South African gold miner Gold Fields has reported a 15% increase in mineral reserves at its South Deep gold mine, near Carletonville.
The company stated in its 2011 Mineral Resources and Mineral Reserves guide that the mine design optimisation and inclusion of additional areas, which were not previously planned, pushed the mine’s mineral reserves to 39.6-million ounces, compared with the 34.5-million reported in 2010.
Overall, Gold Fields’ South African mineral reserves increased to 61.1-million ounces, up from 60.2-million, on the back of the five-million-ounce reserve increase at South Deep and the inclusion of 2.9-million ounces at the West Wits tailings treatment project, besides others.
The mineral guide pointed to an 8% decrease in gold mineral resources, dropping to 160.2-million ounces, from the 173.8-million ounces reported in the comparative period in 2010. The company attributed the drop to pay-limit increases, resource cleanup and geology model changes as a result of new information.
Gold Fields commented in the report that its South African operations, which included South Deep, the Kloof-Driefontein Complex, near Carletonville, and the Beatrix gold mine, near Virginia, in the Free State, remained key to the company’s vision of being the global leader in sustainable gold mining.
Gold Fields, which has a number of operating mines and projects in Australia, South Africa, Peru and Ghana, reported that the total managed precious metal and gold-equivalent mineral resources across all the operations reached 234.4-million ounces and the mineral reserves equalled 85.1-million ounces.
The group’s South Africa-based operations accounted for 68% of the total mineral resources and 72% of the mineral reserves. Australia-based operations accounted for 4% and 5% of Gold Fields’ mineral resources and mineral reserves respectively, while the South America-based units held 3% and 7%. The West African region contributed 11% and 16% of the mineral resources and mineral reserves respectively.
The Damang gold mine and the Tarkwa gold mine, both based in Ghana, increased their mineral resources by 46% to 25.2-million ounces and their mineral reserves by 21% to 13.7-million ounces. This was mostly owing to an increase in the gold price, a planned additional carbon-in-pulp plant at Tarkwa and new discoveries at the Damang project – the Huni, Juno and Damang main pit.
Australia’s Agnew gold mine, 375 km north of Kalgoorlie, and St Ives gold mine, 80 km south of Kalgoorlie, collectively decreased its resource base from 9.6-million ounces to 9.2-million ounces, as depletion and an increase in costs hit. The total reserve, however, remained stable at 4.1-million ounces.
The Cerro Corona gold mine, in northern Peru, reported a 5% decrease in its resources to 7.7-million ounces on the back of depletion, a slight reduction in metal recoveries and the increased net smelter return cut-off.
However, the total gold equivalent reserve increased 15% from 5.3-million ounces to 6.1-million ounces.
Gold Fields’ growth projects, which accounted for 14% of the total mineral resource base, included the Arctic platinum project, in Finland, with a resource base of 12.2-million ounces of two platinum-group elements and gold; the Chucapaca project, in Peru, adding a 7.6-million ounce resource to the group’s assets; the Yanfolila project, in Mali, which contributed 740 000 oz of gold; the Talas project, in Kyrgyzstan, with a resource of 11.7-million gold equivalent ounces; and the Woodjam project, in Canada, with 1.06-billion pounds of copper resources, producing gold as a by-product.