Copper-Sulphur Separation
Many copper deposits contain significant pyrite that dilutes concentrate grade. Selective flotation separates copper sulphides from pyrite.
Lime Depression
Elevating pH to 10-12 with lime depresses pyrite while maintaining copper recovery. Most common and cost-effective method.
Cyanide Depression
Sodium cyanide selectively depresses pyrite at pH 7-9 when lime depression alone is insufficient.
Regrinding
Fine regrinding of rougher concentrate liberates copper minerals from pyrite before cleaner flotation.