A common and semi-industrial antimony mineral (not sulfide) is antimony luster, or stibnite, Sb2S3, containing over 70% antimony. The remaining antimony ores differ sharply from each other in their metal content - from 1 to 60%. It is impractical to obtain metallic antimony from ores containing less than 10% Sb. For this reason, poor ores are enriched.

Sulfide (the richest), as well as complex ores, are enriched by flotation, and sulfide-oxidized - by combined methods. After enrichment, the ore concentrate contains from 30 to 60% Sb, such raw materials are suitable for processing into antimony, which is produced by pyrometallurgical or hydrometallurgical methods. In the first variant, transformations take place in the melt under the influence of high temperature, in the second - in aqueous solutions of antimony compounds and other elements. Pyrometallurgical methods for obtaining antimony include: precipitation, reduction and direct smelting in shaft furnaces. Precipitation melting, the raw material for which is a sulfide concentrate, is based on the displacement of antimony from its sulfide by iron:

Sb2S3 + 3Fe → 2Sb + 3FeS

The process takes place in reverberatory or rotary drum furnaces as follows: iron in the form of cast iron or steel chips is introduced directly into the furnace, then to form a reducing atmosphere that prevents losses with the release of volatile antimony (III) oxide, charcoal (coal fines or coke). Fluxes - sodium sulfate or soda - are introduced into the charge for slagging of waste rock. The melting of the charge takes place at a constant temperature of 1300-1400 o C. As a result of precipitation melting, crude antimony is formed, containing from 95 to 97% Sb (depending on the initial content in the concentrate) and from 3 to 5% impurities - iron, gold, lead , copper, arsenic and other metals that were contained in the feedstock. The extraction of antimony from the original concentrate ranges from 77 to 92%.

Reduction melting is based on the reduction of antimony oxides to metal with solid carbon:

Sb2O4 + 4C → 2Sb + 4CO

It is produced in reverberatory or short drum furnaces at a temperature of 800-1000 o C. The charge is oxidized ore, charcoal (coal dust is possible) and flux (soda, potash). It turns out crude antimony is more pure than during precipitation melting (more than 99% Sb), the extraction of metal from the concentrate is 80-90%.

Direct smelting in shaft furnaces is used to smelt metal from oxidized or sulfide lumpy raw materials. The maximum temperature of 1 300-1 500 o C is achieved by burning coke - an integral part of the charge, limestone, pyrite cinders or iron ore act as a flux. The metal is obtained both due to the reduction of carbon (coal) with Sb2O3 coke, and as a result of the interaction of non-oxidized antimonite with Sb2O3 with the constant removal of SO2 from the melt by furnace gases. The smelting products (rough metal and slag) drain into the lower part of the furnace and are discharged from it into a sump.

Another method of obtaining antimony - hydrometallurgical is increasingly used in recent years. It consists of two stages: the processing of raw materials with the transfer of antimony compounds into a solution and the isolation of antimony from these solutions. The complexity of the method lies in the fact that it is problematic to transfer antimony into solution: most of the natural antimony compounds do not dissolve in water. However, the desired solvent was found - an aqueous solution of sodium sulfide (120 g/l) and caustic soda (30 g/l). Sulfide and antimony oxide goes into solution in the form of sulfasalts and salts of antimony acids. From the resulting solution, antimony is isolated by electrolysis. Rough antimony, obtained by the hydrometallurgical method, is not distinguished by purity and contains from 1.5 to 15% impurities.

To obtain antimony with fewer impurities, pyrometallurgical (fire) or electrolytic refining is used. The most common fire refining in industry is carried out in reverberatory furnaces. When stibnite is added to the molten draft antimony, iron and copper impurities form sulfur compounds and turn into matte. Arsenic is removed in the form of sodium arsenate by melting in an oxidizing atmosphere (air purge) with soda or potash, and sulfur is also removed.

In the presence of noble metals, anodic electrolytic refining is used, which makes it possible to concentrate noble metals in the sludge. Refined antimony contains no more than 0.5-0.8% of foreign impurities. However, even such a metal does not satisfy all consumers - for the semiconductor industry, for example, antimony of 99.999% purity is required. In this case, a crystal-physical cleaning method is used - zone melting in an argon atmosphere, in especially critical cases, zone melting is repeated several times.

Physical properties

Antimony is known in crystalline form and three amorphous modifications (explosive, black and yellow). In appearance, crystalline, or gray, antimony (its main modification) is a shiny silver-white metal with a bluish tint, which is thinner, the more impurities (a pure element in a free state forms needle-shaped crystals resembling the shape of stars).

