Malachite

===Ore uses===
[[File:Natural_copper_nugget.jpg|thumb|Copper nugget example]]
Simple methods of [[copper ore]] extraction from malachite involved thermodynamic processes such as [[smelting]].<ref name="Johnson-2004">{{Cite journal|last1=Johnson|first1=Cris E.|last2=Yee|first2=Gordon T.|last3=Eddleton|first3=Jeannine E.|date=2004-12-01|title=Copper Metal from Malachite circa 4000 B.C.E.|url=https://doi.org/10.1021/ed081p1777|journal=Journal of Chemical Education|volume=81|issue=12|pages=1777|doi=10.1021/ed081p1777|bibcode=2004JChEd..81.1777J|issn=0021-9584}}</ref> This reaction involves the addition of heat and a carbon, causing the carbonate to decompose leaving [[Copper(II) oxide|copper oxide]] and an additional carbon source such as coal converts the copper oxide into copper metal.<ref name="Johnson-2004"/><ref name="Day-2019">{{Citation|last1=Day|first1=Jo|title=Reconstructing a Bronze Age Kiln from Priniatikos Pyrgos, Crete|date=2019-09-30|url=http://dx.doi.org/10.2307/j.ctvpmw4g8.11|work=Experimental Archaeology: Making, Understanding, Story-telling|pages=63–72|publisher=Archaeopress Publishing Ltd|isbn=978-1-78969-320-1|access-date=2021-02-25|last2=Kobik|first2=Maggie|doi=10.2307/j.ctvpmw4g8.11|s2cid=210629355}}</ref>

The basic word equation for this reaction is:

Copper carbonate + heat → carbon dioxide + copper oxide (color changes from green to black).<ref name="Johnson-2004"/><ref name="Day-2019"/>

Copper oxide + carbon → carbon dioxide + copper (color change from black to copper colored).<ref name="Johnson-2004"/><ref name="Day-2019"/>

Malachite is a low grade copper ore, however, due to increase demand for metals, more economic processing such as [[Hydrometallurgy|hydrometallurgical]] methods (using aqueous solutions such as [[sulfuric acid]]) are being used as malachite is readily soluble in dilute acids.<ref>{{Cite journal|last1=Ata|first1=O. N.|last2=Yalap|first2=H.|date=2007-06-01|title=Optimization of Copper Leaching from Ore Containing Malachite|url=https://doi.org/10.1179/cmq.2007.46.2.107|journal=Canadian Metallurgical Quarterly|volume=46|issue=2|pages=107–114|doi=10.1179/cmq.2007.46.2.107|bibcode=2007CaMQ...46..107A |s2cid=98163205|issn=0008-4433}}</ref><ref>{{Cite web|title=Malachite|url=https://www.mindat.org/min-2550.html|access-date=2021-03-12|website=www.mindat.org}}</ref> [[Sulfuric acid]] is the most common leaching agent for copper oxide ores like malachite and eliminates the need for smelting processes.<ref name="Shabani-2012">{{Cite journal|last1=Shabani|first1=M. A.|last2=Irannajad|first2=M.|last3=Azadmehr|first3=A. R.|date=2012-09-01|title=Investigation on leaching of malachite by citric acid|url=https://doi.org/10.1007/s12613-012-0628-9|journal=International Journal of Minerals, Metallurgy, and Materials|language=en|volume=19|issue=9|pages=782–786|doi=10.1007/s12613-012-0628-9|bibcode=2012IJMMM..19..782S|s2cid=96128268|issn=1869-103X}}</ref>

The chemical equation for sulfuric acid leaching of copper ore from malachite is as follows:<ref name="Shabani-2012"/>

{{NumBlk|:
|{{overset|malachite|{{chem2|Cu2(OH)2CO3}}}} + {{overset|sulfuric acid|{{chem2|2H2SO4}}}} → {{overset|copper sulfate|{{chem2|2CuSO4}}}} + {{overset|carbon dioxide|{{chem2|CO2}}}} + {{overset|water|{{chem2|3H2O}}}}
|{{EquationRef|Reaction 1}}}}