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Why is copper ore crushed and ground before further processing?
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copper processing
Molten copper being made into plates.
Copper ore is crushed and ground primarily to achieve the physical liberation of valuable copper minerals from waste rock, known as gangue. This process, known as comminution, is essential because minerals are typically found in an interlocked state within the ore.12
The specific requirements for this stage depend on the subsequent processing method:
- For sulfide ores: The ore must be ground to an optimal degree of liberation to facilitate selective flotation, where copper minerals are separated from waste by attaching to air bubbles in a slurry.1
- For oxide ores: The ore is crushed and ground to expose the mineral surfaces sufficiently to a leaching agent, though complete liberation is not always required.1
By reducing the ore to a powder or specific size, metallurgists ensure that the valuable copper can be efficiently recovered while the waste material is discarded.12