Many mechanical properties depend on the purity of the metal. Gray antimony crystallizes in a trigonal (rhombohedral) system (a = 0.45064 nm, z = 2, space group R3m), its density is 6.61-6.73 g/cm3 (in the liquid state - 6.55 g/cm3) . At a pressure of ~5.5 GPa, the rhombohedral lattice of gray antimony transforms into the cubic modification SbII. At a pressure of 8.5 GPa - into hexagonal SbIII. Above 28 GPa, SbIV is formed. Crystalline antimony melts at a low temperature - 630.5 o C, molten antimony begins to boil at 1634 o C.

The specific heat capacity of antimony at temperatures of 20-100 o C is 0.210 kJ / (kg * K) or 0.0498 cal / (g * o C), thermal conductivity at 20 o C is 17.6 W / (m * K) or 0.042 cal / (cm * sec * o C). Temperature coefficient of linear expansion for polycrystalline antimony 11.5 * 10-6 at temperatures from 0 to 100 o C; for a single crystal a1 = 8.1 * 10-6, a2 = 19.5 * 10-6 at 0-400 o C, electrical resistivity at 20 o C is 43.045 * 10-6 cm * cm.

Antimony is diamagnetic, its specific magnetic susceptibility is -0.66 * 10-6. Brinell hardness for cast metal is 325-340 MN/m2 (32.5-34.0 kgf/mm2); modulus of elasticity 285-300; ultimate strength 86.0 MN/m2 (8.6 kgf/mm2). The transition temperature of antimony to the superconducting state is 2.7 K. Gray antimony has a layered structure, where each Sb atom is pyramidally bonded to three neighbors in a layer (interatomic distance 0.288 nm) and has three nearest neighbors in another layer (interatomic distance 0.338 nm). Under normal conditions, it is this form of antimony that is stable.

With a sharp cooling of gray antimony vapors, black antimony is formed (density 5.3 g/cm3), which, when heated to 400 o C without air, passes into gray antimony. Black antimony has semiconductor properties. Yellow antimony is formed by the action of oxygen on liquid stibine SbH3 and contains minor amounts of chemically bound hydrogen. When heated, as well as when illuminated with visible light, yellow antimony turns into black antimony.

Explosive antimony looks like graphite (density 5.64-5.97 g/cm3) and explodes on impact and friction. This modification is formed during the electrolysis of a solution of SbCl3 in hydrochloric acid at a low current density and contains bound chlorine. Explosive antimony, when rubbed or hit with an explosion, turns into metallic antimony.

It is impossible to state unequivocally that antimony is a metal. Even medieval alchemists ranked it (however, like some true metals: zinc and bismuth, for example) to the group of "semimetals", because they were worse forged, and malleability was considered the main feature of the metal, in addition, according to alchemical ideas, each metal was associated with some celestial body. By that time, all known celestial bodies had already been distributed (the Sun was associated with gold, the Moon personified silver, Mercury - mercury, Venus - copper, Mars - iron, Jupiter - tin and Saturn - lead), therefore, independent metals, according to alchemists, no longer existed.

Unlike most metals, antimony, firstly, is brittle and grinds into powder (this can be done in a porcelain mortar with a porcelain pestle), and secondly, it conducts electricity and heat worse (at 0 o C, its electrical conductivity is only 3.76 % electrical conductivity of silver). At the same time, crystalline antimony has a characteristic metallic luster, above 310 o C it becomes plastic, in addition, high-purity single crystals are plastic. With sulfuric acid, antimony forms sulfate Sb2 (SO4) 3 and asserts itself as a metal, and nitric acid oxidizes antimony to a higher oxide, which is formed in the form of a hydrated compound xSb2O5 * yH2O, proving its character as a non-metal. It turns out that the metallic properties of antimony are rather weakly expressed, however, the properties of a non-metal are far from being fully inherent in it.

Chemical properties

The configuration of the outer electrons of the antimony atom is 5s25p3. In compounds, antimony is similar to arsenic, but differs from it in pronounced metallic properties, and exhibits oxidation states of +5, +3 and -3. In chemical terms, the fifty-first element is inactive - in air at room temperature, metallic antimony is stable, it begins to oxidize at temperatures close to the melting point (~ 600 o C) with the formation of antimony (III) oxide, or antimony anhydride - Sb2O3:

4Sb + 3O2 → 2Sb2O3

above the melting point, antimony ignites. Antimony (III) oxide is an amphoteric oxide with a predominance of basic properties, insoluble, forms minerals. It reacts with alkalis and acids, and in strong acids, such as sulfuric and hydrochloric, antimony (III) oxide dissolves to form antimony (III) salts, in alkalis to form salts of antimony H3SbO3 or metaantimony HSbO2 acid:

Sb2O3 + 2NaOH → 2NaSbO2 + H2O

Sb2O3 + 6HCl → 2SbCl3 + 3H2O

When Sb2O3 is heated above 700 o C in oxygen, an oxide of the composition Sb2O4 is formed:

2Sb2O3 + O2 → 2Sb2O4

Sb2O4 simultaneously contains tri- and pentavalent antimony. In its structure, octahedral groups and are connected to each other. This antimony oxide is the most stable.

