Editing Americium (section)

=== Metal generation ===
Most synthesis routines yield a mixture of different actinide isotopes in oxide forms, from which isotopes of americium can be separated. In a typical procedure, the spent reactor fuel (e.g. [[MOX fuel]]) is dissolved in [[nitric acid]], and the bulk of uranium and plutonium is removed using a [[PUREX]]-type extraction ('''P'''lutonium–'''UR'''anium '''EX'''traction) with [[tributyl phosphate]] in a [[hydrocarbon]]. The lanthanides and remaining actinides are then separated from the aqueous residue ([[raffinate]]) by a [[diamide]]-based extraction, to give, after stripping, a mixture of trivalent actinides and lanthanides. Americium compounds are then selectively extracted using multi-step [[chromatographic]] and centrifugation techniques<ref>Penneman, pp. 34–48</ref> with an appropriate reagent. A large amount of work has been done on the [[solvent extraction]] of americium. For example, a 2003 [[EU]]-funded project codenamed "EUROPART" studied [[triazine]]s and other compounds as potential extraction agents.<ref>{{cite journal|journal = [[Dalton Trans.]]|date = 2003|pages = 1675–1685|doi = 10.1039/b301178j|title = The coordination chemistry of 1,2,4-triazinyl bipyridines with lanthanide(III) elements – implications for the partitioning of americium(III)|author = Hudson, M. J.|issue = 9|display-authors=etal}}</ref><ref>{{cite web|author = Geist, A.|title = Actinide(III)/Lanthanide(III) Partitioning Using n-Pr-BTP as Extractant: Extraction Kinetics and Extraction Test in a Hollow Fiber Module|work = 6th Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation|publisher = [[OECD Nuclear Energy Agency]]|date = 11–13 December 2000|url = https://www.oecd-nea.org/pt/docs/iem/madrid00/Proceedings/Paper14.pdf|display-authors = etal|access-date = 26 May 2014|archive-date = 24 September 2015|archive-url = https://web.archive.org/web/20150924055355/http://www.oecd-nea.org/pt/docs/iem/madrid00/Proceedings/Paper14.pdf|url-status = dead}}</ref><ref>{{cite web|url = http://www-atalante2004.cea.fr/home/liblocal/docs/atalante2000/P3-26.pdf|title = Sanex-BTP Process Development Studies|work = Atalante 2000: Scientific Research on the Back-end of the Fuel Cycle for the 21st Century|publisher = Commissariat à l'énergie atomique|date = 24–26 October 2000|author = Hill, C.|author2 = Guillaneux, D.|author3 = Hérès, X.|author4 = Boubals, N.|author5 = Ramain, L.|name-list-style = amp|url-status = dead|archive-url = https://web.archive.org/web/20121115151847/http://www-atalante2004.cea.fr/home/liblocal/docs/atalante2000/P3-26.pdf|archive-date = 15 November 2012}}</ref><ref>{{cite web|title = Effective Actinide(III)-Lanthanide(III) Separation in Miniature Hollow Fibre Modules|author = Geist, A.|url = http://www.nea.fr/html/pt/docs/iem/jeju02/session2/SessionII-15.pdf|work = 7th Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation|date = 14–16 October 2002|publisher = OECD Nuclear Energy Agency|display-authors = etal|access-date = 17 March 2007|archive-date = 29 September 2009|archive-url = https://web.archive.org/web/20090929023456/http://www.nea.fr/html/pt/docs/iem/jeju02/session2/SessionII-15.pdf|url-status = dead}}</ref><ref>{{cite web|title = Separation Studies of ''f''-Elements|author = Ensor, D.D.|publisher = [[Tennessee Tech University]]|url = http://www.tntech.edu/WRC/pdfs/Projects04_05/Ens_Elem.pdf|url-status = dead|archive-url = https://web.archive.org/web/20060922113030/http://www.tntech.edu/wrc/pdfs/Projects04_05/Ens_Elem.pdf|archive-date = 22 September 2006}}</ref> A [[BTBP|''bis''-triazinyl bipyridine]] complex was proposed in 2009 as such a reagent is highly selective to americium (and curium).<ref>{{cite journal|author = Magnusson D|author2 = Christiansen B|author3 = Foreman MRS|author4 = Geist A|author5 = Glatz JP|author6 = Malmbeck R|author7 = Modolo G|author8 = Serrano-Purroy D|author9 = Sorel C|name-list-style = amp|journal = Solvent Extraction and Ion Exchange|date = 2009|volume = 27|page = 97|doi = 10.1080/07366290802672204|title = Demonstration of a SANEX Process in Centrifugal Contactors using the CyMe4-BTBP Molecule on a Genuine Fuel Solution|issue = 2|title-link = centrifugal extractor|s2cid = 94720457}}</ref> Separation of americium from the highly similar curium can be achieved by treating a slurry of their hydroxides in aqueous [[sodium bicarbonate]] with [[ozone]], at elevated temperatures. Both Am and Cm are mostly present in solutions in the +3 valence state; whereas curium remains unchanged, americium oxidizes to soluble Am(IV) complexes which can be washed away.<ref>Penneman, p. 25</ref>

Metallic americium is obtained by [[Redox|reduction]] from its compounds. [[Americium(III) fluoride]] was first used for this purpose. The reaction was conducted using elemental [[barium]] as reducing agent in a water- and oxygen-free environment inside an apparatus made of [[tantalum]] and [[tungsten]].<ref name="AM_METALL1" /><ref name = "Gmelin">''Gmelin Handbook of Inorganic Chemistry'', System No. 71, transuranics, Part B 1, pp. 57–67.</ref><ref name="p3">Penneman, p. 3</ref>

: <math>\mathrm{2\ AmF_3\ +\ 3\ Ba\ \longrightarrow \ 2\ Am\ +\ 3\ BaF_2}</math>

An alternative is the reduction of [[americium dioxide]] by metallic [[lanthanum]] or [[thorium]]:<ref name="p3" /><ref name="AM_METALL2" />

: <math>\mathrm{3\ AmO_2\ +\ 4\ La\ \longrightarrow \ 3\ Am\ +\ 2\ La_2O_3}</math>