Editing Ilmenite

{{Short description|Titanium-iron oxide mineral}}
{{Use dmy dates|date=April 2022}}
{{Infobox mineral
| name        = Ilmenite
| category    = [[Oxide mineral]]
| boxwidth    = 
| boxbgcolor  = 
| image       = Ilmenite-155036.jpg
| imagesize   = 
| caption     = Ilmenite from Miass, Ilmen Mts, Chelyabinsk Oblast', Southern Urals, Urals Region, Russia. 4.5 x 4.3 x 1.5 cm
| formula     = Iron titanium oxide, {{Chem|Fe||Ti||O|3}}
| IMAsymbol   = Ilm<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref>
| strunz      = 4.CB.05
| dana        = 04.03.05.01
| system      = [[Trigonal]]
| class       = Rhombohedral ({{overline|3}}) <br/>[[H-M symbol]]: ({{overline|3}})
| symmetry    = ''R''{{overline|3}} (no. 148)
| unit cell   = a = 5.08854(7) <br/>c = 14.0924(3)&nbsp;[Å]: Z&nbsp;=&nbsp;6
| color       = Iron-black; gray with a brownish tint in reflected light
| habit       = Granular to massive and lamellar exsolutions in hematite or magnetite
| twinning    = {0001} simple, {10{{overline|1}}1} lamellar
| cleavage    = Absent; parting on {0001} and {10{{overline|1}}1}
| fracture    = [[Conchoidal fracture|Conchoidal]] to subconchoidal
| tenacity    = Brittle
| mohs        = 5–6
| luster      = Metallic to submetallic
| refractive  = 
| opticalprop = Uniaxial (–)
| birefringence = Strong; O: pinkish brown, E: dark brown (bireflectance)
| pleochroism = 
| streak      = Black
| gravity     = 4.70–4.79
| density     = 
| melt        = 
| fusibility  = 
| diagnostic  = 
| solubility  = 
| diaphaneity = Opaque
| other       = Weakly magnetic
| references  = <ref>{{cite web |last1=Barthelmy |first1=David |title=Ilmenite Mineral Data |url=http://webmineral.com/data/Ilmenite.shtml |website=Mineralogy Database |publisher=Webmineral.com |access-date=12 February 2022 |date=2014}}</ref><ref name=HBM>{{cite book |editor-first1=John W. |editor-last1=Anthony |editor-first2=Richard A. |editor-last2=Bideaux |editor-first3=Kenneth W. |editor-last3=Bladh |editor-first4=Monte C. |editor-last4=Nichols |title=Handbook of Mineralogy |publisher=Mineralogical Society of America |location=Chantilly, VA, USA |url=http://rruff.geo.arizona.edu/doclib/hom/ilmenite.pdf |access-date=12 February 2022 |chapter=Ilmenite}}</ref><ref name=Mindat>{{mindat|id=2013|name=ilmenite}}</ref>
}}

'''Ilmenite''' is a titanium-iron [[oxide mineral]] with the idealized formula {{Chem|Fe||Ti||O|3}}. It is a weakly magnetic black or steel-gray solid.  Ilmenite is the most important ore of [[titanium]]<ref>Heinz Sibum, Volker Günther, Oskar Roidl, Fathi Habashi, Hans Uwe Wolf, "Titanium, Titanium Alloys, and Titanium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry 2005, Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a27_095}}</ref> and the main source of [[titanium dioxide]], which is used in paints, printing inks,<ref>{{Cite web|url=http://www.sanbohk.com/uploadfiles/2014-2/2014211105416156.pdf|title=Sachtleben RDI-S|access-date=2018-12-25|archive-date=2018-12-25|archive-url=https://web.archive.org/web/20181225130335/http://www.sanbohk.com/uploadfiles/2014-2/2014211105416156.pdf|url-status=dead}}</ref> fabrics, plastics, paper, sunscreen, food and cosmetics.<ref>{{Cite web|url=http://www.mineralcommodities.com/products/|title=Products|website=Mineral Commodities Ltd|access-date=2016-08-08}}</ref>

== Structure and properties ==
Ilmenite is a heavy (specific gravity 4.7), moderately hard (Mohs hardness 5.6 to 6), opaque black mineral with a submetallic luster.<ref name=KleinHurlbut1993/> It is almost always massive, with thick tabular crystals being quite rare. It shows no discernible cleavage, breaking instead with a conchoidal to uneven fracture.<ref name=Sinkankas1964/>

Ilmenite crystallizes in the [[trigonal]] system with space group ''R''{{overline|3}}.<ref name=Nesse2000>{{cite book |last1=Nesse |first1=William D. |title=Introduction to mineralogy |date=2000 |publisher=Oxford University Press |location=New York |isbn=9780195106916 |pages=366–367}}</ref><ref name=HBM/> The ilmenite [[crystal structure]] consists of an ordered derivative of the [[corundum]] structure; in corundum all cations are identical but in ilmenite Fe<sup>2+</sup> and Ti<sup>4+</sup> ions occupy alternating layers perpendicular to the trigonal c axis.