Crushed powdered antimony burns in an atmosphere of chlorine, the fifty-first element actively reacts with other halogens, forming antimony halides. Metallic antimony does not react with nitrogen and hydrogen, just as with silicon and boron, carbon slightly dissolves in molten antimony. With sulfur, phosphorus, arsenic and with many metals, antimony combines during fusion. Combining with metals, antimony forms antimonides, for example, tin antimonide SnSb, nickel Ni2Sb3, NiSb, Ni5Sb2 and Ni4Sb. Antimonides can be considered as products of substitution of hydrogen in stibine (SbH3) by metal atoms. Some antimonides, in particular AlSb, GaSb, InSb, have semiconductor properties.

Antimony is resistant to water and dilute acids. For example, antimony does not dissolve in hydrochloric acid and dilute sulfuric acid. It does not react with hydrofluoric and hydrofluoric acids. However, concentrated hydrochloric and sulfuric acids slowly dissolve antimony with the formation of chloride SbCl3 and sulfate Sb2(SO4)3. Poorly soluble β-antimony acid HSbO3 is formed with concentrated nitric acid:

3Sb + 5HNO3 → 3HSbO3 + 5NO + H2O

Antimony dissolves in aqua regia - in a mixture of nitric and tartaric acids. Solutions of alkalis and NH3 do not act on antimony, molten alkalis dissolve antimony with the formation of antimony.

When heated with alkali metal nitrates or chlorates, powdered antimony forms salts of antimony acid with a flash. Of practical interest are sparingly soluble salts of antimony acid - antimonates (MeSbO3 * 3H2O, where Me is Na, K) and salts of non-isolated metaantimonous acid - metaantimonites (MeSbO2 * 3H2O), which have reducing properties. Antimonates (III) of alkali metals, especially potassium, are soluble in water, unlike other antimonates.

When heated in air, they oxidize to antimonates (V). Known are metaantimonates (III), for example, KSbO2, orthoantimonates (III), like Na3SbO3, and polyantimonates, for example, NaSb5O8, Na2Sb4O7. Rare earth elements are characterized by the formation of orthoantimonates LnSbO3 and Ln3Sb5O12. Antimonates of nickel, manganese - catalysts in organic synthesis (oxidation and polycondensation reactions), antimonates of rare earth elements - phosphors.

Of the important compounds of antimony, in addition to oxide (III), the following are also isolated: hydride (stibine) SbH3 - a colorless toxic gas formed by the action of HCl on magnesium or zinc antimonides or hydrochloric acid solution of SbCl3 on NaBH4. Stibine slowly decomposes at room temperature into antimony and hydrogen, the process is significantly accelerated when heated to 150 o C; it oxidizes, burns in air; slightly soluble in water; used to obtain high purity antimony. Another important compound of the fifty-first element, antimony(V) oxide or antimony anhydride, Sb2O5 (yellow crystals, dissolves in water to form antimony acid) is primarily acidic.

Interestingly, the lower oxide of antimony (Sb2O3) is called antimony anhydride, although this statement is incorrect, because anhydride is an acid-forming oxide, and in Sb (OH) 3, Sb2O3 hydrate, basic properties clearly predominate over acidic ones. Thus, the properties of the lower oxide of antimony indicate that antimony is a metal. However, the highest oxide of antimony Sb2O5 is indeed an anhydride with pronounced acidic properties, which speaks in favor of the fact that antimony is still a non-metal. It turns out that the dualism observed in the physical characteristics of antimony is also traced in its chemical properties of antimony.

Antimonite. County of White Caps Mine Nevada, USA. Photo: A.A. Evseev.

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Name of especially dangerous cargo during transportation	Number UN	Class ADR
ANTIMONY POWDER	2871	6.1
Antimony Pentafluoride Antimony Pentafluoride	1732	8
ANTIMONY LACTATE	1550	6.1
ANTIMONY PENTAFLUORIDE	1732	8
ANTIMONY PENTACHLORIDE, LIQUID	1730	8
ANTIMONY PENTACHLORIDE SOLUTION	1731	8
ANTIMONY COMPOUND, INORGANIC, LIQUID, N.C.C.	3141	6.1
ANTIMONY COMPOUND, INORGANIC, SOLID, N.C.K.	1549	6.1
ANTIMONY TRICHLORIDE, SOLID	1733	8
ANTIMONY-POTASSIUM TARTRATE	1551	6.1

Antimony (lat. Stibium; denoted by the symbol Sb) - an element of the main subgroup of the fifth group of the fifth period of the periodic system of chemical elements of D. I. Mendeleev, atomic number 51.

