Editing Cadmium (section)

==Production==
Cadmium is a common impurity in [[zinc]] ores, and it is most often isolated during the [[Zinc smelting|production of zinc]]. Some zinc ores concentrates from [[zinc sulfate]] ores contain up to 1.4% of cadmium.<ref name="Cd-Trend">
{{cite book
 |last=Golberg |first=D. C.
 |date=1969
 |title=Trends in Usage of Cadmium: Report
 |url=https://books.google.com/books?id=okArAAAAYAAJ
 |pages=1–3
 |publisher=[[United States National Research Council|US NRC]]/[[National Academy of Sciences|NAS]]/[[National Academy of Engineering|NAE]]
|display-authors=etal}}</ref> In the 1970s, the output of cadmium was {{convert|6.5|lb|order=flip}} per ton of zinc.<ref name="Cd-Trend" /> Zinc [[sulfide]] ores are roasted in the presence of [[oxygen]], converting the zinc sulfide to the [[oxide]]. Zinc metal is produced either by [[smelting]] the oxide with [[carbon]] or by [[electrolysis]] in [[sulfuric acid]]. Cadmium is isolated from the zinc metal by [[vacuum distillation]] if the zinc is smelted, or cadmium sulfate is [[precipitate]]d from the electrolysis solution.<ref name="lifecycle" /><ref>
{{cite book
 |last1=Scoullos |first1=M. J.
 |date=2001
 |title=Mercury, Cadmium, Lead: Handbook for Sustainable Heavy Metals Policy and Regulation
 |url=https://books.google.com/books?id=9yzN-QGag_8C&pg=PA104
 |pages=104–116
 |publisher=[[Springer (publisher)|Springer]]
 |isbn=978-1-4020-0224-3
}}</ref>

The [[British Geological Survey]] reports that in 2001, China was the top producer of cadmium with almost one-sixth of the world's production, closely followed by South Korea and Japan.<ref>{{cite book|last1=Hetherington|first1=L. E.|title=World Mineral Production 2002–06|date=2008|publisher=[[British Geological Survey]]|page=15|chapter=Production of Cadmium|display-authors=etal|access-date=15 April 2012|chapter-url=http://nora.nerc.ac.uk/3260/2/FINAL_WMP_2002_2006_COMPLETE_WEB.pdf|archive-url=https://web.archive.org/web/20121108102639/http://nora.nerc.ac.uk/3260/2/FINAL_WMP_2002_2006_COMPLETE_WEB.pdf|archive-date=2012-11-08|url-status=dead}}</ref>

<gallery widths="200" heights="160">
File:Cadmium - world production trend.svg|History of the world production of cadmium
File:2022cadmium.png|Cadmium production in 2010
</gallery>