Pure ilmenite is [[paramagnetic]] (showing only very weak attraction to a magnet), but ilmenite forms [[solid solution]]s with [[hematite]] that are weakly [[ferromagnetic]] and so are noticeably attracted to a magnet. Natural deposits of ilmenite usually contain intergrown or exsolved [[magnetite]] that also contribute to its ferromagnetism.<ref name=KleinHurlbut1993>{{cite book |last1=Klein |first1=Cornelis |last2=Hurlbut |first2=Cornelius S. Jr. |title=Manual of mineralogy : (after James D. Dana) |date=1993 |publisher=Wiley |location=New York |isbn=047157452X |edition=21st |pages=380–381}}</ref>

Ilmenite is distinguished from hematite by its less intensely black color and duller appearance and its black [[Streak (mineralogy)|streak]], and from magnetite by its weaker magnetism.<ref name=Sinkankas1964>{{cite book |last1=Sinkankas |first1=John |title=Mineralogy for amateurs. |date=1964 |publisher=Van Nostrand |location=Princeton, N.J. |isbn=0442276249 |pages=328–329}}</ref><ref name=KleinHurlbut1993/>

<gallery>

Image:Ilmenite.GIF|Crystal structure of ilmenite
File:Ilmenite-65675.jpg|Ilmenite from Froland, Aust-Agder, Norway; 4.1 × 4.1 × 3.8&nbsp;cm
File:Ilmenite and hematite under normal light.jpg|Ilmenite and hematite under normal light
File:Ilmenite and hematite under polarized light.jpg|Ilmenite and hematite under polarized light
</gallery>

==Discovery==
In 1791 [[William Gregor]] discovered a deposit of black sand in a stream that runs through the valley just south of the village of [[Manaccan]] ([[Cornwall]]), and identified for the first time titanium as one of the constituents of the main mineral in the sand.<ref>Gregor, William (1791) "Beobachtungen und Versuche über den Menakanit, einen in Cornwall gefundenen magnetischen Sand" (Observations and experiments regarding menaccanite [i.e., ilmenite], a magnetic sand found in Cornwall), ''Chemische Annalen'' …, '''1''', [https://books.google.com/books?id=ZFAyAQAAMAAJ&pg=PA40 pp. 40–54], [https://books.google.com/books?id=ZFAyAQAAMAAJ&pg=PA103 103–119.]</ref><ref>{{cite book|title=Nature's Building Blocks: An A-Z Guide to the Elements|last1=Emsley|first1=John|publisher=Oxford University Press|year=2001|location=Oxford, England, UK|isbn=978-0-19-850340-8 |chapter=Titanium |chapter-url=https://books.google.com/books?id=j-Xu07p3cKwC|url-access=registration|url=https://archive.org/details/naturesbuildingb0000emsl}}</ref><ref>{{cite book |last1=Woodford |first1=Chris|author1-link=Chris Woodford (author) |title=Titanium |date=2003 |publisher=Benchmark Books |location=New York |isbn=9780761414612 |page=7 |url=https://books.google.com/books?id=84W_FvfskTsC&dq=history+of+titanium&pg=PA4 |access-date=22 February 2022}}</ref> Gregor named this mineral '''''manaccanite'''''.<ref>{{cite journal |last1=Habashi |first1=Fathi |title=Historical Introduction to Refractory Metals |journal=Mineral Processing and Extractive Metallurgy Review |date=January 2001 |volume=22 |issue=1 |pages=25–53 |doi=10.1080/08827509808962488|bibcode=2001MPEMR..22...25H |s2cid=100370649 }}</ref> The same mineral was found in the [[Ilmensky Mountains]], near [[Miass]], [[Russia]], and named ''ilmenite''.<ref name=Sinkankas1964/>

== Mineral chemistry ==
Pure ilmenite has the composition {{chem2|FeTiO3}}. However, ilmenite most often contains appreciable quantities of magnesium and manganese and up to 6 [[wt%]] of hematite, {{chem2|Fe2O3}}, substituting for {{chem2|FeTiO3}} in the crystal structure. Thus the full chemical formula can be expressed as {{chem2|(Fe,Mg,Mn,Ti)O3}}.<ref name=KleinHurlbut1993/> Ilmenite forms a solid solution with [[geikielite]] ({{Chem|Mg||Ti||O|3}}) and [[pyrophanite]] ({{Chem|Mn||Ti||O|3}}) which are magnesian and manganiferous end-members of the solid solution series.<ref name=HBM/>