Atomic mass - 121.76

Density, kg/m³ - 6620

Melting point, ° С - 630.5

Heat capacity, kJ / (kg ° С) - 0.205

Electronegativity - 1.9

Covalent radius, Å - 1.40

1st ionization potential, ev - 8.64

Historical information about antimony

Along with gold, mercury, copper and six other elements, antimony is thought to be prehistoric. The name of its discoverer has not come down to us. It is only known that, for example, in Babylon as early as 3 thousand years BC. vessels were made from it. The Latin name for the element "stibium" is found in the writings of Pliny the Elder. However, the Greek "στιβι", from which this name comes, originally referred not to antimony itself, but to its most common mineral, antimony luster.

In the countries of ancient Europe, only this mineral was known. In the middle of the century, they learned to smelt “antimony kinglet” from it, which was considered a semi-metal. Agricola (1494...1555), the largest metallurgist of the Middle Ages, wrote: “If a certain portion of antimony is added to lead by alloying, a typographical alloy is obtained, from which a type is made, used by those who print books.” Thus, one of the main current uses of element #51 is many centuries old.

The properties and methods of obtaining antimony, its preparations and alloys for the first time in Europe are described in detail in the well-known book "The Triumphal Chariot of Antimony", published in 1604. For many years, the Benedictine alchemist Vasily Valentin, who allegedly lived at the beginning of the 15th century, was considered its author. However, back in the last century it was established that this had never happened among the monks of the Benedictine order. Scientists have come to the conclusion that "Vasily Valentin" is a pseudonym of an unknown scientist who wrote his treatise no earlier than the middle of the 16th century. ... The name "antimony", given by him to natural sulphurous antimony, the German historian Lipman derives from the Greek ανεμον - "flower" (by the appearance of intergrowths of needle-like crystals of antimony luster, similar to flowers of the Compositae family).

The name "antimonium" both here and abroad for a long time referred only to this mineral. And at that time, metallic antimony was called the king of antimony - regulus antimoni. In 1789, Lavoisier included antimony in the list of simple substances and gave it the name antimonie, which remains the French name for element No. 51 to this day. The English and German names are close to it - antimony, Antimon.

There is, however, another version. She has fewer eminent supporters, but among them is the creator of Schweik - Yaroslav Hasek.

Between prayers and household chores, Father Leonardus, abbot of the Stahlhausen monastery in Bavaria, was looking for a philosopher's stone. In one of his experiments, he mixed in a crucible the ashes of a burned heretic with the ashes of his cat and double the amount of earth taken from the place of burning. The monk began to heat this "hellish mixture".

After evaporation, a heavy dark substance with a metallic sheen was obtained. It was unexpected and interesting; Nevertheless, Father Leonardus was annoyed: in the book that belonged to the burnt heretic, it was said that the stone of philosophers should be weightless and transparent... And Father Leonardus threw the resulting substance away from sin away - into the monastery courtyard.

After some time, he was surprised to notice that the pigs willingly lick the “stone” he threw out and at the same time quickly grow fat. And then Father Leonardus had a brilliant idea: he decided that he had discovered a nutrient that is also suitable for humans. He prepared a new portion of the "stone of life", crushed it and added this powder to the porridge, which his skinny brothers in Christ ate.

The next day, all forty monks of the Stahlhausen monastery died in terrible agony. Repenting of his deed, the abbot cursed his experiments, and renamed the “stone of life” into antimonium, that is, a remedy against monks.

It is difficult to vouch for the authenticity of the details of this story, but it is this version that is presented in the story of J. Hasek "The Stone of Life".

The etymology of the word "antimony" is discussed above in some detail. It remains only to add that the Russian name for this element - "antimony" - comes from the Turkish "surme", which translates as "rubbing" or "blackening of the eyebrows". Up until the 19th century. in Russia, there was an expression “to sullen eyebrows”, although they were “antimony” by no means always with antimony compounds. Only one of them - a black modification of trisulfuric antimony - was used as an eyebrow dye. It was first designated by a word, which later became the Russian name for the element.

Antimony has been known since ancient times. In the countries of the East, it was used approximately 3000 BC. e. for making vessels. In ancient Egypt already in the 19th century. BC e. antimony glitter powder (natural Sb 2 S 3) called mesten or stem used for blackening the eyebrows. In ancient Greece it was known as stimi And stibi, hence Latin stibium. About 12-14 centuries. n. e. the name appeared antimonium. In 1789 A. Lavoisier included antimony in the list of chemical elements under the name antimoine(Modern English antimony, Spanish and Italian antimonio, German Antimon). Russian "antimony" comes from Turkish surme; he designated the powder of lead shine PbS, which also served to blacken the eyebrows (according to other sources, “antimony” - from the Persian “surmium” - metal). A detailed description of the properties and methods for obtaining antimony and its compounds was first given by the alchemist Vasily Valentin (Germany) in 1604.

