Editing Curium (section)

===Metal preparation===
[[File:Elutionskurven Tb Gd Eu und Bk Cm Am.png|thumb|[[Chromatography|Chromatographic]] [[elution]] curves revealing the similarity between Tb, Gd, Eu lanthanides and corresponding Bk, Cm, Am actinides]]
Most synthesis routines yield a mix of actinide isotopes as [[oxide]]s, from which a given isotope of curium needs to be separated. An example procedure could be to dissolve spent reactor fuel (e.g. [[MOX fuel]]) in [[nitric acid]], and remove the bulk of the uranium and plutonium using a [[PUREX]] ('''P'''lutonium – '''UR'''anium '''EX'''traction) type extraction with [[tributyl phosphate]] in a hydrocarbon. The lanthanides and the 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. A curium compound is then selectively extracted using multi-step [[chromatography|chromatographic]] and centrifugation techniques with an appropriate reagent.<ref>Penneman, pp. 34–48</ref> [[BTBP|''Bis''-triazinyl bipyridine]] complex has been recently proposed as such reagent which is highly selective to 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|issue = 2|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|title-link = centrifugal extractor|s2cid = 94720457}}</ref> Separation of curium from the very chemically similar americium can also be done by treating a slurry of their hydroxides in aqueous [[sodium bicarbonate]] with [[ozone]] at elevated temperature. Both americium and curium are present in solutions mostly in the +3 valence state; americium oxidizes to soluble Am(IV) complexes, but curium stays unchanged and so can be isolated by repeated centrifugation.<ref>Penneman, p. 25</ref>

Metallic curium is obtained by [[Redox|reduction]] of its compounds. Initially, curium(III) fluoride was used for this purpose. The reaction was done in an environment free of water and oxygen, in an apparatus made of [[tantalum]] and [[tungsten]], using elemental [[barium]] or [[lithium]] as reducing agents.<ref name="Morrs" /><ref name = "CM_METALL" /><ref name="cunning">{{cite journal|last1=Cunningham|first1=B. B.|last2=Wallmann|first2=J. C.|title=Crystal structure and melting point of curium metal|journal=Journal of Inorganic and Nuclear Chemistry|volume=26|issue=2|page=271|date=1964|doi=10.1016/0022-1902(64)80069-5|osti=4667421}}</ref><ref>{{cite journal|last1=Stevenson|first1=J.|last2=Peterson|first2=J.|title=Preparation and structural studies of elemental curium-248 and the nitrides of curium-248 and berkelium-249|journal=Journal of the Less Common Metals|volume=66|issue=2|page=201|date=1979|doi=10.1016/0022-5088(79)90229-7}}</ref><ref>''Gmelin Handbook of Inorganic Chemistry'', System No. 71, Volume 7 a, transuranics, Part B 1, pp. 67–68.</ref>
:<math>\mathrm{CmF_3\ +\ 3\ Li\ \longrightarrow \ Cm\ +\ 3\ LiF}</math>

Another possibility is reduction of curium(IV) oxide using a magnesium-zinc alloy in a melt of [[magnesium chloride]] and [[magnesium fluoride]].<ref>{{cite journal|last1=Eubanks|first1=I.|title=Preparation of curium metal|journal=Inorganic and Nuclear Chemistry Letters|volume=5|issue=3|page=187|date=1969|doi=10.1016/0020-1650(69)80221-7|last2=Thompson|first2=M. C.}}</ref>