Aluminium silicate: Difference between revisions

{{About|neutral chemical compounds composed solely of aluminium, silicon, and oxygen|related charged compounds containing counterions|Aluminosilicate}}

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 457807899

| ImageFile = Aluminium silicate.JPG

| Section1 = {{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 12141-46-7

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = T1FAD4SS2M

| PubChem = 10313254

| ChemSpiderID = 8488719

| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}

| SMILES = O=[Al]O[Si](=O)O[Al]=O

| StdInChI = 1S/2Al.O3Si.2O/c;;1-4(2)3;;/q2*+1;-2;;

| StdInChI_Ref = {{stdinchicite|changed|chemspider}}

| StdInChIKey = PZZYQPZGQPZBDN-UHFFFAOYSA-N

| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}

| Section2 = {{Chembox Properties

| Formula = {{Chem|Al|2|SiO|5}}

| MolarMass = 162.0456 g mol⁻¹

'''Aluminum silicate''' (or '''aluminium silicate''') is a name commonly applied to chemical compounds which are derived from [[aluminium oxide]], Al₂O₃ and [[silicon dioxide]], SiO₂ which may be [[anhydrous]] or hydrated, naturally occurring as [[mineral]]s or synthetic. Their chemical formulae are often expressed as xAl₂O₃·ySiO₂·zH₂O. It is known as [[E number]] '''E559'''.

==Main representatives==

{{al2sio5 phase diagram}}

[[Andalusite]], [[kyanite]], and [[sillimanite]] are the principal aluminium silicate minerals.<ref>{{cite web|url=http://rruff.geo.arizona.edu/doclib/hom/andalusite.pdf|title=Andalusite, Handbook of Mineralogy|url-status=live|archive-url=https://web.archive.org/web/20120516011115/http://rruff.geo.arizona.edu/doclib/hom/andalusite.pdf|archive-date=2012-05-16}}</ref><ref>{{cite web|url=http://rruff.geo.arizona.edu/doclib/hom/kyanite.pdf|title=Kyanite |work=Handbook of Mineralogy|url-status=live|archive-url=https://web.archive.org/web/20120224015145/http://rruff.geo.arizona.edu/doclib/hom/kyanite.pdf|archive-date=2012-02-24}}</ref><ref>{{cite web|url=http://rruff.geo.arizona.edu/doclib/hom/sillimanite.pdf|title=Sillimanite |work=Handbook of Mineralogy |url-status=live|archive-url=https://web.archive.org/web/20111119233945/http://rruff.geo.arizona.edu/doclib/hom/sillimanite.pdf|archive-date=2011-11-19}}</ref> The [[triple point]] of the three [[Polymorphism (materials science)|polymorphs]] is located at a temperature of {{convert|500|°C}} and a pressure of {{convert|0.4|GPa|abbr=on}}. These three minerals are commonly used as [[index mineral]]s in [[metamorphic rock]]s.

* Al₂SiO₅, (Al₂O₃·SiO₂), which occurs naturally as the minerals [[andalusite]], [[kyanite]] and [[sillimanite]] which have distinct crystal structures.

* Al₂Si₂O₇, (Al₂O₃·2SiO₂), called metakaolinite, formed from kaolin by heating at {{convert|450|C}}.<ref name="Perry" />

* Al₆Si₂O₁₃, (3Al₂O₃·2SiO₂), the mineral [[mullite]], the only thermodynamically stable intermediate phase in the Al₂O₃-SiO₂ system at atmospheric pressure.<ref name = "Shackelford">Ceramic and Glass Materials: Structure, Properties and Processing, James F. Shackelford, R. H. Doremus, Springer, 2008, {{ISBN|978-0-387-73361-6}}</ref> This also called '3:2 mullite' to distinguish it from 2Al₂O₃·SiO₂, Al₄SiO₈ '2:1 mullite'.

* 2Al₂O₃·SiO₂, Al₄SiO₈ '2:1 mullite'.<ref name="Shackelford" />

The above list mentions [[ternary phase|ternary material]]s (Si-Al-O). [[Kaolinite]] is a quaternary material (Si-Al-O-H). Also called aluminium silicate dihydrate, kaolinite occurs naturally as a mineral. Its formula is Al₂Si₂O₅(OH)₄, (Al₂O₃·2SiO₂·2H₂O).<ref name = "Perry">Handbook of Inorganic Compounds, Dale L. Perry, Taylor & Francis, 2011, {{ISBN|978-1-4398-1461-1}}</ref>

==Aluminium silicate composite materials, fibres==

Aluminium silicate is a type of fibrous material made of aluminium oxide and silicon dioxide, (such materials are also called aluminosilicate fibres). These are glassy solid solutions rather than chemical compounds. The compositions are often described in terms of % weight of [[alumina]], Al₂O₃ and [[silica]], SiO₂. Temperature resistance increases as the % alumina increases. These fibrous materials can be encountered as loose wool, blanket, felt, paper or boards.<ref>Concise Encyclopedia of Composite Materials, ed. Anthony Kelly, MIT Press, 1989, {{ISBN|0-262-11145-4}}</ref>

{{Reflist}}

*[https://web.archive.org/web/20120202185948/http://www.science.uwaterloo.ca/~cchieh/cact/applychem/alsilicate.html Aluminum silicates] at the University of Waterloo, Canada

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[[Category:Aluminium compounds|Silicates]]

[[Category:Silicates]]

[[Category:Orthorhombic minerals]]

[[Category:E-number additives]]