Antimony trioxide

Last updated
Antimony(III) oxide
Antimony trioxide.jpg
Names
IUPAC name
Antimony(III) oxide
Other names
Antimony sesquioxide
Antimonous oxide
Flowers of Antimony
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.013.796 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 215-474-6
KEGG
PubChem CID
RTECS number
  • CC5650000
UNII
  • InChI=1S/3O.2Sb Yes check.svgY
    Key: ADCOVFLJGNWWNZ-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/3O.2Sb/rO3Sb2/c1-4-3-5-2
    Key: ADCOVFLJGNWWNZ-VTKDZCJOAA
  • O=[Sb]O[Sb]=O
Properties
Sb2O3
Molar mass 291.518 g/mol
Appearancewhite solid
Odor odorless
Density 5.2 g/cm3, α-form
5.67 g/cm3 β-form
Melting point 656 °C (1,213 °F; 929 K)
Boiling point 1,425 °C (2,597 °F; 1,698 K) (sublimes)
370±37 μg/L between 20.8 °C and 22.9 °C
Solubility soluble in acid
−69.4×10−6 cm3/mol
2.087, α-form
2.35, β-form
Structure
cubic (α) < 570 °C
orthorhombic (β) > 570 °C
pyramidal
zero
Hazards
GHS labelling:
GHS-pictogram-silhouette.svg [1]
Warning [1]
H351 [1]
P281 [1]
NFPA 704 (fire diamond)
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
0
0
Lethal dose or concentration (LD, LC):
7000 mg/kg, oral (rat)
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 0.5 mg/m3 (as Sb) [2]
REL (Recommended)
TWA 0.5 mg/m3 (as Sb) [2]
Related compounds
Other anions
Antimony trisulfide
Antimony triselenide
Antimony telluride
Other cations
Dinitrogen trioxide
Phosphorus trioxide
Arsenic trioxide
Bismuth trioxide
Related compounds
Diantimony tetraoxide
Antimony pentoxide
Supplementary data page
Antimony trioxide (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Antimony(III) oxide 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. [3] Like most polymeric oxides, Sb2O3 dissolves in aqueous solutions with hydrolysis. A mixed arsenic-antimony oxide occurs in nature as the very rare mineral stibioclaudetite. [4] [5]

Contents

Production and properties

Global production of antimony(III) oxide in 2012 was 130,000 tonnes, an increase from 112,600 tonnes in 2002. China produces the largest share followed by US/Mexico, Europe, Japan and South Africa and other countries (2%). [6]

As of 2010, antimony(III) oxide was produced at four sites in the EU. It is produced via two routes, re-volatilizing of crude antimony(III) oxide and by oxidation of antimony metal. Oxidation of antimony metal dominates in Europe. Several processes for the production of crude antimony(III) oxide or metallic antimony from virgin material. The choice of process depends on the composition of the ore and other factors. Typical steps include mining, crushing and grinding of ore, sometimes followed by froth flotation and separation of the metal using pyrometallurgical processes (smelting or roasting) or in a few cases (e.g. when the ore is rich in precious metals) by hydrometallurgical processes. These steps do not take place in the EU but closer to the mining location.

Re-volatilizing of crude antimony(III) oxide

Step 1) Crude stibnite is oxidized to crude antimony(III) oxide using furnaces operating at approximately 500 to 1,000 °C. The reaction is the following:

2 Sb2S3 + 9 O2 → 2 Sb2O3 + 6 SO2

Step 2) The crude antimony(III) oxide is purified by sublimation.

