Editing Ruthenium (section)

== Production ==
Roughly 30&nbsp;tonnes of ruthenium are mined each year,<ref name=usgs/> and world reserves are estimated at 5,000&nbsp;tonnes.<ref name=Emsley>{{cite book |last=Emsley |first=J. |year=2003 |title=Nature's Building Blocks: An A-Z guide to the elements |publisher=Oxford University Press |isbn=978-0-19-850340-8 |location=Oxford, UK |pages=[https://archive.org/details/naturesbuildingb0000emsl/page/368 368]–370 |chapter=Ruthenium |chapter-url=https://archive.org/details/naturesbuildingb0000emsl/page/368 |via=archive.org }}</ref> The composition of the mined [[platinum group metal]] (PGM) mixtures varies widely, depending on the geochemical formation. For example, the PGMs mined in South Africa contain on average 11% ruthenium while the PGMs mined in the former USSR contain only 2% (1992).<ref>{{cite book |editor1 = Hartman, H. L. |editor2 = Britton, S. G. |year = 1992 |title = SME mining engineering handbook |publisher = Society for Mining, Metallurgy, and Exploration |location = Littleton, CO |page =69 |isbn = 978-0-87335-100-3 |url = https://books.google.com/books?id=Wm6QMRaX9C4C&pg=PA69 |via = Google }}</ref><ref>{{cite journal |last1=Harris |first1=Donald C. |last2=Cabri |first2=Louis J. |date=August 1973 |title=The nomenclature of the natural alloys of osmium, iridium and ruthenium based on new compositional data of alloys from world-wide occurrences |journal=The Canadian Mineralogist |volume=12 |issue=2 |pages=104–112 |id={{NAID|20000798606}} |url=https://pubs.geoscienceworld.org/canmin/article-abstract/12/2/104/10913/The-nomenclature-of-the-natural-alloys-of-osmium }}</ref> Ruthenium, osmium, and iridium are considered the minor platinum group metals.{{sfnp|Greenwood|Earnshaw|1997|p=1074}}

Ruthenium, like the other platinum group metals, is obtained commercially as a by-product from processing of [[nickel]], [[copper]], and platinum metal ore. During [[Copper extraction techniques#Electrorefining|electrorefining of copper]] and nickel, noble metals such as silver, gold, and the platinum group metals precipitate as ''anode mud'', the [[feedstock]] for the extraction.<ref name=USGS-YB-2006/><ref name=USGS-CS-2008/> The metals are converted to ionized solutes by any of several methods, depending on the composition of the feedstock. One representative method is fusion with [[sodium peroxide]] followed by dissolution in [[aqua regia]], and solution in a mixture of [[chlorine]] with [[hydrochloric acid]].<ref name=ullmann-pt>
{{cite book
 |last1=Renner       |first1=Hermann      |last2=Schlamp  |first2=Günther
 |last3=Kleinwächter |first3=Ingo         |last4=Drost    |first4=Ernst
 |last5=Lüschow      |first5=Hans Martin  |last6=Tews     |first6=Peter
 |last7=Panster      |first7=Peter        |last8=Diehl    |first8=Manfred
 |last9=Lang         |first9=Jutta        |last10=Kreuzer |first10=Thomas
 |last11=Knödler     |first11=Alfons      |last12=Starz   |first12=Karl Anton
 |last13=Dermann     |first13=Klaus       |last14=Rothaut |first14=Josef
 |last15=Drieselmann |first15=Ralf        |last16=Peter   |first16=Catrin
 |last17=Schiele     |first17=Rainer
 |display-authors=6
 |year=2001
 |chapter=Platinum group metals and compounds
 |title=Ullmann's Encyclopedia of Industrial Chemistry
 |isbn=978-3-527-30673-2 |doi=10.1002/14356007.a21_075
}}
</ref><ref name=kirk-pt>{{cite book |first1 = R.J. |last1 = Seymour |last2 = O'Farrelly |first2 = J.I. |year=2001 |chapter=Platinum-group metals |title=Kirk Othmer Encyclopedia of Chemical Technology |publisher=Wiley |isbn = 978-0471238966 |doi=10.1002/0471238961.1612012019052513.a01.pub2 }}</ref> [[Osmium]] (Os), ruthenium (Ru), [[rhodium]] (Rh), and [[iridium]] (Ir) are insoluble in aqua regia and readily precipitate, leaving the other metals in solution. Rhodium is separated from the residue by treatment with molten sodium bisulfate. The insoluble residue, containing Ru, Os, and Ir is treated with sodium oxide, in which Ir is insoluble, producing dissolved Ru and Os salts. After oxidation to the volatile oxides, {{chem|RuO|4}} is separated from {{chem|OsO|4}} by precipitation of (NH<sub>4</sub>)<sub>3</sub>RuCl<sub>6</sub> with ammonium chloride or by distillation or extraction with organic solvents of the volatile osmium tetroxide.<ref>{{cite journal |first = Raleigh |last = Gilchrist |year = 1943 |title = The platinum metals |journal = Chemical Reviews |volume = 32 |issue = 3 |pages = 277–372 |doi = 10.1021/cr60103a002 | s2cid=96640406 }}</ref> [[Hydrogen]] is used to reduce [[ammonium]] ruthenium chloride, yielding a powder.{{sfnp|Haynes|2016|p=4.31}}<ref name=cotton>{{cite book |last = Cotton |first = Simon |year = 1997 |title = Chemistry of Precious Metals |pages = 1–20|publisher = Springer-Verlag |place=New York, NY |isbn = 978-0-7514-0413-5 |url = https://books.google.com/books?id=6VKAs6iLmwcC&pg=PA2 }}</ref> The product is reduced using hydrogen, yielding the metal as a powder or [[sponge metal]] that can be treated with [[powder metallurgy]] techniques or [[argon]]-[[arc welding]].{{sfnp|Haynes|2016|p=4.31}}<ref name="Hunt 1969 126–138">{{cite journal |first1=L.B. |last1=Hunt |last2=Lever |first2=F.M. |year=1969 |journal=Platinum Metals Review |volume=13 |issue=4 |pages=126–138 |title=Platinum metals: A survey of productive resources to industrial uses |doi=10.1595/003214069X134126138 |s2cid=267561907 |url=http://www.platinummetalsreview.com/pdf/pmr-v13-i4-126-138.pdf |url-status=dead |access-date=2 June 2009 |archive-url=https://web.archive.org/web/20081029205825/http://www.platinummetalsreview.com/pdf/pmr-v13-i4-126-138.pdf |archive-date=29 October 2008 }}</ref>

