Antimony is a toxic
chemical elementA chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
with the symbol
Sb and an
atomic numberIn chemistry and physics, the atomic number is the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus. It is conventionally represented by the symbol Z. The atomic number uniquely identifies a chemical element...
of 51. A lustrous grey
metalloidMetalloid is a term used in chemistry when classifying the chemical elements. On the basis of their general physical and chemical properties, each element can usually be classified as a metal or a nonmetal. However, some elements with intermediate or mixed properties can be harder to characterize...
, it is found in nature mainly as the
sulfide mineralThe sulfide minerals are a class of minerals containing sulfide as the major anion. Some sulfide minerals are economically important as metal ores. The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, the sulfarsenides and the sulfosalts...
stibniteStibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb2S3. This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony...
(Sb
2S
3). Although the use of antimony is limited by its toxicity, its compounds have been of fundamental value in chemistry – a prominent example being the development of
superacidAccording to the classical definition superacid is an acid with an acidity greater than that of 100% pure sulfuric acid, which has a Hammett acidity function of −12. According to the modern definition, superacid is a medium, in which the chemical potential of the proton is higher than in pure...
s derived from
antimony pentafluorideAntimony pentafluoride is the inorganic compound with the formula SbF5. This colourless, viscous liquid is a valuable Lewis acid and a component of the superacid fluoroantimonic acid, the strongest known acid...
. Antimony compounds are prominent
fire retardantA fire retardant is a substance other than water that reduces flammability of fuels or delays their combustion. This typically refers to chemical retardants but may also include substances that work by physical action, such as cooling the fuels; examples of these include fire-fighting foams and...
s found in many commercial and domestic products. Certain
alloyAn alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
s are valuable for use in
solderSolder is a fusible metal alloy used to join together metal workpieces and having a melting point below that of the workpiece.Soft solder is what is most often thought of when solder or soldering are mentioned and it typically has a melting range of . It is commonly used in electronics and...
s and
ball bearingA ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit...
s. An emerging application is the use of antimony in
microelectronicsMicroelectronics is a subfield of electronics. As the name suggests, microelectronics relates to the study and manufacture of very small electronic components. Usually, but not always, this means micrometre-scale or smaller,. These devices are made from semiconductors...
.
History
Antimony's sulfide compound, antimony(III) sulfide, Sb
2S
3 was recognized in antiquity, at least as early as
3000 BCThe 4th millennium BC saw major changes in human culture. It marked the beginning of the Bronze Age and of writing.The city states of Sumer and the kingdom of Egypt were established and grew to prominence. Agriculture spread widely across Eurasia...
.
An artifact, said to be part of a vase, made of antimony dating to about 3000 BC was found at Tello,
ChaldeaChaldea or Chaldaea , from Greek , Chaldaia; Akkadian ; Hebrew כשדים, Kaśdim; Aramaic: ܟܐܠܕܘ, Kaldo) was a marshy land located in modern-day southern Iraq which came to briefly rule Babylon...
(part of present-day
IraqIraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....
), and a copper object plated with antimony dating between 2500 BC and 2200 BC has been found in
EgyptEgypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
. One contemporary (Austen, at a lecture by Herbert Gladstone, published in 1892) was reported to comment that "we only know of antimony at the present day as a highly brittle and crystalline metal, which could hardly be fashioned into a useful vase, and therefore this remarkable 'find' must represent the lost art of rendering antimony malleable." However, Moorey was unconvinced that the artefact was indeed a vase, mentioning that Selimkhanov, after his analysis of the Telloh object (published in 1975), "attempted to relate the metal to Transcaucasian natural antimony" (i.e. native metal) and that "the antimony objects from Transcaucasia are all small personal ornaments." This weakens the evidence for a lost art "of rendering antimony malleable."
The first European description of a procedure for isolating antimony is in the book
De la pirotechniaDe la Pirotechnia is considered to be the first printed book on metallurgy to have been published in Europe. It was written in Italian and published in Venice in 1540...
of 1540 by
Vannoccio Biringuccio- External links :*...
. This book predates the more famous 1556 book by
AgricolaGeorgius Agricola was a German scholar and scientist. Known as "the father of mineralogy", he was born at Glauchau in Saxony. His real name was Georg Pawer; Agricola is the Latinised version of his name, Pawer meaning "farmer"...
,
De re metallicaDe re metallica is a book cataloguing the state of the art of mining, refining, and smelting metals, published in 1556. The author was Georg Bauer, whose pen name was the Latinized Georgius Agricola...