Although ilmenite is typically close to the ideal {{Chem|Fe||Ti||O|3}} composition, with minor mole percentages of Mn and Mg,<ref name=HBM/> the ilmenites of [[kimberlite]]s usually contain substantial amounts of geikielite molecules,<ref>{{cite journal |last1=Wyatt |first1=Bruce A. |last2=Baumgartner |first2=Mike |last3=Anckar |first3=Eva |last4=Grutter |first4=Herman |title=Compositional classification of "kimberlitic" and "non-kimberlitic" ilmenite |journal=Lithos |date=September 2004 |volume=77 |issue=1–4 |pages=819–840 |doi=10.1016/j.lithos.2004.04.025|bibcode=2004Litho..77..819W |s2cid=140539776 }}</ref> and in some highly differentiated [[felsic]] rocks ilmenites may contain significant amounts of pyrophanite molecules.<ref name=SasakiEtal2003>{{cite journal |last1=Sasaki |first1=Kazuhiro |last2=Nakashima |first2=Kazuo |last3=Kanisawa |first3=Satoshi |title=Pyrophanite and high Mn ilmenite discovered in the Cretaceous Tono pluton, NE Japan |journal=Neues Jahrbuch für Mineralogie - Monatshefte |date=15 July 2003 |volume=2003 |issue=7 |pages=302–320 |doi=10.1127/0028-3649/2003/2003-0302}}</ref>

At temperatures above {{convert|950|C||sp=us}}, there is a complete solid solution between ilmenite and hematite. There is a [[miscibility gap]] at lower temperatures, resulting in a coexistence of these two minerals in rocks but no solid solution.<ref name=KleinHurlbut1993/> This coexistence may result in exsolution lamellae in cooled ilmenites with more iron in the system than can be homogeneously accommodated in the crystal lattice.<ref>{{cite journal |last1=Weibel |first1=Rikke |last2=Friis |first2=Henrik |title=Chapter 10 Alteration of Opaque Heavy Minerals as a Reflection of the Geochemical Conditions in Depositional and Diagenetic Environments |journal=Developments in Sedimentology |date=2007 |volume=58 |pages=277–303 |doi=10.1016/S0070-4571(07)58010-6|bibcode=2007DevS...58..277W |isbn=9780444517531 }}</ref> Ilmenite containing 6 to 13 percent {{chem2|Fe2O3}} is sometimes described as ''ferrian ilmenite''.<ref name=BuddingtonLindsley1964>{{cite journal |last1=Buddington |first1=A. F. |last2=Lindsley |first2=D. H. |title=Iron-Titanium Oxide Minerals and Synthetic Equivalents |journal=Journal of Petrology |date=1 January 1964 |volume=5 |issue=2 |pages=310–357 |doi=10.1093/petrology/5.2.310}}</ref><ref name=MurphyFrick2006>{{cite book |last1=Murphy |first1=P. |last2=Frick |first2=L. |year=2006 |chapter=Titanium |title=Industrial minerals & rocks: commodities, markets, and uses |editor-last1=Kogel |editor-first1=J. |publisher=SME |pages=987–1003 |isbn=9780873352338 |url=https://books.google.com/books?id=zNicdkuulE4C&q=Titanium |access-date=21 February 2022}}</ref>

Ilmenite [[Metasomatism|alters]] or [[Weathering|weathers]] to form the pseudo-mineral [[leucoxene]], a fine-grained yellowish to grayish or brownish material<ref name=KleinHurlbut1993/><ref>{{cite journal |last1=Mücke |first1=A. |last2=Bhadra Chaudhuri |first2=J.N. |title=The continuous alteration of ilmenite through pseudorutile to leucoxene |journal=Ore Geology Reviews |date=February 1991 |volume=6 |issue=1 |pages=25–44 |doi=10.1016/0169-1368(91)90030-B|bibcode=1991OGRv....6...25M }}</ref> enriched to 70% or more of {{chem2|TiO2}}.<ref name=MurphyFrick2006/> Leucoxene is an important source of titanium in [[heavy mineral sands ore deposits]].<ref name="VanGosenEtal2014">{{cite journal |last1=Van Gosen |first1=Bradley S. |last2=Fey |first2=David L. |last3=Shah |first3=Anjana K. |last4=Verplanck |first4=Philip L. |last5=Hoefen |first5=Todd M. |title=Deposit model for heavy-mineral sands in coastal environments |journal=U.S. Geological Survey Scientific Investigations Report |series=Scientific Investigations Report |date=2014 |volume=201--5070-L |page=13 |doi=10.3133/sir20105070L|doi-access=free |bibcode=2014usgs.rept...13V }}</ref>