Finding antimony in nature

The average content of antimony in the earth's crust is 500 mg/t. Its content in igneous rocks is generally lower than in sedimentary ones. Of the sedimentary rocks, the highest concentrations of antimony are observed in clay shales (1.2 g/t), bauxites and phosphorites (2 g/t) and the lowest in limestones and sandstones (0.3 g/t). Elevated amounts of antimony are found in coal ash. Antimony, on the one hand, in natural compounds has the properties of a metal and is a typical chalcophile element, forming antimonite. On the other hand, it has the properties of a metalloid, manifested in the formation of various sulfosalts - bournonite, boulangerite, tetrahedrite, jamsonite, pyrargyrite, etc. Antimony can form intermetallic compounds with such metals as copper, arsenic and palladium. The ionic radius of antimony Sb 3+ is closest to the ionic radii of arsenic and bismuth, due to which there is an isomorphic substitution of antimony and arsenic in fahlore and geocronite Pb 5 (Sb, As) 2 S 8 and antimony and bismuth in cobellite Pb 6 FeBi 4 Sb 2 S 16; The volatility of antimony in a number of its compounds is relatively low. Antimony halides SbCl 3 have the highest volatility. Under supergene conditions (in near-surface layers and on the surface), antimonite undergoes oxidation approximately according to the following scheme: Sb 2 S 3 + 6O 2 = Sb 2 (SO 4) 3 . The resulting antimony oxide sulfate is very unstable and quickly hydrolyzes, turning into antimony ochers - sideboard Sb 2 O 4, stibioconite Sb 2 O 4 nH 2 O, valentinite Sb 2 O 3, etc. Solubility in water is rather low 1.3 mg / l, but it increases significantly in solutions of alkalis and sulfurous metals with the formation of a thioacid of the Na 3 SbS 3 type. Antimonite Sb 2 S 3 (71.7% Sb) has the main industrial importance. The sulfosalts tetrahedrite Cu 12 Sb 4 S 13 , bournonite PbCuSbS 3 , boulangerite Pb 5 Sb 4 S 11 and jamsonite Pb 4 FeSb 6 S 14 are of little importance.

Physical properties of antimony

In the free state, it forms silvery-white crystals with a metallic sheen, density 6.68 g/cm³. Resembling a metal in appearance, crystalline antimony is more brittle and less thermally and electrically conductive. Antimony is known in crystalline and three amorphous forms (explosive, black and yellow). Explosive Antimony (density 5.64-5.97 g / cm 3) explodes on any contact; formed during the electrolysis of a solution of SbCl 3 ; black (density 5.3 g / cm 3) - with rapid cooling of antimony vapor; yellow - when oxygen is passed into liquefied SbH 3 . Yellow and black antimony are unstable, at low temperatures they transform into ordinary antimony. The most stable crystalline antimony crystallizes in the trigonal system, a = 4.5064 Å; density 6.61-6.73 g / cm 3 (liquid - 6.55 g / cm 3); t pl 630.5 °C; kip t 1635-1645 °С: specific heat capacity at 20-100 °С 0.210 kJ/(kg K); thermal conductivity at 20 ° C 17.6 W / (m K) . Temperature coefficient of linear expansion for polycrystalline Antimony 11.5·10 -6 at 0-100 °C; for a single crystal a 1 = 8.1 10 -6, a 2 = 19.5 10 -6 at 0-400 ° C, electrical resistivity (20 ° C) (43.045 10 -6 cm cm). Antimony is diamagnetic, the specific magnetic susceptibility is -0.66·10 -6 . Unlike most metals, antimony is brittle, easily splits along cleavage planes, wears into powder and cannot be forged (sometimes it is referred to as semimetals). Mechanical properties depend on the purity of the metal. Brinell hardness for cast metal 325-340 MN / m 2 (32.5-34.0 kgf / mm 2); modulus of elasticity 285-300; ultimate strength 86.0 MN / m 2 (8.6 kgf / mm 2).

Antimony - metal or not metal?

Seven metals were known to medieval metallurgists and chemists: gold, silver, copper, tin, lead, iron and mercury. Zinc, bismuth and arsenic, discovered at that time, together with antimony, were allocated to a special group of "semimetals": they were worse forged, and ductility was considered the main feature of the metal. In addition, according to alchemical ideas, each metal was associated with some celestial body. And seven such bodies were known: the Sun (gold was associated with it), the Moon (silver), Mercury (mercury), Venus (copper), Mars (iron), Jupiter (tin) and Saturn (lead).

There was not enough celestial body for antimony, and on this basis, the alchemists did not want to recognize it as an independent metal. But, oddly enough, they were partially right, which is not difficult to confirm by analyzing the physical and chemical properties of antimony.