Ruthenium is contained in [[spent nuclear fuel]], both as a direct [[fission product]] and as a product of [[neutron absorption]] by [[long-lived fission product]] {{Chem|99|Tc| link= Technetium-99}}. After allowing the unstable [[isotopes of ruthenium]] to decay, chemical extraction could yield ruthenium for use in all applications of ruthenium.<ref>{{cite journal |last1=Swain |first1=Pravati |last2=Mallika |first2=C. |last3=Srinivasan |first3=R. |last4=Mudali |first4=U. Kamachi |last5=Natarajan |first5=R. |date=November 2013 |title=Separation and recovery of ruthenium: A review |journal=Journal of Radioanalytical and Nuclear Chemistry |volume=298 |issue=2 |pages=781–796 |doi=10.1007/s10967-013-2536-5 |bibcode=2013JRNC..298..781S |s2cid=95804621 }}</ref><ref>{{cite journal |last1=Johal |first1=Sukhraaj Kaur |last2=Boxall |first2=Colin |last3=Gregson |first3=Colin |last4=Steele |first4=Carl |title=Ruthenium Volatilisation from Reprocessed Spent Nuclear Fuel – Studying the Baseline Thermodynamics of Ru(III) |journal=ECS Transactions |date=24 July 2015 |volume=66 |issue=21 |pages=31–42 |doi=10.1149/06621.0031ecst |bibcode=2015ECSTr..66u..31J |url=https://eprints.lancs.ac.uk/id/eprint/78523/2/SJohal_CBoxall_ECSTrans_Paper_16_July_2015_Final_v2.pdf }}</ref>

Ruthenium can also be produced by deliberate [[nuclear transmutation]] from {{chem|99|Tc}}. Given its relatively long half life, high [[fission product yield]] and high chemical mobility in the environment, {{chem|99|Tc}} is among the most often proposed non-[[actinide]]s for commercial scale nuclear transmutation. {{Chem|99|Tc}} has a relatively large [[neutron cross section]], and because technetium has no stable isotopes, there would not be a problem of [[neutron activation]] of stable isotopes. Significant amounts of {{chem|99|Tc}} are produced in nuclear fission. They are also produced as a byproduct of the use of {{chem|99m|Tc| link= Technetium-99m}} in [[nuclear medicine]], because this isomer decays to {{chem|99|Tc}}. Exposing the {{chem|99|Tc}} target to strong enough [[neutron radiation]] will eventually yield appreciable quantities of ruthenium, which can be chemically separated while consuming {{chem|99|Tc}}.<ref>{{cite journal |last1=Konings |first1=R.J.M. |last2=Conrad |first2=R. |date=September 1999 |title=Transmutation of technetium – results of the EFTTRA-T2 experiment |journal=Journal of Nuclear Materials |volume=274 |issue=3 |pages=336–340 |doi=10.1016/S0022-3115(99)00107-5 |bibcode=1999JNuM..274..336K }}</ref><ref>{{cite journal |last1=Peretroukhine |first1=Vladimir |last2=Radchenko |first2=Viacheslav |last3=Kozar' |first3=Andrei |last4=Tarasov |first4=Valeriy |last5=Toporov |first5=Iury |last6=Rotmanov |first6=Konstantin |last7=Lebedeva |first7=Lidia |last8=Rovny |first8=Sergey |last9=Ershov |first9=Victor |display-authors=6 |date=December 2004 |title=Technetium transmutation and production of artificial stable ruthenium |journal=Comptes Rendus Chimie |volume=7 |issue=12 |pages=1215–1218 |doi=10.1016/j.crci.2004.05.002 |url=https://comptes-rendus.academie-sciences.fr/chimie/articles/10.1016/j.crci.2004.05.002/ }}</ref>