== Paragenesis ==
Ilmenite is a common accessory mineral found in [[metamorphic rock|metamorphic]] and [[igneous rock]]s.<ref name=HBM/> It is found in large concentrations in [[layered intrusion]]s where it forms as part of a [[cumulate rock|cumulate]] layer within the intrusion. Ilmenite generally occurs in these cumulates together with [[orthopyroxene]]<ref>{{cite journal |last1=Wilson |first1=J.R. |last2=Robins |first2=B. |last3=Nielsen |first3=F.M. |last4=Duchesne |first4=J.C. |last5=Vander Auwera |first5=J. |title=The Bjerkreim-Sokndal Layered Intrusion, Southwest Norway |journal=Developments in Petrology |date=1996 |volume=15 |pages=231–255 |doi=10.1016/S0167-2894(96)80009-1|bibcode=1996DevPe..15..231W |hdl=2268/550 |isbn=9780444817686 |hdl-access=free }}</ref> or in combination with [[plagioclase]] and [[apatite]] (''[[nelsonite]]'').<ref>{{cite journal |last1=Charlier |first1=Bernard |last2=Sakoma |first2=Emmanuel |last3=Sauvé |first3=Martin |last4=Stanaway |first4=Kerry |last5=Auwera |first5=Jacqueline Vander |last6=Duchesne |first6=Jean-Clair |title=The Grader layered intrusion (Havre-Saint-Pierre Anorthosite, Quebec) and genesis of nelsonite and other Fe–Ti–P ores |journal=Lithos |date=March 2008 |volume=101 |issue=3–4 |pages=359–378 |doi=10.1016/j.lithos.2007.08.004|bibcode=2008Litho.101..359C |hdl=2268/1893 |hdl-access=free }}</ref>

[[Magnesium|Magnesian]] ilmenite is formed in kimberlites as part of the MARID association of minerals ([[mica]]-[[amphibole]]-[[rutile]]-ilmenite-[[diopside]]) assemblage of [[Biotite|glimmerite]] [[xenolith]]s.<ref>{{cite journal |last1=Dawson |first1=J.Barry |last2=Smith |first2=Joseph V. |title=The MARID (mica-amphibole-rutile-ilmenite-diopside) suite of xenoliths in kimberlite |journal=Geochimica et Cosmochimica Acta |date=February 1977 |volume=41 |issue=2 |pages=309–323 |doi=10.1016/0016-7037(77)90239-3|bibcode=1977GeCoA..41..309D |doi-access=free }}</ref> [[Manganese|Manganiferous]] ilmenite is found in [[granite|granitic]] rocks<ref name=SasakiEtal2003/> and also in [[carbonatite]] intrusions where it may also contain anomalously high amounts of [[niobium]].<ref>{{cite journal |last1=Cordeiro |first1=Pedro F.O. |last2=Brod |first2=José A. |last3=Dantas |first3=Elton L. |last4=Barbosa |first4=Elisa S.R. |title=Mineral chemistry, isotope geochemistry and petrogenesis of niobium-rich rocks from the Catalão I carbonatite-phoscorite complex, Central Brazil |journal=Lithos |date=August 2010 |volume=118 |issue=3–4 |pages=223–237 |doi=10.1016/j.lithos.2010.04.007|bibcode=2010Litho.118..223C }}</ref>

Many [[mafic]] igneous rocks contain grains of intergrown magnetite and ilmenite, formed by the [[oxidation]] of [[ulvospinel]].<ref name="BuddingtonLindsley1964"/>

== Processing and consumption ==
[[File:Tellnes.jpg|thumb|300px|Tellnes opencast ilmenite mine, [[Sokndal]], Norway]]