Chemical properties of antimony

The configuration of the outer electrons of the Sb atom is 5s 2 5p 3 . In compounds, it exhibits oxidation states mainly +5, +3 and -3. In chemical terms, it is inactive. It does not oxidize in air up to the melting point. It does not react with nitrogen and hydrogen. Carbon slightly dissolves in molten antimony. The metal actively interacts with chlorine and other halogens, forming antimony halides. It interacts with oxygen at temperatures above 630 ° C with the formation of Sb 2 O 3. When fused with sulfur, antimony sulfides are obtained, it also interacts with phosphorus and arsenic. Antimony is resistant to water and dilute acids. Concentrated hydrochloric and sulfuric acids slowly dissolve Antimony with the formation of chloride SbCl 3 and sulfate Sb 2 (SO 4) 3 ; concentrated nitric acid oxidizes antimony to a higher oxide, which is formed in the form of a hydrated compound xSb 2 O 5 yH 2 O. Slightly soluble salts of antimony acid - antimonates (MeSbO 3 3H 2 O, where Me - Na, K) and salts not isolated metaantimony acid - metaantimonites (MeSbO 2 ·3H 2 O), which have reducing properties. Antimony combines with metals to form antimonides.

A detailed analysis of the chemical properties of antimony also did not make it possible to finally remove it from the "neither this nor that" section. The outer, electronic layer of the antimony atom consists of five valence electrons s 2 p 3 . Three of them ( p-electrons) - unpaired and two ( s-electrons) are paired. The former more easily break away from the atom and determine the valency 3+ characteristic of antimony. With the manifestation of this valency, a pair of unshared valence electrons s 2 is in stock. When this reserve is used up, antimony becomes pentavalent. In short, it exhibits the same valencies as its counterpart in the group, the non-metal phosphorus.

Let us trace how antimony behaves in chemical reactions with other elements, for example, with oxygen, and what is the nature of its compounds.

When heated in air, antimony easily turns into oxide Sb 2 O 3 - a white solid, almost insoluble in water. In the literature, this substance is often called antimony anhydride, but this is incorrect. After all, anhydride is an acid-forming oxide, and in Sb (OH) 3, Sb 2 O 3 hydrate, basic properties clearly predominate over acid ones. The properties of the lower oxide of antimony indicate that antimony is a metal. But the highest oxide of antimony Sb 2 O 5 is really an anhydride with pronounced acidic properties. So antimony is still a non-metal?

There is also a third oxide - Sb 2 O 4. In it, one antimony atom is three-, and the other is pentavalent, and this oxide is the most stable. In its interaction with other elements - the same duality, and the question of antimony metal or non-metal remains open. Why, then, in all reference books does it appear among metals? Mainly for the sake of classification: you have to put it somewhere, but outwardly it looks more like metal ...

In medieval books, antimony was denoted by the figure of a wolf with an open mouth. Probably, such a “predatory” symbol of this metal is explained by the fact that antimony dissolves (“devours”) almost all other metals.

Technology for obtaining antimony

The metal is obtained by pyrometallurgical and hydrometallurgical processing of concentrates or ore containing 20-60% Sb. Pyrometallurgical methods include precipitation and reduction melting. Raw materials for precipitation smelting are sulfide concentrates; the process is based on the displacement of antimony from its sulfide by iron: Sb 2 S 3 + 3Fe => 2Sb + 3FeS. Iron is introduced into the charge in the form of scrap. Melting is carried out in reverberatory or short rotating drum furnaces at 1300-1400 °C. The extraction of antimony into crude metal is more than 90%. The reduction smelting of antimony is based on the reduction of its oxides to metal with charcoal or coal dust and the slagging of waste rock. Reduction melting is preceded by oxidizing firing at 550 °C with excess air. The cinder contains non-volatile antimony oxide. Electric furnaces can be used for both precipitation and reduction melts. The hydrometallurgical method of obtaining Antimony consists of two stages: treatment of raw materials with an alkaline sulfide solution with the transfer of Antimony into a solution in the form of antimony acid salts and sulfosalts and the isolation of Antimony by electrolysis. Rough Antimony, depending on the composition of the raw material and the method of its production, contains from 1.5 to 15% of impurities: Fe, As, S and others. To obtain pure antimony, pyrometallurgical or electrolytic refining is used. During pyrometallurgical refining, impurities of iron and copper are removed in the form of sulfur compounds by introducing antimonite (krudum) - Sb 2 S 3 into the antimony melt, after which arsenic (in the form of sodium arsenate) and sulfur are removed by blowing air under soda slag. During electrolytic refining with a soluble anode, crude antimony is purified from iron, copper and other metals remaining in the electrolyte (Cu, Ag, Au remain in the sludge). The electrolyte is a solution consisting of SbF 3 , H 2 SO 4 and HF. The content of impurities in refined Antimony does not exceed 0.5-0.8%. To obtain high purity Antimony, zone melting in an inert gas atmosphere is used or Antimony is obtained from previously purified compounds - oxide (III) or trichloride.

