The most common method of mining porphyry copper, and the least expensive where a large orebody is situated close to the surface.
A surficial mining method for extraction of ore that lies near the earthâ€™s surface. The ore must first be exposed by the removal of barren overburden and waste rock.
Open-pit mining is the most common mining method because of the low costs and high production volumes that it affords. However it requires an ore-body to be near the surface.