Most ilmenite is mined for [[titanium dioxide]] production.<ref>{{Cite web|url=http://www.mineralcommodities.com/products/industry-fundamentals/|title=Industry Fundamentals|website=Mineral Commodities Ltd|access-date=2016-08-08|archive-date=2016-10-07|archive-url=https://web.archive.org/web/20161007145819/http://www.mineralcommodities.com/products/industry-fundamentals/|url-status=dead}}</ref> Ilmenite and titanium dioxide are used in the production of [[titanium]] metal.<ref>{{Cite journal|last=Kroll|first=W|title=The production of ductile titanium|journal= Transactions of the Electrochemical Society|volume=78|pages=35–47|doi=10.1149/1.3071290|year=1940}}</ref><ref>{{Cite journal|last=Seki|first=Ichiro|title=Reduction of titanium dioxide to metallic titanium by nitridization and thermal decomposition|url=https://www.jstage.jst.go.jp/article/matertrans/58/3/58_MK201601/_pdf|journal=Materials Transactions|volume=58|issue= 3|pages=361–366|doi=10.2320/matertrans.MK201601|year=2017|doi-access=free}}</ref>

Titanium dioxide is most used as a white pigment and the major consuming industries for TiO<sub>2</sub>  pigments are paints and surface coatings, plastics, and paper and paperboard. Per capita consumption of TiO<sub>2</sub> in China is about 1.1 kilograms per year, compared with 2.7 kilograms for Western Europe and the United States.<ref>{{Cite web|url=https://ihsmarkit.com/products/titanium-dioxide-chemical-economics-handbook.html|title=Titanium Dioxide Chemical Economics Handbook}}</ref>

[[File:Estimated world production of titanium concentrate by mineral source in metric tons, 2015–2019.png|thumb|Estimated world production of titanium concentrate by mineral source in metric tons, 2015–2019. Titanium concentrate is mainly obtained from processing of ilmenite mineral, followed by titaniferous slags and natural rutile.]]

Titanium is the ninth most abundant element on Earth and represents about 0.6 percent of the Earth's crust. Ilmenite is commonly processed to obtain a titanium concentrate, which is called "synthetic rutile" if it contains more than 90 percent TiO2, or more generally "titaniferous slags" if it has a lower TiO2 content. More than 80 percent of the estimated global production of titanium concentrate is obtained from the processing of ilmenite, while 13 percent is obtained from titaniferous slags and 5 percent from rutile.<ref name=":0">{{Cite web |title=Patent Landscape Report |url=https://www.wipo.int/publications/en/details.jsp?id=4651&plang=EN |access-date=2023-10-19 |website=[[WIPO]] |doi=10.34667/tind.47029 |language=en |author1=World Intellectual Property Organization. |series=Patent Landscape Reports |date=2023 }}</ref>

Ilmenite can be converted into pigment grade titanium dioxide  via either the sulfate process or the [[chloride process]].<ref name=Ullmann>{{Ullmann|author=Völz, Hans G. |display-authors=etal |title=Pigments, Inorganic|year=2006|doi=10.1002/14356007.a20_243.pub2}}</ref> Ilmenite can also be improved and purified to titanium dioxide in the form of rutile using the [[Becher process]].<ref>{{cite journal |last1=Welham |first1=N.J. |title=A parametric study of the mechanically activated carbothermic reduction of ilmenite |journal=Minerals Engineering |date=December 1996 |volume=9 |issue=12 |pages=1189–1200 |doi=10.1016/S0892-6875(96)00115-X|bibcode=1996MiEng...9.1189W }}</ref>

Ilmenite ores can also be converted to liquid [[iron]] and a titanium-rich slag using a smelting process.<ref>{{citation| url = https://www.saimm.co.za/Journal/v108n01p035.pdf | title = Ilmenite smelting: the basics| first =  P.C. |last = Pistorius | journal = The Journal of the South African Institute of Mining and Metallurgy | volume = 108 | date = Jan 2008 }}</ref>

Ilmenite ore is used as a flux by steelmakers to line blast furnace hearth refractory.<ref name="RTFT Products">{{cite web|title=Rio Tinto, Fer et Titane - Products|url=http://www.rtft.com/ENC/index_ourproducts.asp|publisher=Rio Tinto Group|access-date=19 Aug 2012|archive-date=6 May 2015|archive-url=https://web.archive.org/web/20150506221657/http://www.rtft.com/ENC/index_ourproducts.asp|url-status=dead}}</ref>

Ilmenite can be used to produce [[ferrotitanium]] via an [[aluminothermic]] reduction.<ref name="FerroAlloy">{{cite book |title=Handbook of Ferroalloys: Theory and Technology |publisher=Elsevier |editor-last1=Gasik |editor-first1=Michael |year=2013 |location=London |pages=429 |isbn=978-0-08-097753-9}}</ref>

