Bougainville Copper Ltd is an Australian copper, gold, and silver mining company that operates the Panguna open cut mine on the island of Bougainville in Papua New Guinea (PNG). It was one of the world's largest open-pit mines. The Panguna mine dominated the economy of the island during the 1970s and 1980s. It also was highly significant to the overall PNG economy: In the 1970s and the 1980s the company's tax and dividend payments added up to approx.