, even though Agricola has been often incorrectly credited with the discovery of metallic antimony. A text describing the preparation of metallic antimony that was published in Germany in 1604 purported to date from the early fifteenth century, and if authentic it would predate Biringuccio. The book, written in Latin, was called "Currus Triumphalis Antimonii" (The Triumphal Chariot of Antimony), and its putative author was a certain
BenedictineBenedictine refers to the spirituality and consecrated life in accordance with the Rule of St Benedict, written by Benedict of Nursia in the sixth century for the cenobitic communities he founded in central Italy. The most notable of these is Monte Cassino, the first monastery founded by Benedict...
monk, writing under the name
Basilius ValentinusBasil Valentine is the Anglicised version of the name Basilius Valentinus, who was allegedly a 15th-century alchemist. There are claims that he was the Canon of the Benedictine Priory of Sankt Peter in Erfurt, Germany but according to John Maxson Stillman, who wrote on the history of chemistry,...
. An English translation of the "Currus Triumphalis" appeared in English in 1660, under the title The Triumphant Chariot of Antimony. The work remains of great interest, chiefly because it documents how followers of the renegade German physician, Philippus Theophrastus
ParacelsusParacelsus was a German-Swiss Renaissance physician, botanist, alchemist, astrologer, and general occultist....
von Hohenheim (of whom Thölde was one), came to associate the practice of alchemy with the preparation of chemical medicines.
Pure antimony was well known to Jābir ibn Hayyān, sometimes called "the Father of Chemistry", in the 8th century. Here there is still an open controversy:
Marcellin BerthelotMarcelin Pierre Eugène Berthelot was a French chemist and politician noted for the Thomsen-Berthelot principle of thermochemistry. He synthesized many organic compounds from inorganic substances and disproved the theory of vitalism. He is considered as one of the greatest chemists of all time.He...
, who translated a number of Jābir's books, stated that antimony is never mentioned in them, but other authors claim that Berthelot translated only some of the less important books, while the more interesting ones (some of which might describe antimony) are not yet translated, and their content is completely unknown.
The first natural occurrence of pure antimony ('native antimony') in the Earth's crust was described by the Swedish scientist and local mine district engineer Anton von Swab in 1783. The
type-sampleType locality , also called type area or type locale, is the where a particular rock type, stratigraphic unit, fossil or mineral species is first identified....
was collected from the Sala Silver Mine in the Bergslagen mining district of Sala,
VästmanlandVästmanland County is a county or län in central Sweden. It borders to the counties of Södermanland, Örebro, Gävleborg, Dalarna and Uppsala...
,
SwedenSweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
.
Etymology
The ancient words for antimony mostly have, as their chief meaning,
kohlKohl is an ancient eye cosmetic. It was made by grinding galena and other ingredients. It is widely used in South Asia, the Middle East, North Africa, the Horn of Africa, and parts of West Africa to darken the eyelids and as mascara for the eyelashes...
, the sulfide of antimony.
Pliny the ElderGaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...
, however, distinguishes between male and female forms of antimony; his male form is probably the sulfide, while the female form, which is superior, heavier, and less friable, is probably native metallic antimony.
The Egyptians called antimony
mśdmt; in
hieroglyphsHieroglyph or hieroglyphics may refer to:*Anatolian hieroglyphs*Chinese character*Cretan hieroglyphs*Cursive hieroglyphs*Dongba script*Egyptian hieroglyphs*Hieroglyphic Luwian*Mayan hieroglyphs...
, the vowels are uncertain, but there is an Arabic tradition that the word is ميسديميت
mesdemet. The Greek word,
στίμμι stimmi, is probably a loan word from Arabic or Egyptian
sdm O34:D46-G17-F21:D4, and is used by the Attic tragic
poetA poet is a person who writes poetry. A poet's work can be literal, meaning that his work is derived from a specific event, or metaphorical, meaning that his work can take on many meanings and forms. Poets have existed since antiquity, in nearly all languages, and have produced works that vary...
s of the 5th century BC; later Greeks also used
στἰβι stibi, as did
CelsusAulus Cornelius Celsus was a Roman encyclopedist, known for his extant medical work, De Medicina, which is believed to be the only surviving section of a much larger encyclopedia. The De Medicina is a primary source on diet, pharmacy, surgery and related fields, and it is one of the best sources...
and
PlinyGaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...
, writing in Latin, in the first century AD. Pliny also gives the names
stimi [
sic],
larbaris,
alabasterAlabaster is a name applied to varieties of two distinct minerals, when used as a material: gypsum and calcite . The former is the alabaster of the present day; generally, the latter is the alabaster of the ancients...
, and the "very common"
platyophthalmos, "wide-eye" (from the effect of the cosmetic). Later Latin authors adapted the word to Latin as
stibium. The Arabic word for the substance, as opposed to the cosmetic, can appear as تحميض، ثمود، وثمود، وثمود
ithmid, athmoud, othmod, or
uthmod. Littré suggests the first form, which is the earliest, derives from
stimmida, (one) accusative for
stimmi.