Oxidation of antimony metal

Antimony metal is oxidized to antimony(III) oxide in furnaces. The reaction is exothermic. Antimony(III) oxide is formed through sublimation and recovered in bag filters. The size of the formed particles is controlled by process conditions in furnace and gas flow. The reaction can be schematically described by:

4 Sb + 3 O2 → 2 Sb2O3

Properties

Antimony(III) oxide is an amphoteric oxide. It dissolves in aqueous sodium hydroxide solution to give the meta-antimonite NaSbO2, which can be isolated as the trihydrate. Antimony(III) oxide also dissolves in concentrated mineral acids to give the corresponding salts, which hydrolyzes upon dilution with water. [7] With nitric acid, the trioxide is oxidized to antimony(V) oxide. [8]

When heated with carbon, the oxide is reduced to antimony metal. With other reducing agents such as sodium borohydride or lithium aluminium hydride, the unstable and very toxic gas stibine is produced. [9] When heated with potassium bitartrate, a complex salt potassium antimony tartrate, KSb(OH)2·C4H2O6, is formed. [8]

Structure

The structure of Sb2O3 depends on the temperature of the sample. Dimeric Sb4O6 is the high temperature (1560 °C) gas. [10] Sb4O6 molecules are bicyclic cages, similar to the related oxide of phosphorus(III), phosphorus trioxide. [11] The cage structure is retained in a solid that crystallizes in a cubic habit. The Sb–O distance is 197.7 pm and the O–Sb–O angle of 95.6°. [12] This form exists in nature as the mineral senarmontite. [11] Above 606 °C, the more stable form is orthorhombic, consisting of pairs of -Sb-O-Sb-O- chains that are linked by oxide bridges between the Sb centers. This form exists in nature as the mineral valentinite. [11]

Sb4O6-molecule-from-senarmontite-xtal-2004-3D-balls-B.png Antimony(III)-oxide-senarmontite-xtal-2004-3D-balls.png Antimony(III)-oxide-valentinite-xtal-2004-3D-balls.png
Sb4O6senarmontitevalentinite

Uses

The annual consumption of antimony(III) oxide in the United States and Europe is approximately 10,000 and 25,000 tonnes, respectively. The main application is as flame retardant synergist in combination with halogenated materials. The combination of the halides and the antimony is key to the flame-retardant action for polymers, helping to form less flammable chars. Such flame retardants are found in electrical apparatuses, textiles, leather, and coatings. [13]

Other applications:

Safety

Antimony(III) oxide has suspected carcinogenic potential for humans. [13] Its TLV is 0.5 mg/m3, as for most antimony compounds. [14] Before 2021, no other human health hazards were identified for antimony(III) oxide, and no risks to human health and the environment were identified from the production and use of antimony trioxide in daily life. However, the 15th Report on Carcinogens released on December 21, 2021, by the US Department of Health and Human Services categorised antimony(III) oxide as carcinogenic. [15]

Related Research Articles

<span class="mw-page-title-main">Antimony</span> Chemical element with atomic number 51 (Sb)

Antimony is a chemical element; it has symbol Sb (from Latin stibium) and atomic number 51. A lustrous grey metal or metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name kohl. The earliest known description of the metalloid in the West was written in 1540 by Vannoccio Biringuccio.

A metalloid is a chemical element which has a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals. There is no standard definition of a metalloid and no complete agreement on which elements are metalloids. Despite the lack of specificity, the term remains in use in the literature.

<span class="mw-page-title-main">Pnictogen</span> Group 15 elements of the periodic table with valency 5

A pnictogen is any of the chemical elements in group 15 of the periodic table. Group 15 is also known as the nitrogen group or nitrogen family. Group 15 consists of the elements nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and moscovium (Mc).

<span class="mw-page-title-main">Arsine</span> Chemical compound

Arsine (IUPAC name: arsane) is an inorganic compound with the formula AsH3. This flammable, pyrophoric, and highly toxic pnictogen hydride gas is one of the simplest compounds of arsenic. Despite its lethality, it finds some applications in the semiconductor industry and for the synthesis of organoarsenic compounds. The term arsine is commonly used to describe a class of organoarsenic compounds of the formula AsH3−xRx, where R = aryl or alkyl. For example, As(C6H5)3, called triphenylarsine, is referred to as "an arsine".

In chemistry, antimonite refers to a salt of antimony(III), such as NaSb(OH)4 and NaSbO2 (meta-antimonite), which can be prepared by reacting alkali with antimony trioxide, Sb2O3. These are formally salts of antimonous acid, Sb(OH)3, whose existence in solution is dubious. Attempts to isolate it generally form Sb2O3·xH2O, antimony(III) oxide hydrate, which slowly transforms into Sb2O3.