Application of antimony

Due to its brittleness, metallic antimony is rarely used. However, since antimony increases the hardness of other metals (tin, lead) and does not oxidize under normal conditions, metallurgists often introduce it into the composition of various alloys. The number of alloys in which the element is included is close to 200.

Antimony is mainly used in the form of alloys based on lead and tin for battery plates, cable sheaths, bearings (babbit), alloys used in printing (hart), etc. Such alloys have increased hardness, wear resistance, and corrosion resistance. In fluorescent lamps, calcium halophosphate activates Sb. Antimony is included in the composition of semiconductor materials as an alloying addition to germanium and silicon, as well as in the composition of antimonides (for example, InSb). The radioactive isotope 122 Sb is used in sources of γ-radiation and neutrons.

It is used in the semiconductor industry in the production of diodes, infrared detectors, Hall effect devices. It is a component of lead alloys, increasing their hardness and mechanical strength. The scope includes:

• batteries
• antifriction alloys
• printing alloys
• small arms and tracer bullets
• cable sheaths
• matches
• medicines, antiprotozoal drugs
• soldering - some lead-free solders contain 5% Sb
• use in linotype printing presses

Together with tin and copper, antimony forms a metal alloy - babbitt, which has antifriction properties and is used in plain bearings. Sb is also added to metals intended for thin castings.

Antimony compounds in the form of oxides, sulfides, sodium antimonate and antimony trichloride are used in the production of refractory compounds, ceramic enamels, glass, paints and ceramic products. Antimony trioxide is the most important of the antimony compounds and is mainly used in flame retardant compositions. Antimony sulfide is one of the ingredients in match heads.

The natural sulfide of antimony, stibnite, was used in biblical times in medicine and cosmetics. Stibnite is still used in some developing countries as a medicine.

Antimony compounds such as meglumine antimoniate (glucantim) and sodium stibogluconate (pentostam) are used in the treatment of leishmaniasis.

The effect of antimony on the human body

The content of antimony (per 100 g of dry matter) is 0.006 mg in plants, 0.02 mg in marine animals, and 0.0006 mg in terrestrial animals. Antimony enters the body of animals and humans through the respiratory organs or the gastrointestinal tract. It is excreted mainly with faeces, in small quantities - with urine. Antimony is selectively concentrated in the thyroid gland, liver, and spleen. Antimony accumulates predominantly in erythrocytes in the +3 oxidation state, in blood plasma - in the oxidation state. +5. The maximum allowable concentration of Antimony is 10 -5 - 10 -7 g per 100 g of dry tissue. At a higher concentration, this element inactivates a number of enzymes of lipid, carbohydrate and protein metabolism (possibly as a result of blocking sulfhydryl groups).

Antimony exhibits an irritating and cumulative effect. Accumulates in the thyroid gland, inhibits its function and causes endemic goiter. However, getting into the digestive tract, antimony compounds do not cause poisoning, since Sb (III) salts are hydrolyzed there with the formation of poorly soluble products. At the same time, antimony (III) compounds are more toxic than antimony (V). Dust and vapors of Sb cause nosebleeds, antimony "casting fever", pneumosclerosis, affect the skin, and disrupt sexual functions. The taste perception threshold in water is 0.5 mg/l. The lethal dose for an adult is 100 mg, for children - 49 mg. For antimony aerosols MPC in the air of the working area is 0.5 mg/m³, in the atmospheric air 0.01 mg/m³. MPC in soil 4.5 mg/kg. In drinking water, antimony belongs to the 2nd hazard class, has a MPC of 0.005 mg/l, established according to the sanitary-toxicological LPV. In natural waters, the content standard is 0.05 mg/l. In industrial waste water discharged to treatment facilities with biofilters, the content of antimony should not exceed 0.2 mg/l.

Description and properties of antimony

For the first time mankind began to use antimony long before our era. After all, until now, archaeologists find fragments or products from metallic antimony in the places of ancient Babylon, which corresponds to the beginning of the 3rd century BC. As an independent metal, antimony is rarely used in production, but mainly in compounds with other elements. The most popular application that has come down to our times is the use of the “antimony sheen” mineral in cosmetology as an eyeliner or paint for eyelashes and eyebrows.

In the periodic system of D. I. Mendeleev antimony is a chemical element, which belongs to the V group, its symbol is Sb. Atomic number 51, atomic mass 121.75, density 6620 kg/m3. Properties of antimony- color silvery-white with a bluish tint. By its structure, the metal is coarse-grained and very brittle, it can be easily ground by hand to a state of powder in a porcelain mortar and does not lend itself. The melting point of the metal is 630.5 ⁰С, the boiling point is 1634 °C.