The use of Sb as the standard chemical symbol for antimony is due to the 18th century chemical pioneer,
Jöns Jakob BerzeliusJöns Jacob Berzelius was a Swedish chemist. He worked out the modern technique of chemical formula notation, and is together with John Dalton, Antoine Lavoisier, and Robert Boyle considered a father of modern chemistry...
, who used this abbreviation of the name
stibium. The medieval Latin form, from which the modern languages and late Byzantine Greek, take their names, is
antimonium. The origin of this is uncertain; all suggestions have some difficulty either of form or interpretation. The popular etymology, from
ἀντίμοναχός anti-monachos or French
antimoine, still has adherents; this would mean "monk-killer", and is explained by many early
alchemistAn alchemist is a person who practices alchemy. Alchemist may also refer to:-People and groups:*The Alchemist , a hip hop music producer and rapper*Alchemist , an Australian progressive metal band...
s being monks, and antimony being poisonous.
[The use of a symbol resembling an upside down "female" symbol for antimony could also hint at a satirical pun in this origin] So does the hypothetical Greek word
ἀντίμόνος antimonos, "against one", explained as "not found as metal", or "not found unalloyed".
Lippmann conjectured a Greek word,
ανθήμόνιον anthemonion, which would mean "floret", and he cites several examples of related Greek words (but not that one) which describe chemical or biological
efflorescenceIn chemistry, efflorescence is the loss of water of crystallization from a hydrated or solvated salt to the atmosphere on exposure to air.-Examples:...
.
The early uses of
antimonium include the translations, in 1050–1100, by
Constantine the AfricanConstantine the African was a Tunisian doctor of the eleventh century. The first part of his life was spent in Tunisia and the rest in Italy. In Salerno, Italy, he became a professor of medicine and his work attracted widespread attention...
of Arabic medical treatises. Several authorities believe that
antimonium is a scribal corruption of some Arabic form; Meyerhof derives it from
ithmid; other possibilities include
Athimar, the Arabic name of the
metal, and a hypothetical
as-stimmi, derived from or parallel to the Greek.
Properties
Antimony is in the
nitrogen groupThe nitrogen group is a periodic table group consisting of nitrogen , phosphorus , arsenic , antimony , bismuth and ununpentium ....
(group 15) and has an
electronegativityElectronegativity, symbol χ , is a chemical property that describes the tendency of an atom or a functional group to attract electrons towards itself. An atom's electronegativity is affected by both its atomic number and the distance that its valence electrons reside from the charged nucleus...
of 2.05. As expected by periodic trends, it is more electronegative than
tinTin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
or
bismuthBismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...
, and less electronegative than
tellurium or
arsenicArsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
.
Antimony is stable in air at room temperature but reacts with
oxygenOxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
if heated to form
antimony trioxideAntimony trioxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite...
, Sb
2O
3.
Antimony is a silvery, lustrous gray metal that has a Mohs scale hardness of 3. Therefore, antimony by itself is not used to make hard objects: coins made of antimony were issued in China's
Guizhou' is a province of the People's Republic of China located in the southwestern part of the country. Its provincial capital city is Guiyang.- History :...
province in 1931, but because of their rapid wear their minting was discontinued. Antimony is resistant to attack by acids.
Four
allotropesAllotropy or allotropism is the property of some chemical elements to exist in two or more different forms, known as allotropes of these elements...
of antimony are known: a stable metallic form, and three metastable forms: explosive, black and yellow. Metallic antimony is a
brittleA material is brittle if, when subjected to stress, it breaks without significant deformation . Brittle materials absorb relatively little energy prior to fracture, even those of high strength. Breaking is often accompanied by a snapping sound. Brittle materials include most ceramics and glasses ...
, silver-white shiny metal. When molten antimony is slowly cooled, metallic antimony crystallizes in an hexagonal cell, isomorphic with that of the grey allotrope of
arsenicArsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
. A rare explosive form of antimony can be formed from the electrolysis of antimony(III) trichloride. When scratched with a sharp implement, an
exothermicIn thermodynamics, the term exothermic describes a process or reaction that releases energy from the system, usually in the form of heat, but also in the form of light , electricity , or sound...
reaction occurs and white fumes given off as metallic antimony is formed; alternatively, when rubbed with a pestle in a mortar, a strong detonation occurs. Black antimony is formed upon rapid cooling of gaseous metallic antimony. It has the same crystal structure as red phosphorus and black arsenic, it oxidizes in air and may ignite spontaneously. At 100 °C, it gradually transforms into the stable form. The yellow allotrope of antimony is the most unstable. It has only been generated by oxidation of
stibineStibine is the chemical compound with the formula SbH3. This colourless gas is the principal covalent hydride of antimony and a heavy analogue of ammonia. The molecule is pyramidal with H–Sb–H angles of 91.7° and Sb–H distances of 1.707 Å...
