This metal appears as one of the most widely used, thus there's more interest about the methods to recycle it. Without establishing a plan, the result would be inadequate, leading to lack, higher prices and other related issues.
Like aluminum, copper is fully recyclable so this property creates an extensive industry. Currently, copper also stays as one of the most recycled metals.
The industry knows several methods to increase purity avoiding alloys and ensuring almost pure copper, finally the third best conductor after graphene (still being actualized in some places as it's somewhat new) and silver. As always, not only the purity, but also the area of the conductor.
As cooper has been used for thousands of years, there's a high probability of using copper that was mined in ancient times, then it would be the same that stays for instance in the circuit board of any new electronic device! Mesopotamia, Ancient Egypt, Aztecs, who knows… although with machines seems easier.