Editing Germanium (section)

== Production ==
About 118&nbsp;[[tonne]]s of germanium were produced in 2011 worldwide, mostly in China (80 t), Russia (5 t) and United States (3 t).<ref name="usgs" /> Germanium is recovered as a by-product from [[sphalerite]] zinc ores where it is concentrated in amounts as great as 0.3%,<ref>{{cite journal |doi=10.1016/0016-7037(85)90241-8 |title=Germanium geochemistry and mineralogy |date=1985 |last=Bernstein |first=L. |journal=Geochimica et Cosmochimica Acta |volume=49 |issue=11 |pages=2409–2422 |bibcode=1985GeCoA..49.2409B}}</ref> especially from low-temperature sediment-hosted, massive [[zinc|Zn]]–[[lead|Pb]]–[[copper|Cu]](–[[barium|Ba]]) deposits and carbonate-hosted Zn–Pb deposits.<ref>{{Cite journal |title=Gallium, germanium, indium and other minor and trace elements in sphalerite as a function of deposit type – A meta-analysis |last1=Frenzel |first1=Max |date=July 2016 |journal=Ore Geology Reviews |doi=10.1016/j.oregeorev.2015.12.017 |last2=Hirsch |first2=Tamino |last3=Gutzmer |first3=Jens |volume=76 |pages=52–78 |bibcode=2016OGRv...76...52F}}</ref> A recent study found that at least 10,000 t of extractable germanium is contained in known zinc reserves, particularly those hosted by [[Carbonate-hosted lead-zinc ore deposits|Mississippi-Valley type deposits]], while at least 112,000&nbsp;t will be found in coal reserves.<ref>{{multiref|{{Cite journal |title=On the geological availability of germanium |journal=Mineralium Deposita |date=2013-12-29 |issn=0026-4598 |pages=471–486 |volume=49 |issue=4 |doi=10.1007/s00126-013-0506-z |first1=Max |last1=Frenzel |first2=Marina P. |last2=Ketris |first3=Jens |last3=Gutzmer |bibcode=2014MinDe..49..471F |s2cid=129902592}}|{{Cite journal |title=Erratum to: On the geological availability of germanium |journal=Mineralium Deposita |date=2014-01-19 |issn=0026-4598 |page=487 |volume=49 |issue=4 |doi=10.1007/s00126-014-0509-4 |first1=Max |last1=Frenzel |first2=Marina P. |last2=Ketris |first3=Jens |last3=Gutzmer |bibcode=2014MinDe..49..487F |s2cid=140620827 |doi-access=free}}}}</ref> In 2007 35% of the demand was met by recycled germanium.<ref name="Holl" />

<div style="float: right; margin: 5px;">
{|class="wikitable" style="font-size:85%; text-align:right;"
!Year !! Cost<br />([[United States dollar|$]]/kg)<ref><!--two sources in one here?-->{{Cite book |title=USGS Minerals Information |url=http://minerals.usgs.gov/minerals/pubs/commodity/germanium/index.html#mcs |at=[http://minerals.usgs.gov/minerals/pubs/commodity/germanium/220303.pdf January 2003], [http://minerals.usgs.gov/minerals/pubs/commodity/germanium/germamcs04.pdf January 2004], [http://minerals.usgs.gov/minerals/pubs/commodity/germanium/germamcs05.pdf January 2005], [http://minerals.usgs.gov/minerals/pubs/commodity/germanium/germamcs06.pdf January 2006], [http://minerals.usgs.gov/minerals/pubs/commodity/germanium/germamcs07.pdf January 2007], [http://minerals.usgs.gov/minerals/pubs/commodity/germanium/mcs-2010-germa.pdf January 2010] |isbn=978-0-85934-039-7 |author=R.N. Soar |oclc=16437701 |date=1977 |publisher=Babani Press |access-date=2013-04-22 |archive-date=2013-05-07 |archive-url=https://web.archive.org/web/20130507125723/http://minerals.usgs.gov/minerals/pubs/commodity/germanium/index.html#mcs |url-status=live}}</ref>
|-
|1999 || 1,400
|-
|2000 || 1,250
|-
|2001 || 890
|-
|2002 || 620
|-
|2003 || 380
|-
|2004 || 600
|-
|2005 || 660
|-
|2006 || 880
|-
|2007 || 1,240
|-
|2008 || 1,490
|-
|2009 || 950
|-
|2010 || 940
|-
|2011 || 1,625
|-
|2012 || 1,680
|-
|2013 || 1,875
|-
|2014 || 1,900
|-
|2015 || 1,760
|-
|2016 || 950
|-
|2017 || 1,358
|-
|2018 || 1,300
|-
|2019 || 1,240
|-
|2020 || 1,000
|}
</div>
While it is produced mainly from [[sphalerite]], it is also found in [[silver]], [[lead]], and [[copper]] ores. Another source of germanium is [[fly ash]] of power plants fueled from coal deposits that contain germanium. Russia and China used this as a source for germanium.<ref name="Naumov">{{cite journal |first=A. V. |last=Naumov |title=World market of germanium and its prospects |journal=Russian Journal of Non-Ferrous Metals |volume=48 |issue=4 |date=2007 |doi=10.3103/S1067821207040049 |pages=265–272 |s2cid=137187498}}</ref> Russia's deposits are located in the far east of [[Sakhalin]] Island, and northeast of [[Vladivostok]]. The deposits in China are located mainly in the [[lignite]] mines near [[Lincang]], [[Yunnan]]; coal is also mined near [[Xilinhaote]], [[Inner Mongolia]].<ref name="Holl" />

The ore concentrates are mostly [[sulfide|sulfidic]]; they are converted to the [[oxide]]s by heating under air in a process known as [[Roasting (metallurgy)|roasting]]:

: GeS<sub>2</sub> + 3 O<sub>2</sub> → GeO<sub>2</sub> + 2 SO<sub>2</sub>

Some of the germanium is left in the dust produced, while the rest is converted to germanates, which are then leached (together with zinc) from the cinder by sulfuric acid. After neutralization, only the zinc stays in solution while germanium and other metals precipitate. After removing some of the zinc in the precipitate by the [[Waelz process]], the residing Waelz oxide is leached a second time. The [[germanium dioxide|dioxide]] is obtained as precipitate and converted with [[chlorine]] gas or hydrochloric acid to [[germanium tetrachloride]], which has a low boiling point and can be isolated by distillation:<ref name="Naumov" />

: GeO<sub>2</sub> + 4 HCl → GeCl<sub>4</sub> + 2 H<sub>2</sub>O
: GeO<sub>2</sub> + 2 Cl<sub>2</sub> → GeCl<sub>4</sub> + O<sub>2</sub>

Germanium tetrachloride is either hydrolyzed to the oxide (GeO<sub>2</sub>) or purified by fractional distillation and then hydrolyzed.<ref name="Naumov" /> The highly pure GeO<sub>2</sub> is now suitable for the production of germanium glass. It is reduced to the element by reacting it with hydrogen, producing germanium suitable for infrared optics and semiconductor production:

: GeO<sub>2</sub> + 2 H<sub>2</sub> → Ge + 2 H<sub>2</sub>O

The germanium for steel production and other industrial processes is normally reduced using carbon:<ref name="Moska">{{cite journal |journal=Minerals Engineering |date=2004 |pages=393–402 |doi=10.1016/j.mineng.2003.11.014 |title=Review of germanium processing worldwide |issue=3 |author=Moskalyk, R. R. |volume=17 |bibcode=2004MiEng..17..393M}}</ref>

: GeO<sub>2</sub> + C → Ge + CO<sub>2</sub>