(SbH
3) at −90 °C. Above this temperature and in ambient light, this meta stable allotrope transforms into the more stable black allotrope.
Metallic antimony adopts a double-layered structure (
space groupIn mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...
Rm No. 166) consisting of many interlocked ruffled six-membered rings. Nearest and next-nearest neighbors form a distorted octahedral complex, with the three atoms in the same double-layer being slightly closer than the three atoms in the next. This relatively close packing leads to a high density of 6.697 g/cm
3 whereas the low hardness and brittleness of antimony originate from the weak bonding among the layers.
Isotopes
Antimony exists as two stable isotopes,
121Sb with a natural abundance of 57.36% and
123Sb with a natural abundance of 42.64%. It also has 35 radioisotopes, of which the longest-lived is
125Sb with a
half-lifeHalf-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 2.75 years. In addition, 29
metastableA nuclear isomer is a metastable state of an atomic nucleus caused by the excitation of one or more of its nucleons . "Metastable" refers to the fact that these excited states have half-lives more than 100 to 1000 times the half-lives of the other possible excited nuclear states...
states have been characterised.
Occurrence
The abundance of antimony in the
EarthEarth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's crust is estimated at 0.2 to 0.5 parts per million, comparable to
thalliumThallium is a chemical element with the symbol Tl and atomic number 81. This soft gray poor metal resembles tin but discolors when exposed to air. The two chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861 by the newly developed method of flame spectroscopy...
at 0.5 parts per million and silver at 0.07 ppm. Even though this element is not abundant, it is found in over 100
mineralA mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
species. Antimony is sometimes found native, but more frequently it is found in the sulfide
stibniteStibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb2S3. This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony...
(Sb
2S
3) which is the predominant ore
mineralA mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
. Commercial forms of antimony are generally
ingotAn ingot is a material, usually metal, that is cast into a shape suitable for further processing. Non-metallic and semiconductor materials prepared in bulk form may also be referred to as ingots, particularly when cast by mold based methods.-Uses:...
s, broken pieces,
granulesA granular material is a conglomeration of discrete solid, macroscopic particles characterized by a loss of energy whenever the particles interact . The constituents that compose granular material must be large enough such that they are not subject to thermal motion fluctuations...
, and cast cake. Other forms are
powderA powder is a dry,thick bulk solid composed of a large number of very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms powder and granular are sometimes used to distinguish separate classes of material...
, shot, and
single crystalA single crystal or monocrystalline solid is a material in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample, with no grain boundaries...
s.
In 2005, the People's Republic of China was the top producer of antimony with about 84% world share followed at a distance by South Africa, Bolivia and Tajikistan, reports the
British Geological SurveyThe British Geological Survey is a partly publicly funded body which aims to advance geoscientific knowledge of the United Kingdom landmass and its continental shelf by means of systematic surveying, monitoring and research. The BGS headquarters are in Keyworth, Nottinghamshire, but other centres...
. The mine with the largest deposits in China is
Xikuangshan MineXikuangshan mine in Lengshuijiang, Hunan, China, contains the world's largest deposit of antimony. It is unique in that there is a large deposit of stibnite in a layer of Devonian limestone. There are three mineral beds which are between 2.5 and 8 m thick which are folded in an anticline that...
in
Hunan' is a province of South-Central China, located to the south of the middle reaches of the Yangtze River and south of Lake Dongting...
province with a estimated deposit of 2.1 million metric tons.
In October 2011 a deposit of antimony was found in a shallow seabed about 50 km off Amami-Oshima Island in Kagoshima Prefecture. The discovery was the first time that antimony had been found at such shallow depths(480 meters), with this type of mineral deposit only ever having been found in depths in excess of 1000 meters.
Production
The extraction of antimony from ores depends on the quality of the ore, which is usually a sulfide. The sulfide is converted to an oxide and advantage is often taken of the volatility of antimony(III) oxide, which is recovered from roasting. This material is often used directly for the main applications, impurities being arsenic and sulfide. Antimony can be isolated from its ore by a reduction with scrap iron:
- + 3 Fe → 2 Sb + 3 FeS
Isolating antimony from its oxide is performed by a carbothermal reduction:
- 2 + 3 C → 4 Sb + 3
Compounds
Antimony compounds are often classified into those of Sb(III) and Sb(V). Relative to its neighboring element As, the 5+ oxidaton state is more stable.
Oxides and hydroxides
Antimony trioxideAntimony trioxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite...
is formed when antimony is burnt in air.
