Editing Platinum (section)

== Production ==
{{further|List of countries by platinum production}}
[[File:Platinum Mining.jpg|thumb|An aerial photograph of a platinum mine in South Africa. South Africa accounts for ~80% of global platinum production and a majority of the world's known platinum deposits.]]
[[File:Platinum world production.svg|thumb|Time trend of platinum production<ref>Kelly, Thomas D. and Matos, Grecia R. (2013)[http://minerals.usgs.gov/ds/2005/140 Historical Statistics for Mineral and Material Commodities in the United States] {{webarchive|url=https://web.archive.org/web/20130604121254/http://minerals.usgs.gov/ds/2005/140/ |date=4 June 2013 }}, U.S. Geological Survey</ref>]]

Platinum, along with the rest of the [[Platinum group|platinum-group metals]], is obtained commercially as a by-product from [[nickel]] and [[copper]] mining and processing. During [[Copper extraction techniques#Electrorefining|electrorefining of copper]], noble metals such as silver, gold and the platinum-group metals as well as [[selenium]] and [[tellurium]] settle to the bottom of the cell as "anode mud", which forms the starting point for the extraction of the platinum-group metals.<ref name="usgs2010-yearbook">{{cite web |url=http://minerals.usgs.gov/minerals/pubs/commodity/platinum/myb1-2010-plati.pdf |author=Loferski, P. J. |title=2010 Minerals Yearbook; Platinum-group metals |publisher=USGS Mineral Resources Program |date=October 2011 |access-date=17 July 2012 |url-status=live |archive-url=https://web.archive.org/web/20120708061140/http://minerals.usgs.gov/minerals/pubs/commodity/platinum/myb1-2010-plati.pdf |archive-date=8 July 2012 |df=dmy-all }}</ref>

If pure platinum is found in [[placer deposits]] or other ores, it is isolated from them by various methods of subtracting impurities. Because platinum is significantly denser than many of its impurities, the lighter impurities can be removed by simply floating them away in a liquid. Platinum is [[paramagnetism|paramagnetic]], whereas nickel and iron are both [[Ferromagnetism|ferromagnetic]]. These two impurities are thus removed by running an electromagnet over the mixture. Because platinum has a higher melting point than most other substances, many impurities can be burned or melted away without melting the platinum. Finally, platinum is resistant to hydrochloric and sulfuric acids, whereas other substances are readily attacked by them. Metal impurities can be removed by stirring the mixture in either of the two acids and recovering the remaining platinum.<ref name="heiserman">{{cite book|title = Exploring Chemical Elements and their Compounds|last = Heiserman|first = David L.|pages = [https://archive.org/details/exploringchemica01heis/page/272 272–4]|publisher = TAB Books|isbn = 978-0-8306-3018-9|date = 1992|url = https://archive.org/details/exploringchemica01heis/page/272}}</ref>

One suitable method for purification for the raw platinum, which contains platinum, gold, and the other platinum-group metals, is to process it with ''aqua regia'', in which palladium, gold and platinum are dissolved, whereas osmium, iridium, ruthenium and rhodium stay unreacted. The gold is precipitated by the addition of [[iron(II) chloride]] and after filtering off the gold, the platinum is precipitated as [[Ammonium hexachloroplatinate|ammonium chloroplatinate]] by the addition of [[ammonium chloride]]. Ammonium chloroplatinate can be converted to platinum by heating.<ref>{{cite journal|first1 = L. B.|last1 = Hunt|last2 = Lever|first2 = F. M.|journal = Platinum Metals Review|volume = 13|issue = 4|date = 1969|pages = 126–138|title = Platinum Metals: A Survey of Productive Resources to industrial Uses| doi=10.1595/003214069X134126138 |url = http://www.platinummetalsreview.com/pdf/pmr-v13-i4-126-138.pdf|url-status = live|archive-url = https://web.archive.org/web/20081029205825/http://www.platinummetalsreview.com/pdf/pmr-v13-i4-126-138.pdf|archive-date = 29 October 2008|df = dmy-all}}</ref> Unprecipitated hexachloroplatinate(IV) may be reduced with elemental [[zinc]], and a similar method is suitable for small scale recovery of platinum from laboratory residues.<ref>{{Cite book | series = Inorg. Synth. | author1 = Kauffman, George B. | author2 = Teter, Larry A. | author3 = Rhoda, Richard N. | title = Inorganic Syntheses | chapter = Recovery of Platinum from Laboratory Residues | name-list-style = amp| doi = 10.1002/9780470132388.ch61 | date = 1963 | isbn = 978-0-470-13238-8 | volume = 7 | pages = 232–6}}</ref> Mining and refining platinum has environmental impacts.<ref>{{cite web |url=http://www.thejournalist.org.za/wp-content/uploads/2014/09/Environmental-health-impacts-of-platinum-mining1.pdf |title=Health and environmental impacts of platinum mining: Report from South Africa |date=March 2014 |first=E. |last=Cairncross |access-date=2016-10-04 |url-status=live |archive-url=https://web.archive.org/web/20161005130944/http://www.thejournalist.org.za/wp-content/uploads/2014/09/Environmental-health-impacts-of-platinum-mining1.pdf |archive-date=5 October 2016 |df=dmy-all }}</ref>