The Batu Hijau mine is an open pit copper-gold mine operated by PT. Amman Mineral Nusa Tenggara. The mine is the second largest copper-gold mine in Indonesia behind the Grasberg mine of PT. Freeport Indonesia. The mine is located 1,530 kilometres east of the Indonesian capital Jakarta on Sumbawa, an island in West Nusa Tenggara Proviā¦The Batu Hijau mine is an open pit copper-gold mine operated by PT. Amman Mineral Nusa Tenggara. The mine is the second largest copper-gold mine in Indonesia behind the Grasberg mine of PT. Freeport Indonesia. The mine is located 1,530 kilometres east of the Indonesian capital Jakarta on Sumbawa, an island in West Nusa Tenggara Province, more precisely in the southern part of West Sumbawa Regency. The mine is the result of a ten-year exploration and construction program based on a 1999 discovery of the porphyry copper deposit. Production began in 2000.