In the gas phase, this compound exists as , but it polymerises upon condensing.
Antimony pentoxideAntimony pentoxide is a chemical compound of antimony and oxygen. It always occurs in hydrated form, Sb2O5·nH2O. It contains antimony in the +5 oxidation state.-Structure:...
, can only be formed by oxidation by concentrated
nitric acidNitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...
. Antimony also forms a mixed-valence oxide,
antimony tetroxideAntimony tetroxide is an inorganic compound with the formula Sb2O4. This material, which exists as the mineral cervantite, is white but reversibly yellows upon heating...
, which features both Sb(III) and Sb(V). Unlike
phosphorusPhosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
and
arsenicArsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
, these various oxides are amphoteric and do not form well-defined
oxoacidAn oxoacid is an acid that contains oxygen. To be more specific, it is an acid that:#contains oxygen#contains at least one other element#has at least one hydrogen atom bound to oxygen#forms an ion by the loss of one or more protons....
s and react with acids to form antimony salts.
Antimonous acid is unknown but the conjugate base sodium antimonite forms upon fusing
sodium oxideSodium oxide is a chemical compound with the formula Na2O. It is used in ceramics and glasses, though not in a raw form. Treatment with water affords sodium hydroxide....
and . Transition metal antimonites are also known. Antimonic acid exists only as the hydrate , forming salts containing the antimonate anion . Dehydrating metal salts containing this anion yields mixed oxides.
Many antimony ores are sulfides, including
stibniteStibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb2S3. This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony...
,
pyrargyritePyrargyrite is a sulfosalt mineral consisting of silver sulfantimonide, Ag3SbS3. Known also as dark red silver ore or ruby silver, it is an important source of the metal....
,
zinkeniteZinkenite is a steel-gray metallic sulfosalt mineral composed of lead antimony sulfide Pb9Sb22S42. Zinkenite occurs as acicular needle-like crystals....
,
jamesoniteJamesonite is a sulfosalt mineral, a lead, iron, antimony sulfide with formula Pb4FeSb6S14. With the addition of manganese it forms a series with benavidesite. It is a dark grey metallic mineral which forms acicular prismatic monoclinic crystals. It is soft with a Mohs hardness of 2.5 and has a...
, and
boulangeriteBoulangerite is a sulfosalt mineral, lead antimony sulfide, formula Pb5Sb4S11. It was named in 1837 in honor of French mining engineer Charles Boulanger. It forms metallic grey monoclinic crystals. Sometimes the crystals form a fine feathery mass which has been called plumosite....
.
Antimony pentasulfideAntimony pentasulfide is an inorganic compound of antimony and sulfur, also known as antimony red. It is a nonstoichiometric compound with a variable composition. Commercial samples are usually are contaminated with sulfur, which may be removed by washing with carbon disulfide in a Soxhlet...
is
non-stoichiometricNon-stoichiometric compounds are chemical compounds with an elemental composition that cannot be represented by a ratio of well-defined natural numbers, and therefore violate the law of definite proportions. Often, they are solids that contain crystallographic point defects, such as interstitial...
and features antimony in the +3
oxidation stateIn chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. The formal oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic. Oxidation states are typically represented by...
and S-S bonds. Several thioantimonides are known such as and .
Halides
Antimony forms two series of
halideA halide is a binary compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative than the halogen, to make a fluoride, chloride, bromide, iodide, or astatide compound. Many salts are halides...
s, and . The trihalides
Antimony trifluoride is the inorganic compound with the formula SbF3. Sometimes called Swart's reagent, is one of two principal fluorides of antimony, the other being SbF5. It appears as a white solid...
,
Antimony trichloride is the chemical compound with the formula SbCl3. The soft colorless solid with a pungent odor was known to the alchemists as butter of antimony.-Preparation:...
,
Antimony tribromide is a chemical compound containing antimony in its +3 oxidation state. It may be made by the reaction of antimony with elemental bromine or the reaction of antimony trioxide with hydrobromic acid. It can be added to polymers such as polyethylene as a fire retardant...
, and
Antimony triiodide is the chemical compound with the formula SbI3. This ruby-red solid is the only characterized "binary" iodide of antimony, i.e. the sole compound isolated with the formula SbxIy. It contains antimony in its +3 oxidation state. Like many iodides of the heavier main group...
are all molecular compounds having trigonal pyramidal molecular geometry. The trifluoride is prepared by the reaction of with
HFHydrofluoric acid is a solution of hydrogen fluoride in water. It is a valued source of fluorine and is the precursor to numerous pharmaceuticals such as fluoxetine and diverse materials such as PTFE ....