<span class="mw-page-title-main">Chromate and dichromate</span> Chromium(VI) anions

Chromate salts contain the chromate anion, CrO2−
4
. Dichromate salts contain the dichromate anion, Cr
2
O2−
7
. They are oxyanions of chromium in the +6 oxidation state and are moderately strong oxidizing agents. In an aqueous solution, chromate and dichromate ions can be interconvertible.

<span class="mw-page-title-main">Antimony trisulfide</span> Chemical compound

Antimony trisulfide is found in nature as the crystalline mineral stibnite and the amorphous red mineral metastibnite. It is manufactured for use in safety matches, military ammunition, explosives and fireworks. It also is used in the production of ruby-colored glass and in plastics as a flame retardant. Historically the stibnite form was used as a grey pigment in paintings produced in the 16th century. In 1817, the dye and fabric chemist, John Mercer discovered the non-stoichiometric compound Antimony Orange, the first good orange pigment available for cotton fabric printing.

<span class="mw-page-title-main">Valentinite</span>

Valentinite is an antimony oxide mineral with formula Sb2O3. Valentinite crystallizes in the orthorhombic system and typically forms as radiating clusters of euhedral crystals or as fibrous masses. It is colorless to white with occasional shades or tints of yellow and red. It has a Mohs hardness of 2.5 to 3 and a specific gravity of 5.76. Valentinite occurs as a weathering product of stibnite and other antimony minerals. It is dimorphous with the isometric antimony oxide senarmontite.

<span class="mw-page-title-main">Chromium trioxide</span> Chemical compound

Chromium trioxide is an inorganic compound with the formula CrO3. It is the acidic anhydride of chromic acid, and is sometimes marketed under the same name. This compound is a dark-purple solid under anhydrous conditions and bright orange when wet. The substance dissolves in water accompanied by hydrolysis. Millions of kilograms are produced annually, mainly for electroplating. Chromium trioxide is a powerful oxidiser, a mutagen, and a carcinogen.

<span class="mw-page-title-main">Stibine</span> Chemical compound

Stibine (IUPAC name: stibane) is a chemical compound with the formula SbH3. A pnictogen hydride, this colourless, highly toxic 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 170.7 pm (1.707 Å). The smell of this compound from usual sources (like from reduction of antimony compounds) is reminiscent of arsine, id est garlic-like.

<span class="mw-page-title-main">Vanadium(V) oxide</span> Precursor to vanadium alloys and industrial catalyst

Vanadium(V) oxide (vanadia) is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the industrial perspective, it is the most important compound of vanadium, being the principal precursor to alloys of vanadium and is a widely used industrial catalyst.

Antimony pentafluoride is the inorganic compound with the formula SbF5. This colourless, viscous liquid is a strong Lewis acid and a component of the superacid fluoroantimonic acid, formed upon mixing liquid HF with liquid SbF5 in 1:1 ratio. It is notable for its strong Lewis acidity and the ability to react with almost all known compounds.

<span class="mw-page-title-main">Arsenic pentoxide</span> Chemical compound

Arsenic pentoxide is the inorganic compound with the formula As2O5. This glassy, white, deliquescent solid is relatively unstable, consistent with the rarity of the As(V) oxidation state. More common, and far more important commercially, is arsenic(III) oxide (As2O3). All inorganic arsenic compounds are highly toxic and thus find only limited commercial applications.

<span class="mw-page-title-main">Antimony tribromide</span> Chemical compound

Antimony tribromide (SbBr3) is a chemical compound containing antimony in its +3 oxidation state.

Selenium trioxide is the inorganic compound with the formula SeO3. It is white, hygroscopic solid. It is also an oxidizing agent and a Lewis acid. It is of academic interest as a precursor to Se(VI) compounds.

<span class="mw-page-title-main">Antimony trifluoride</span> Chemical compound

Antimony trifluoride is the inorganic compound with the formula SbF3. Sometimes called Swarts' reagent, it is one of two principal fluorides of antimony, the other being SbF5. It appears as a white solid. As well as some industrial applications, it is used as a reagent in inorganic and organofluorine chemistry.