== Feedstock production ==
{| class="wikitable" style="float:right; clear:right; margin:0 0 .5em 1em;"
|+Various ilmenite feedstock grades.<ref>{{citation|last=Hayes|year=2011|first=Tony|title=Titanium Dioxide: A Shining Future Ahead|url=http://argex.ca/documents/Euro_Pacific_Canada_Titanium_Dioxide_August2011.pdf|publisher=Euro Pacific Canada|access-date=16 Aug 2012|page=5}}{{dead link|date=August 2018}}</ref>
|-
! Feedstock || {{Chem|Ti||O|2}} Content || Process
|-
!  || (%) || 
|-
| Ore || <55 || Sulfate 
|-
| Ore || >55 || Chloride
|-
| Ore || <50 || Smelting (slag)
|-
| Synthetic rutile  || 88–95 || Chloride
|-
| Chloride slag || 85–95 || Chloride
|-
| Sulfate slag || 80 || Sulfate
|}
{| class="wikitable" style="float:right; clear:right; margin:0 0 .5em 1em;"
|+Estimated contained {{Chem|Ti||O|2}}. <br> production{{sfn|Hayes|2011|p=5}}<ref>USGS 2012 Survey, p. 174</ref><br><small>(Metric tpa x 1,000,</small><br><small>ilmenite & rutile)</small>
|-
! Year || 2011 || 2012–13
|-
! Country || USGS || Projected
|-
| [[Australia]] || 1,300 || 247
|-
| [[South Africa]] || 1,161 || 190
|-
| [[Mozambique]]  || 516 || 250
|-
| [[Canada]]|| 700||
|-
| [[India]] || 574||
|-
| [[China]] || 500||
|-
| [[Vietnam]] || 490||
|-
| [[Ukraine]] || 357||
|-
| [[Senegal]] || - || 330
|-
| [[Norway]] || 300||
|-
| [[United States]] || 300||
|-
| [[Madagascar]] || 288||
|-
| [[Kenya]] || - || 246
|-
| [[Sri Lanka]] || 62 ||
|-
| [[Sierra Leone]] || 60||
|-
| [[Brazil]] || 48||
|-
| Other countries || 37||
|-
| Total world || ~6,700 || ~1,250
|}

Most ilmenite is recovered from heavy mineral sands ore deposits, where the mineral is concentrated as a [[placer deposit]] and weathering reduces its iron content, increasing the percentage of titanium. However, ilmenite can also be recovered from "hard rock" titanium ore sources, such as [[ultramafic to mafic layered intrusions]] or [[anorthosite]] [[massif]]s. The ilmenite in layered intrusions is sometimes abundant, but it contains considerable intergrowths of magnetite that reduce its ore grade. Ilmenite from anorthosite massifs often contain large amounts of calcium or magnesium that render it unsuitable for the chloride process.<ref>{{cite book |last1=Murphy |first1=Philip |last2=Frick |first2=Louise |title=Industrial minerals & rocks : commodities, markets, and uses. |date=2006 |publisher=Society for Mining, Metallurgy, and Exploration |location=Littleton, Colo. |isbn=9780873352338 |pages=990–991 |edition=7th |url=https://books.google.com/books?id=zNicdkuulE4C |access-date=23 February 2022 |chapter=Titanium |editor-first1=James M. |editor-last1=Barker |editor-first2=Jessica Elzea |editor-last2=Kogel |editor-first3=Nikhil C. |editor-last3=Trivedi |editor-first4=Stanley T. |editor-last4=Krukowski}}</ref>

The proven reserves of ilmenite and rutile ore are estimated at between 423 and 600 million tonnes titanium dioxide. The largest ilmenite deposits are in South Africa, India, the United States, Canada, Norway, Australia, Ukraine, Russia and Kazakhstan. Additional deposits are found in Bangladesh, Chile, Mexico and New Zealand.<ref>{{cite book |last1=Güther |first1=V. |last2=Sibum |first2=H. |last3=Roidl |first3=O. |last4=Habashi |first4=F. |last5=Wolf |first5=H |year= 2005 |chapter=Titanium, Titanium Alloys, and Titanium Compounds |title=Ullmann's Encyclopedia of Industrial Chemistry |publisher=Wiley InterScience |isbn=978-3-527-30673-2}}</ref>

Australia was the world's largest ilmenite ore producer in 2011, with about 1.3 million tonnes of production, followed by South Africa, Canada, Mozambique, India, China, Vietnam, Ukraine, Norway, Madagascar and United States.