:
- + 6 HF → 2 + 3
It is
Lewis acid]The term Lewis acid refers to a definition of acid published by Gilbert N. Lewis in 1923, specifically: An acid substance is one which can employ a lone pair from another molecule in completing the stable group of one of its own atoms. Thus, H+ is a Lewis acid, since it can accept a lone pair,...
ic and readily accepts fluoride ions to form the complex anions and . Molten is a weak
electrical conductorIn physics and electrical engineering, a conductor is a material which contains movable electric charges. In metallic conductors such as copper or aluminum, the movable charged particles are electrons...
. The trichloride is prepared by dissolving
Stibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb2S3. This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony...
in
hydrochloric acidHydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
:
- + 6 HCl → 2 + 3
The pentahalides and have trigonal bipyramidal molecular geometry in the gas phase, but in the liquid phase, is
polymerA polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
ic, whereas is monomeric.
Antimony pentafluoride is the inorganic compound with the formula SbF5. This colourless, viscous liquid is a valuable Lewis acid and a component of the superacid fluoroantimonic acid, the strongest known acid...
is a powerful Lewis acid used to make the superacid
fluoroantimonic acidFluoroantimonic acid is a mixture of hydrogen fluoride and antimony pentafluoride in various ratios. The 1:1 combination forms the strongest known superacid, which has been demonstrated to protonate even hydrocarbons to afford carbocations and H2....
("HSbF
6").
Oxyhalides are more common for antimony than arsenic and phosphorus. Antimony trioxide dissolves in concentrated acid to form antimony oxo- (antimonyl) compounds such as SbOCl and .
Antimonides, hydrides, and organoantimony compounds
Compounds in this class generally are described as derivatives of Sb
3-. Antimony forms
antimonides with metals, such as indium antimonide (InSb), and silver antimonide . The alkali metal and zinc antimonides, e.g. Na
3Sb and Zn
3Sb
2, are more reactive. Treating these antimonides with acid produces the unstable gas
stibineStibine is the chemical compound with the formula SbH3. This colourless gas is the principal covalent hydride of antimony and a heavy analogue of ammonia. The molecule is pyramidal with H–Sb–H angles of 91.7° and Sb–H distances of 1.707 Å...
, :
- + 3 →
Stibine can also be produced by treating salts with hydride reagents such as
sodium borohydrideSodium borohydride, also known as sodium tetrahydridoborate, is an inorganic compound with the formula NaBH4. This white solid, usually encountered as a powder, is a versatile reducing agent that finds wide application in chemistry, both in the laboratory and on a technical scale. Large amounts are...
. Stibine decomposes spontaneously at room temperature. Because stibine is thermodynamically unstable (positive heat of formation), antimony does not react with hydrogen directly.
Organoantimony compoundOrganoantimony chemistry is the chemistry of compounds containing a carbon to antimony chemical bond. Relevant oxidation states are Sb and Sb...
s are typically prepared by alkylation of antimony halides with Grignard reagents. A large variety of compounds are known with both Sb(III) and Sb(V) centers including mixed chloro-organic derivatives, anions, and cations. Examples include Sb(C
6H
5)
3 (
triphenylstibineTriphenylstibine is the chemical compound with the formula Sb3. Abbreviated SbPh3, this colourless solid is often considered the prototypical organoantimony compound...
), Sb
2(C
6H
5)
4 (with an Sb-Sb bond), and cyclic [Sb(C
6H
5)]
n. Pentacoordinated organoantimony compounds are common, examples being Sb(C
6H
5)
5 and several related halides.
Flame retardants
The main use of antimony is in the form of
antimony trioxideAntimony trioxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite...
is used in the making of
flame-proofing compoundsFlame retardants are chemicals used in thermoplastics, thermosets, textiles and coatings that inhibit or resist the spread of fire. These can be separated into several different classes of chemicals:...
. Markets for these flame-retardant applications include children's clothing, toys, aircraft and automobile seat covers. It is also used in the
fiberglassFiberglass , is a fiber reinforced polymer made of a plastic matrix reinforced by fine fibers of glass. It is also known as GFK ....
compositesComposite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
industry as an additive to
polyester resinPolyester resins are unsaturated resins formed by the reaction of dibasic organic acids and polyhydric alcohols. Polyester resins are used in sheet moulding compound, bulk moulding compound and the toner of laser printers...
s for such items as light aircraft engine covers. The resin will burn while a flame is held to it but will extinguish itself as soon as the flame is removed. Fireproofing consumes about half of the annual production of antimony.
Alloys
Antimony forms a highly useful
alloyAn alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
with
leadLead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
, increasing its hardness and mechanical strength. The Sb–Pb alloy is used in lead–acid batteries. It is used in antifriction alloys, such as
Babbitt metalBabbitt, also called Babbitt metal or bearing metal, is any of several alloys used for the bearing surface in a plain bearing.The original Babbitt metal was invented in 1839 by Isaac Babbitt in Taunton, Massachusetts, USA. Other formulations were later developed...
