ANTAM's Gold Mining
ANTAM's main gold and silver production is sourced from its underground gold mines at Pongkor, West Java and Cibaliung, Banten. Indications of gold deposits at Pongkor were discovered by ANTAM's Geology Unit in 1981, and production commenced in May 1994 after ANTAM secured the mining license in 1992. The Cibaliung gold mine was acquired in 2009 from an Australian company, Arc Exploration and began to operate in 2010. The Cibaliung mine is operated by ANTAM's subsidiary, PT Cibaliung Sumberdaya. ANTAM also owns 25% of PT Nusa Halmahera Minerals which operates the Gosong mine in North Maluku. At the beginning of June 2013 ANTAM received an extension of forest borrow and use license for Pongkor gold mine until 2021.
ANTAM employs conventional and mechanized cut and fill method with jumbo drill and load haul dump (LHD) in its underground mining activity. The Pongkor mine has three primary veins of gold, all of which currently being mined: Ciguha, Kubang Cicau and Ciurug. Meanwhile the main gold veins in Cibaliung mine which are being currently mined are Cikoneng and Cibitung.
A mechanised cut and fill method, with hydraulic jumbo drill and load haul dump (LHD), was introduced in 2000 for the third vein, Ciurug. The use of mechanised cut and fill is intended not only to assist in meeting the increased production targets but also to lower overall production costs and to improve efficiency. Meanwhile, the Cibaliung mine is operated with a combination of mechanised cut and fill and undercut and fill mining methods. The gold ore at Pongkor and Cibaliung goes through various processes which include crushing, milling, cyanidation, carbon leaching and stripping, electro winning to melting and casting to produce bullion/ dore. The waste is processed at the detoxification plant to reduce the cyanide content of tailings to below the threshold limit value of 0.5 ppm, so that it can be safely used as a total tailing backfill system in combination with cement.
The dore/bullion from Pongkor and Cibaliung is then sent by armored vehicle to ANTAM's precious metals refinery, Logam Mulia, located in Jakarta. Please refer to the section Precious Metal Refining for further information on ANTAM's precious metal refining operation.
