Editing Lutetium (section)

==Occurrence and production==
[[Image:Monazit - Mosambik, O-Afrika.jpg|thumb|Monazite]]
Found with almost all other rare-earth metals but never by itself, lutetium is very difficult to separate from other elements. Its principal commercial source is as a by-product from the processing of the rare earth [[phosphate]] mineral [[monazite]] ({{chem|[[cerium|Ce]],[[lanthanum|La]],...)[[phosphorus|P]]|[[oxygen|O]]|4}}<!----please don't touch the formula---->, which has concentrations of only 0.0001% of the element,<ref name="aaaaaa" /> not much higher than the abundance of lutetium in the Earth crust of about 0.5&nbsp;mg/kg. No lutetium-dominant minerals are currently known.  <ref>{{cite web |url=https://www.mindat.org/ |title=Mindat.org |author=Hudson Institute of Mineralogy |date=1993–2018 |website=www.mindat.org |access-date=14 January 2018}}</ref> The main mining areas are China, United States, Brazil, India, Sri Lanka and Australia. The world production of lutetium (in the form of oxide) is about 10 tonnes per year.<ref name="Emsley240" /> Pure lutetium metal is very difficult to prepare. It is one of the rarest and most expensive of the rare earth metals with the price about US$10,000 per kilogram, or about one-fourth that of [[gold]].<ref>{{cite news| publisher = USGS| title =Rare-Earth Metals| author = Hedrick, James B. | access-date = 2009-06-06| url =http://minerals.usgs.gov/minerals/pubs/commodity/rare_earths/740798.pdf}}</ref><ref>{{cite book|title=Industrial Minerals and Rocks |chapter=Rare Earth Elements |author=Castor, Stephen B. |author2=Hedrick, James B. |publisher=Society for Mining, Metallurgy and Exploration |chapter-url=http://www.rareelementresources.com/i/pdf/RareEarths-CastorHedrickIMAR7.pdf |editor=Jessica Elzea Kogel, Nikhil C. Trivedi and James M. Barker |year=2006 |pages=769–792 |url-status=bot: unknown |archive-url=https://web.archive.org/web/20091007100717/http://www.rareelementresources.com/i/pdf/RareEarths-CastorHedrickIMAR7.pdf |archive-date=2009-10-07 }}</ref>

Crushed minerals are treated with hot concentrated [[sulfuric acid]] to produce water-soluble sulfates of rare earths. [[Thorium]] precipitates out of solution as hydroxide and is removed. After that the solution is treated with [[ammonium oxalate]] to convert rare earths into their insoluble oxalates. The oxalates are converted to oxides by annealing. The oxides are dissolved in [[nitric acid]] that excludes one of the main components, [[cerium]], whose oxide is insoluble in HNO<sub>3</sub>. Several rare earth metals, including lutetium, are separated as a double salt with [[ammonium nitrate]] by crystallization. Lutetium is separated by [[ion exchange]]. In this process, rare-earth ions are [[adsorption| adsorbed]] onto suitable ion-exchange resin by exchange with hydrogen, ammonium or cupric ions present in the resin. Lutetium salts are then selectively washed out by suitable complexing agent. Lutetium metal is then obtained by [[redox|reduction]] of anhydrous Lu[[chlorine|Cl]]<sub>3</sub> or Lu[[fluorine|F]]<sub>3</sub> by either an [[alkali metal]] or [[alkaline earth metal]].<ref name="patnaik">{{cite book|last =Patnaik|first =Pradyot|date = 2003|title =Handbook of Inorganic Chemical Compounds|publisher = McGraw-Hill|page = 510|isbn =978-0-07-049439-8|url= https://books.google.com/books?id=Xqj-TTzkvTEC&pg=PA243|access-date = 2009-06-06}}</ref>
 
: {{chem2|2 LuCl3 + 3 Ca → 2 Lu + 3 CaCl2}}

<sup>177</sup>Lu is produced by [[neutron activation]] of <sup>176</sup>Lu or by indirectly by neutron activation of <sup>176</sup>Yb followed by [[beta decay]]. The 6.693 day half life allows transport from the production reactor to the point of use without significant loss in activity.<ref name=PillaiKnapp/>