. It is used as an alloy in
bulletA bullet is a projectile propelled by a firearm, sling, or air gun. Bullets do not normally contain explosives, but damage the intended target by impact and penetration...
s and
lead shotLead shot is a collective term for small balls of lead. These were the original projectiles for muskets and early rifles, but today lead shot is fired primarily from shotguns. It is also used for a variety of other purposes...
,
cableA cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry...
sheathing,
type metalIn printing, type metal refers to the metal alloys used in traditional typefounding and hot metal typesetting. Lead is the main constituent of these alloys...
(e.g. for
linotypeThe Linotype typesetting machine is a "line casting" machine used in printing. The name of the machine comes from the fact that it produces an entire line of metal type at once, hence a line-o'-type, a significant improvement over manual typesetting....
printing machines),
solderSolder is a fusible metal alloy used to join together metal workpieces and having a melting point below that of the workpiece.Soft solder is what is most often thought of when solder or soldering are mentioned and it typically has a melting range of . It is commonly used in electronics and...
– some "lead-free" solders contain 5% Sb, in
pewterPewter is a malleable metal alloy, traditionally 85–99% tin, with the remainder consisting of copper, antimony, bismuth and lead. Copper and antimony act as hardeners while lead is common in the lower grades of pewter, which have a bluish tint. It has a low melting point, around 170–230 °C ,...
, and in hardening alloys with low
tinTin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
content in the manufacturing of
organ pipeAn organ pipe is a sound-producing element of the pipe organ that resonates at a specific pitch when pressurized air is driven through it. Each pipe is tuned to a specific note of the musical scale...
s.
Other applications
The second main application is as a catalyst for the production of the polymer polyethyleneterephthalate. It is an additive in some
glassGlass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
es. In the latter application, antimony oxides serve as fining agents, aiding in the removal of microscopic bubbles. This application is mainly used for TV screens.
Microelectronics
In tiny amounts, antimony is increasingly being used in the
semiconductorA semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
industry as a
dopantA dopant, also called a doping agent, is a trace impurity element that is inserted into a substance in order to alter the electrical properties or the optical properties of the substance. In the case of crystalline substances, the atoms of the dopant very commonly take the place of elements that...
for ultra-high conductivity
n-typeN-type semiconductors are a type of extrinsic semiconductor where the dopant atoms are capable of providing extra conduction electrons to the host material . This creates an excess of negative electron charge carriers....
siliconSilicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
wafersA wafer is a thin slice of semiconductor material, such as a silicon crystal, used in the fabrication of integrated circuits and other microdevices...
in the production of
diodeIn electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...
s,
infraredInfrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
detectors, and
Hall-effectThe Hall effect is the production of a voltage difference across an electrical conductor, transverse to an electric current in the conductor and a magnetic field perpendicular to the current...
devices.
In the 1950s, tiny beads of a
leadLead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
-antimony alloy were used to dope the emitters and collectors of NPN alloy junction transistors with antimony.
Medical
Few biological or medical applications exist for antimony. Treatments principally containing antimony are known as
antimonialAntimonials, in pre-modern medicine, were remedies principally containing antimony, used chiefly for emetic purposes. They might also have qualified for cathartic, diaphoretic, or simply alterative uses...
s and are used as emetics.
Antimony compounds are used as
antiprotozoanAntiprotozoal agents is a class of pharmaceuticals used in treatment of protozoan infection.Protozoans have little in common with each other and so agents effective against one pathogen may not be effective against another...
drugs. Antimony potassium tartrate, or tartar emetic, was once used as an anti-
schistosomalSchistosomiasis is a parasitic disease caused by several species of trematodes , a parasitic worm of the genus Schistosoma. Snails often act as an intermediary agent for the infectious diseases until a new human host is found...
drug, subsequently replaced by
praziquantelPraziquantel is an anthelmintic effective against flatworms. Praziquantel is not licensed for use in humans in the UK; it is, however, available as a veterinary anthelmintic, and is available for use in humans on a named-patient basis....
.
Antimony and its compounds are used in several veterinary preparations like anthiomaline or lithium antimony thiomalate, which is used as a skin conditioner in
ruminantA ruminant is a mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first compartment of the stomach, principally through bacterial actions, then regurgitating the semi-digested mass, now known as cud, and chewing it again...
s.
Antimony has a nourishing or conditioning effect on keratinized tissues, at least in animals.
Antimony-based drugs, such as
meglumine antimoniateMeglumine antimoniate is a medicine used for treating leishmaniasis. It is manufactured by Aventis and sold as Glucantime in France, and Glucantim in Italy. It belongs to a group of compounds known as the pentavalent antimonials. It is administered by intramuscular injection....
