Grasberg mine Wikipedia
It officially opened in 1973 (although the first ore shipment was in December 1972), and was expanded by Ertsberg East, which opened in 1981. Steep aerial tramways are used to transport equipment and people. Ore is dropped 600 metres (2,000 ft) from the mine, concentrated and mixed with water to form a 60:40 slurry. The slurry is then pumped through a 166 km pipeline through mountains, jungle and swamp to