In addition to the standard crystalline form, there are three more amorphous states of antimony in nature:

explosive antimony- is formed during the electrolysis of the SbCI3 compound in a hydrochloric acid medium and explodes upon impact or touch, thereby returning to its normal state.

yellow antimony- is obtained by the action of oxygen molecules O2 on the combination of hydrogen with antimony SbH 3.

Black antimony- is formed during the sharp cooling of yellow antimony vapor.

Under normal conditions antimony properties does not change its own, does not dissolve in water. Works well in the form antimony alloy with other metals, since its main advantage is an increase in the hardness of metals, for example, the connection lead - antimony(from 5–15%) is known as a garbtley. Even if you add 1% antimony to lead, its strength will already increase significantly.

Deposit and extraction of antimony

Antimony is an element, which is mined from ores. Antimony ores are called mineral formations containing antimony in such quantities that, when extracting pure metal, to obtain the maximum economic and industrial effect. According to the content of the main element - antimony, ores are classified:

- Very rich, Sb - within 50%.

- Rich, Sb - no more than 12%.

- Ordinary, Sb - from 2 to 6%.

- Poor, Sb - maximum 2%.

According to their composition, the above ores are divided into sulfide (up to 70% of the total mass is antimonite Sb 2 S 3), sulfide-oxide (up to 50% Sb in oxide compounds), and oxide (more than 50% of the total mass of ore in compounds antimony oxide). Very rich ores do not need to be enriched; antimony concentrate is immediately obtained from them and sent to the smelter. The extraction of antimony from ordinary and poor ores is not economically feasible. Such ores have to be enriched to a concentrate with an antimony content of up to 50%. The next step is the processing of the concentrate by pyrometallurgical and hydrometallurgical methods.

Pyrometallurgical methods include precipitation and reduction smelting processes. In the precipitation smelting process, the main raw material is sulfide ores. The principle of melting is as follows: at a temperature of 1300–1400 ° C, pure antimony sulfide is extracted with the help of iron. antimony, formula of this process –Sb2S3+3Fe=>2Sb+3FeS. Recovery smelting consists in the restoration of antimony oxides to metal with charcoal or coke dust. The hydrometallurgical method for extracting antimony consists of two stages - processing the ore with its transfer to a state of solution and extracting the metal from the solution.

Application of antimony

In its pure form, antimony is considered one of the most brittle metals, but when combined with other metals, it increases their hardness and the oxidation process does not occur under normal conditions. These advantages are deservedly appreciated in the industrial field, and now antimony is added to many alloys, more than 200.

Alloys for bearing production. This group includes compounds such as tin - antimony, lead - antimony, antimony - copper, since these alloys melt easily and are very convenient to pour into molds for bearing shells. The antimony content usually ranges from 4 to 15%, but in no case should this rate be exceeded, because an excess of antimony will break the metal. Such alloys have found their application in tank building, auto and railway transport.

One of the most important features of antimony is its ability to expand upon solidification. Based on this characteristic, an alloy was created - lead (82%), antimony(15%), tin (3%), it is also called "typographical alloy", because it perfectly fills the forms for different types of fonts and makes clear prints. In this case, antimony added impact resistance and wear resistance to the metal.

Alloyed with antimony, it is used in mechanical engineering, it is used to make plates for batteries and is also used in the manufacture of pipes, chutes through which aggressive liquids will be transported. Alloy zinc - antimony(zinc antimonide) is considered an inorganic compound. Due to its semiconductor property, it is used in the manufacture of transistors, thermal imagers and infrared detectors.

In addition to industrial use, antimony has found its wide application in cosmetology and medicine. Used from ancient times to the present day antimony for eyes, as a remedy and paint for eyebrows and eyelashes. Many people know the healing properties of antimony and with conjunctivitis and other infections of the eyes, antimony is immediately used.

According to their appearance and method of application, there are different types antimony - powder, with the help of a wooden stick, it is easily applied to the area of ​​\u200b\u200bthe eyelid, but first it is necessary to soak in any oil; pencil - perfectly clearly draws arrows on the eyelid, this pencil is the same antimony powder, just pressed into shape.

If in ancient times antimony paint was environmentally friendly and brought a truly healing effect, then in our time you need to be extremely careful and carefully read the composition before buying. Everything is connected with the fact that now unscrupulous producers extract pure antimony from ore of poor quality, and impurities of heavy metals, such as arsenic, remain. It is difficult to imagine the harm done to the human body from the compound arsenic-antimony.

Antimony price

Due to the unstable situation in the world market, there is no single value for the metal antimony. Price it ranges from $6,300 to $8,300/ton, over the past two months there has been a negative trend in price growth, this is directly related to the main producer - China and its foreign economic relations.

But the political and economic vicissitudes had no effect on antimony for the eyes. Oriental culture and other accessories are in fashion now, including antimony. Buy it will not be difficult, as there is a huge selection in oriental shops, or you can place an order in an online store.