, are also considered the drugs of choice for treatment of
leishmaniasisLeishmaniasis is a disease caused by protozoan parasites that belong to the genus Leishmania and is transmitted by the bite of certain species of sand fly...
in domestic animals. Unfortunately, as well as having low
therapeutic indicesThe therapeutic index is a comparison of the amount of a therapeutic agent that causes the therapeutic effect to the amount that causes death or toxicity ....
, the drugs are poor at penetrating the
bone marrowBone marrow is the flexible tissue found in the interior of bones. In humans, bone marrow in large bones produces new blood cells. On average, bone marrow constitutes 4% of the total body mass of humans; in adults weighing 65 kg , bone marrow accounts for approximately 2.6 kg...
, where some of the
Leishmania amastigoteAn amastigote is a cell that does not have a visible external flagella or cilia. The term is used mainly to describe a certain phase in the life-cycle of trypanosome protozoans. It is also called the leishmanial stage, since in Leishmania it is the form the parasite takes in the vertebrate host,...
s reside, and so cure of the disease – especially the visceral form – is very difficult.
Elemental antimony as an
antimony pillAn Antimony pill is a pill made from metallic antimony. It was a popular remedy in the nineteenth century, and it was used to purge and revitalise the bowels...
was once used as a medicine. It could be reused by others after ingestion.
Other uses
In the heads of some safety matches and in
nuclear reactorA nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...
s together with
berylliumBeryllium is the chemical element with the symbol Be and atomic number 4. It is a divalent element which occurs naturally only in combination with other elements in minerals. Notable gemstones which contain beryllium include beryl and chrysoberyl...
as
startup neutron sourceStartup neutron source is a neutron source used for stable and reliable initiation of nuclear chain reaction in nuclear reactors, when they are loaded with fresh nuclear fuel, whose neutron flux from spontaneous fission is insufficient for a reliable startup, or after prolonged shutdown periods...
s.
Antimony sulfides have been shown to help stabilize the friction coefficient in automotive brake pad materials.
Antimony also is used in the making of bullets and bullet tracers. This element is also used in cosmetics and event paint and glass art crafts.
Precautions
Antimony and many of its compounds are toxic, and the effects of antimony poisoning are similar to
arsenic poisoningArsenic poisoning is a medical condition caused by increased levels of the element arsenic in the body. Arsenic interferes with cellular longevity by allosteric inhibition of an essential metabolic enzyme...
. Inhalation of antimony dust is harmful and in certain cases may be fatal; in small doses, antimony causes
headacheA headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
s,
dizzinessDizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
, and
depressionDepression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
. Larger doses such as prolonged skin contact may cause dermatitis; otherwise it can damage the kidneys and the liver, causing violent and frequent
vomitingVomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
, and will lead to death in a few days.
Antimony is incompatible with strong oxidizing agents, strong acids, halogen acids, chlorine, or fluorine. It should be kept away from heat.
Antimony
leachesLeaching is the process of extracting minerals from a solid by dissolving them in a liquid, either in nature or through an industrial process. In the chemical processing industry, leaching has a variety of commercial applications, including separation of metal from ore using acid, and sugar from...
from
polyethylene terephthalatePolyethylene terephthalate , commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination...
(PET) bottles into liquids. While levels observed for
bottled waterBottled water is drinking water packaged in plastic or glass water bottles. Bottled water may be carbonated or not...
are below
drinking waterDrinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...
guidelines, fruit juice concentrates (for which no guidelines are established) produced in the UK were found to contain up to 44.7 µg/L of antimony, well above the EU limits for
tap waterTap water is a principal component of "indoor plumbing", which became available in urban areas of the developed world during the last quarter of the 19th century, and common during the mid-20th century...
of 5 µg/L. The guidelines are:
- World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
: 20 µg/L
- Japan: 15 µg/L
- United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
, Health Canada and the Ontario Ministry of Environment: 6 µg/L
- German Federal Ministry of Environment: 5 µg/L
See also
- Antimonial
Antimonials, in pre-modern medicine, were remedies principally containing antimony, used chiefly for emetic purposes. They might also have qualified for cathartic, diaphoretic, or simply alterative uses...
- Antimony pill
An Antimony pill is a pill made from metallic antimony. It was a popular remedy in the nineteenth century, and it was used to purge and revitalise the bowels...
- Phase change memory
- Naturalis Historia
The Natural History is an encyclopedia published circa AD 77–79 by Pliny the Elder. It is one of the largest single works to have survived from the Roman Empire to the modern day and purports to cover the entire field of ancient knowledge, based on the best authorities available to Pliny...
- Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...
External links