what was wrong with the crusher?, page-7

Crushers dont usually extract anything. They merely crush hence the name. Usually the circuit would be some variation of: crushers to mill to cyclones, oversize back to mill, undersize to flotaton circuit, 'waste' to thickner overflow back to process water, underflow to tails dam.

Even though CDU have 2 mills the process is mostly the same. Flotation is where the copper con is ultimately upgraded and separated from the 'waste'.

Not trying to be pedantic, im an ex 'milly' :)