- Rocks are mixtures of minerals.
- A mineral can be made up of uncombined elements or compounds.
- Although copper can be found in nature as the uncombined element, it is often found in nature as compounds.
Common Copper Minerals Classification Mineral name formula appearance % copper element native copper Cu reddish, metallic 100% oxide cuprite Cu2O red, earthy 89% tenorite CuO grey black 80% sulfide chalcocite Cu2S dark grey, metallic 80% covellite CuS indigo blue 66% bornite Cu5FeS4 golden brown, earthy 63% chalcopyrite CuFeS2 golden yellow, metallic 35% carbonate malachite Cu2CO3(OH)2 bright green, earthy 58% azurite Cu3(CO3)2(OH)2 blue, glassy 55%
- A copper ore is a mixture of copper minerals and other materials in the rock called gangue, from which it is economically viable to extract the metal.
A typical copper ore contains between 0.5% and 2.0% copper.
- A high grade ore produces a high yield of metal.
A low grade order produces a low yield of metal.
- Copper can be extracted from sulfide ores (usually higher grade ores) by direct smelting.
The earliest evidence of copper smelting occurs in Serbian artefacts dating from around 5000 BC.
Copper can be extracted from oxide ores using electrolysis (electrowinning) for low grade ores, or by the carbon reduction method of smelting for higher grade ores.
- The process of extracting copper from higher grade sulfide ores involves:
|Physical Processes||Chemical Processes|