Organoarsenic chemistry is the chemistry of compounds containing a chemical bond between arsenic and carbon. A few organoarsenic compounds, also called "organoarsenicals," are produced industrially with uses as insecticides, herbicides, and fungicides. In general these applications are declining in step with growing concerns about their impact on the environment and human health. The parent compounds are arsane and arsenic acid. Despite their toxicity, organoarsenic biomolecules are well known.

<span class="mw-page-title-main">Antimony tetroxide</span> Chemical compound

Antimony tetroxide is an inorganic compound with the formula Sb2O4. This material, which exists as the mineral cervantite, is white but reversibly yellows upon heating. The material, with empirical formula SbO2, is called antimony tetroxide to signify the presence of two kinds of Sb centers.

<span class="mw-page-title-main">Antimony(III) sulfate</span> Chemical compound

Antimony sulfate, Sb2(SO4)3, is a hygroscopic salt formed by reacting antimony or its compounds with hot sulfuric acid. It is used in doping of semiconductors and in the production of explosives and fireworks.

In chemistry, molecular oxohalides (oxyhalides) are a group of chemical compounds in which both oxygen and halogen atoms are attached to another chemical element A in a single molecule. They have the general formula AOmXn, where X is a halogen. Known oxohalides have fluorine (F), chlorine (Cl), bromine (Br), and/or iodine (I) in their molecules. The element A may be a main group element, a transition element, a rare earth element or an actinide. The term oxohalide, or oxyhalide, may also refer to minerals and other crystalline substances with the same overall chemical formula, but having an ionic structure.

References

  1. 1 2 3 4 Record of Antimony trioxide in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 23 August 2017.
  2. 1 2 NIOSH Pocket Guide to Chemical Hazards. "#0036". National Institute for Occupational Safety and Health (NIOSH).
  3. Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. ISBN   0-7506-3365-4.
  4. "Stibioclaudetite".
  5. "List of Minerals". 21 March 2011.
  6. European Union Risk Assessment Report: DIANTIMONY TRIOXIDE (draft) (PDF) (Report). Sweden. November 2008. CAS No: 1309-64-4; EINECS No: 215-175-0. Archived from the original (PDF) on 2014-01-06.
  7. Housecroft, C. E.; Sharpe, A. G. (2008). "Chapter 15: The group 15 elements". Inorganic Chemistry (3rd ed.). Pearson. p. 481. ISBN   978-0-13-175553-6.
  8. 1 2 Patnaik, P. (2002). Handbook of Inorganic Chemicals. McGraw-Hill. p. 56. ISBN   0-07-049439-8.
  9. Bellama, J. M.; MacDiarmid, A. G. (1968). "Synthesis of the Hydrides of Germanium, Phosphorus, Arsenic, and Antimony by the Solid-Phase Reaction of the Corresponding Oxide with Lithium Aluminum Hydride". Inorganic Chemistry . 7 (10): 2070–2072. doi:10.1021/ic50068a024.
  10. Wiberg, E.; Holleman, A. F. (2001). Inorganic Chemistry. Elsevier. ISBN   0-12-352651-5.
  11. 1 2 3 Wells, A. F. (1984). Structural Inorganic Chemistry. Oxford: Clarendon Press. ISBN   0-19-855370-6.
  12. Svensson, C. (1975). "Refinement of the crystal structure of cubic antimony(III) oxide, Sb2O3". Acta Crystallographica B. 31 (8): 2016–2018. doi:10.1107/S0567740875006759.
  13. 1 2 Grund, S. C.; Hanusch, K.; Breunig, H. J.; Wolf, H. U. "Antimony and Antimony Compounds". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a03_055.pub2. ISBN   978-3527306732.
  14. Newton, P. E.; Schroeder, R. E.; Zwick, L.; Serex, T. (2004). "Inhalation Developmental Toxicity Studies In Rats With Antimony(III) oxide (Sb2O3)". Toxicologist. 78 (1–S): 38.
  15. "15th Report on Carcinogens". National Toxicology Program. Retrieved 2023-06-15.

Further reading