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How does the copper content of an ore vary?
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copper processing
Molten copper being made into plates.
The copper content of an ore varies significantly depending on the type of deposit and the specific minerals present. Generally, the amount of copper in an ore can range from 0.4 percent to more than 12 percent.1
The variation is largely determined by the geological classification of the deposit:
- Porphyry copper deposits: These are the most significant sources of copper globally. Although they contain vast tonnages of rock, they are considered low-grade, typically averaging between 0.5 and 1.5 percent copper by weight.23
- Massive deposits: These generally contain a higher metal content than porphyry deposits but are more limited in their physical extent.1
- Native copper: In its unadulterated form, native copper can reach a purity of approximately 99.9 percent.1
The specific mineral composition also dictates the copper percentage. For example, sulfide ores like chalcocite can contain up to 79.9 percent copper, while chalcopyrite typically contains about 34.6 percent. During mineral processing, these ores are concentrated to reach a product containing between 20 and 30 percent copper before further extraction and refining processes are applied.14