The top four ilmenite and rutile feedstock producers in 2010 were [[Rio Tinto Group]], [[Iluka Resources]], Exxaro and [[Kenmare Resources]], which collectively accounted for more than 60% of world's supplies.{{sfn|Hayes|2011|p=3}}

The world's two largest [[Open cast mining|open cast]] ilmenite mines are:
* The [[Tellnes mine]] located in [[Sokndal]], [[Norway]], and run by Titania AS (owned by Kronos Worldwide Inc.) with 0.55 Mtpa capacity and 57 Mt contained {{Chem|Ti||O|2}} reserves.
* The Rio Tinto Group's Lac Tio mine located near [[Havre Saint-Pierre]], Quebec in [[Canada]] with a 3 Mtpa capacity and 52 Mt reserves.<ref name="Lac Tio Page">{{cite web|title=Lac Tio Mine|url=http://www.infomine.com/minesite/minesite.asp?site=lactio|publisher=InfoMine|access-date=16 Aug 2012}}</ref>

Major mineral sands based ilmenite mining operations include: 
* [[Richards Bay Minerals]] in [[South Africa]], majority-owned by the Rio Tinto Group.
* [[Kenmare Resources]]' Moma mine in [[Mozambique]].
* Iluka Resources' mining operations in Australia including Murray Basin, [[Eneabba, Western Australia|Eneabba]] and [[Capel, Western Australia|Capel]].
* The Kerala Minerals & Metals Ltd (KMML), [[Indian Rare Earths Limited|Indian Rare Earths]] (IRE), VV Mineral mines in India.
* TiZir Ltd.'s Grande Cote mine in [[Senegal]]<ref name="MDL Website">{{cite web|title=TiZir Limited|url=http://www.mineraldeposits.com.au/tizir/|publisher=Mineral Deposits Limited|access-date=16 Aug 2012|url-status=dead|archive-url=https://web.archive.org/web/20120818182108/http://www.mineraldeposits.com.au/tizir/|archive-date=2012-08-18}}</ref>
* [[QIT Madagascar Minerals]] mine, majority-owned by the Rio Tinto Group, which began production in 2009 and is expected to produce 0.75 Mtpa of ilmenite, potentially expanding to 2 Mtpa in future phases.

Attractive major potential ilmenite deposits include:
* The Karhujupukka magnetite-ilmenite deposit in Kolari, northern [[Finland]] with around 5 Mt reserves and ore containing about 6.2% titanium.
* The Balla Balla magnetite-iron-titanium-vanadium ore deposit in the [[Pilbara]] of [[Western Australia]], which contains 456 million tonnes of [[cumulate rocks|cumulate]] ore horizon grading 45% {{Chem|Fe}}, 13.7% {{Chem|Ti||O|2}} and 0.64% {{Chem|V|2|O|5}}, one of the richest magnetite-ilmenite ore bodies in Australia<ref>{{Cite web | url=http://www.australianminesatlas.gov.au/aimr/commodity/vanadium.html |title = Vanadium - AIMR 2011 - Australian Mines Atlas}}</ref>
* The Coburn, WIM 50, Douglas, [[Pooncarie]] mineral sands deposits in [[Australia]].
* The Magpie titano-magnetite (iron-titanium-vanadium-chrome) deposits in eastern [[Quebec]] of [[Canada]] with about 1 billion tonnes containing about 43% Fe, 12% TiO<sub>2</sub>, 0.4% V<sub>2</sub>O<sub>5</sub>, and 2.2% Cr<sub>2</sub>O<sub>3</sub>.
* The Longnose deposit in Northeast Minnesota is considered to be "the largest and richest ilmenite deposit in North America."<ref>{{Cite news|url=http://www.mprnews.org/story/2017/05/26/titanium-range-breakthrough-could-lead-to-new-kind-of-mining-in-ne-minn-|title=Titanium Range? Breakthrough could lead to new kind of mining in NE Minn.|last=Kraker|first=Dan|access-date=2017-05-31}}</ref>

[[File:Worldwide mining of the titanium-containing minerals ilmenite and rutile.png|thumb|Worldwide mining of the titanium-containing minerals ilmenite and rutile in thousand tonnes of TiO2 equivalent by country, in 2020.]]

In 2020, [[China]] has by far the highest titanium mining activity. About 35 percent of the world’s ilmenite is mined in China, representing 33 percent of total titanium mineral mining (including ilmenite and rutile). [[South Africa]] and [[Mozambique]] are also important contributors, representing 13 percent and 12 percent of worldwide ilmenite mining, respectively. [[Australia]] represents 6 percent of the total ilmenite mining and 31 percent of rutile mining. [[Sierra Leone]] and [[Ukraine]] are also big contributors to rutile mining.<ref name=":0" />

China is the biggest producer of titanium dioxide, followed by the United States and Germany. China is also the leader in the production of titanium metal, but Japan, the Russian Federation and Kazakhstan have emerged as important contributors to this field.

