Papua New Guinea’s largest gold producer, the Porgera mine, is situated in the Enga Province in the highlands of PNG. The Porgera Joint Venture comprising Placer Dome (50%), GoldFields (RGC) Ltd (25%) and Orogen Minerals (15%). The remainder is split between the Porgera landowners, the MRDC and the Enga provincial government. The open pit operation produced 23 t of gold (more than a third of PNG’s production) in 1998. 2.8t of silver were produced as well. Proven and probable reserves at the mine are estimated at 104 Mt grading at 3.6 g/t, equivalent to 12 Moz gold.
The OK Tedi Mine is situated at Mount Fubilan in the Star Mountains in western PNG, close to the Indonesian border. The OK Tedi Mining Company Ltd. (OTML) is owned by BHP (52%), Inmet Mining Corp. (18%) and the PNG government (30%). OTML has been at the focus of several tailings pollution claims and as a result, BHP is reviewing its position in OTML. Of the government’s 30%, 2.5% is allocated to mine landowners. OTML is one of PNG’s largest export earners, contributing 20% to PNG’s exports in 1998. OK Tedi produced approximately 152 000 t of copper in concentrate, 413 000 oz gold (13 t) and 839 000 oz silver in 1998. Ore resources are estimated at 344 Mt grading at 0.88% copper and 0.92 g/t gold.
PNG’s newest gold mine development has been the Lihir Mine, which was commissioned in 1997. The mine has an expected life of 37 years, with the intial 15 years based on the high grade open pit operation, with the remaining 22 on working low grade stockpiles. Due to the refractory nature of the ore at Lihir, a whole ore pressure oxidation procedure is used followed by standard CIL. The first full year of production was in 1998, producing 520 000 oz gold. Lihir is a publicly listed company, whose main shareholders are Southern Gold (of which Rio Tinto owns 75%) – 22.8%, Niugini Mining Ltd – 17%, Mineral Resources Lihir 10.3% and the balance by private and institutional investors. Ore resources are estimated at 500 Mt grading at 2.65 g/t gold – equivalent to 43 Moz in the ground.
Placer Dome also a major interest (80%) in the Misima Mine, located on Misima Island in the Milne Bay Province, eastern PNG. Similar to that of Lihir, Misima has a high grade open pit operation, which is to be followed by the processing of low grade stockpiled material. Orogen Minerals Ltd owns the remaining 20% in the mine. Misima produced just under 6t of gold and 18t silver in 1998 from its proven and probable ore reserves that contain 930 000 oz gold (28t) and 8.8 Moz silver (264t).
The Tolukuma Mine is situated in the remote Central Province in the Owen Stanley Mountains and is owned and operated by Dome Resources. Dome has been subsequently acquired by Durban Roodepoort Deep (DRD), a major South African producer. Tolukuma is a high grade – low tonnage mine with reserves and resources estimated at 909 000t grading at 22 g/t gold and 93 g/t silver (1998). The mine produced 2.3 t of gold and 170 kg of silver in 1998 at a cash cost of A$263/oz. The operation has also been dogged with environmental problems, with a minor cyanide spill from one of its helicopter deliveries.
Projects that are undergoing feasibility studies are the Simberi gold project, situated in the Tabar Islands. Simberui is owned by Australian Nord Pacific who anticipate a 40 000oz gold per year production. The Morobe gold project is situated in the Wau are of the Morobe Province, where the first large scale gold was discovered in PNG. Aurora Gold and the Commonwealth Development Corp. (CDC) are owners of the project. Although PNG has numerous copper and gold projects that are undergoing feasibility studies, future mine developments will have to take a more integrated approach in addressing the social and environmental impact of mining in PNG.
Placer Dome Inc.
Placer Dome is actively involved in two large scale gold mines in Papua New Guinea; viz. The Porgera Mine (Placer Dome 50%) and the Misima Mine (Placer Dome 80%). Silver and copper are also produced as by products from both mining operations.
Rio Tinto Ltd
Rio Tinto has a 17% interest in the Lihir Gold Mine as well as an interest in the Bougainville copper gold mine in Papua New Guinea.