The Batu Hijau mine is an open pit copper-gold mine operated by Newmont Mining Corporation's subsidiary company PT Newmont Nusa Tenggara (PT Newmont). The mine is located 1,530 kilometres (950 mi) east of the Indonesian capital Jakarta on Sumbawa, in southern Taliwang Regency, an island in West Nusa Tenggara. 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.
The mine utilizes a "truck and shovel" open-pit mining method, with ore reporting to semi-Autogenous Grinding and ball mills, followed by a flotation circuit. The finished product is a thickened copper-gold concentrate, which is shipped via pipe to a storage facility on the Indonesian coast.
The orebody at Bata Hijau is porphyry copper and includes a high gold component, which is common for a copper deposit in southeast Asia. The host rock for porphyry copper deposits in southeast Asia is typically diorite and quartz-diorite. Copper sulphides such as chalcopyrite and bornite are frequently associated with the gold component of these deposits. As of the end of 2005 the remaining ore reserves at the Batu Hijau included 2.77 million tonnes of copper with an average grade of 0.69g/t gold, which would allow mining to continue until 2025.
Mining & Milling :
Batu Hijau is an open-pit mine. Ore is removed from the mining face using P&H 4100 electric shovels (pictured) and loaded into Caterpillar 793C haul trucks. Each haul truck can move a payload 220 t (240 short tons) of ore. The trucks haul ore from the shovel to primary crushers. Crushed ore is sent by a conveyor 1.8 m (6 ft) wide and 6.8 km (4.2 mi) long to the mill. Daily production from the mine is an average of 600,000 t (660,000 short tons) ore and waste combined. Ore from the mine has an average copper grade of 0.49% and an average gold grade of 0.39g/t.