==Patenting activities==

[[File:Relevant patent families describing titanium dioxide production from ilmenite, 2002–2021.png|thumb|
Patent activity on titanium dioxide production from ilmenite has increased since 2012.]]
[[Patent]]ing activity related to titanium dioxide production from ilmenite is rapidly increasing.<ref name=":0" /> Between 2002 and 2022, there have been 459 [[Patent family|patent families]] that describe the production of titanium dioxide from ilmenite, and this number is growing rapidly. The majority of these patents describe pre-treatment processes, such as using smelting and magnetic separation to increase titanium concentration in low-grade ores, leading to titanium concentrates or slags. Other patents describe processes to obtain titanium dioxide, either by a direct hydrometallurgical process or through two industrially exploited processes, the sulfate process and the chloride process. Acid leaching might be used either as a pre-treatment or as part of a hydrometallurgical process to directly obtain titanium dioxide or synthetic rutile (>90 percent titanium dioxide, TiO2). The sulfate process represents 40 percent of the world’s titanium dioxide production and is protected in 23 percent of patent families. The chloride process is only mentioned in 8 percent of patent families, although it provides 60 percent of the worldwide industrial production of titanium dioxide.<ref name=":0" /><br>Key contributors to patents on the production of titanium dioxide are companies from China, Australia and the United States, reflecting the major contribution of these countries to industrial production. Chinese companies [[Pangang Group Vanadium Titanium & Resources|Pangang]] and [[Lomon Billions]] Groups are the main contributors and hold diversified [[patent portfolio]]s covering both pre-treatment and the processes leading to a final product.

In comparison, patenting activity related to titanium metal production from ilmenite remains stable.<ref name=":0" /> Between 2002 and 2022, there have been 92 patent families that describe the production of titanium metal from ilmenite, and this number has remained quite steady. These patents describe the production of titanium metal starting from mineral ores, such as ilmenite, and from titanium dioxide (TiO2) and titanium tetrachloride (TiCl4), a chemical obtained as an intermediate in the chloride process. The starting materials are purified if needed, and then converted to titanium metal by a chemical reduction process using a reducing agent. Processes mainly differ in regard to the reducing agent used to transform the starting material into titanium metal: magnesium is the most frequently cited reducing agent and the most exploited in industrial production.<br>Key players in the field are Japanese companies, in particular [[Toho Titanium Company Limited|Toho Titanium]] and [[Osaka Titanium Technologies]], both focusing on reduction using magnesium. Pangang also contributes to titanium metal production and holds patents describing reduction by molten salt electrolysis.<ref name=":0" />

==Lunar ilmenite==
Ilmenite has been found in [[Moon rock|lunar samples]], particularly in high-Ti [[lunar mare]] [[basalt]]s common from [[Apollo 11]] and [[Apollo 17]] sites, and on average, constitutes up to 5% of lunar meteorites.<ref>Korotev, Randy. 2005 "Lunar geochemistry as told by lunar meteorites." Geochemistry. Vol 65. Pages 297–346. https://doi.org/10.1016/j.chemer.2005.07.001</ref> Ilmenite has been targeted for [[In situ resource utilization|ISRU]] [[water]] and [[oxygen]] extraction due to a simplistic reduction reaction which occurs with CO and H<sub>2</sub> buffers.<ref>Schluter & Cowley. "Review of techniques for In-Situ oxygen extraction on the moon." Planetary and Space Science. Vol 181. https://doi.org/10.1016/j.pss.2019.104753</ref><ref>Perreault & Patience. "Ilmenite–CO reduction kinetics." Fuel. Vol 165. Pages 166-172. https://doi.org/10.1016/j.fuel.2015.10.066</ref><ref>Muscatello, Tony. 2017. "Oxygen Extraction from Minerals" Presentation, NASA KSC Applied Chem lab. https://ntrs.nasa.gov/api/citations/20170001458/downloads/20170001458.pdf</ref>

==Sources==
{{Free-content attribution
| title = Production of titanium and titanium dioxide from ilmenite and related applications
| publisher = WIPO
| documentURL = https://www.wipo.int/edocs/pubdocs/en/wipo-pub-1077-23-en-patent-landscape-report-ilmenite.pdf
| license = CC-BY
}}

== References ==
{{Reflist}}

{{Titanium minerals}}
{{Titanium compounds}}
{{Ores}}
{{iron compounds}}
{{Authority control}}

[[Category:Iron(II) minerals]]
[[Category:Titanium minerals]]
[[Category:Oxide minerals]]
[[Category:Ilmenite group]]
[[Category:Trigonal minerals]]
[[Category:Minerals in space group 148]]
[[Category:Magnetic minerals]]