"Bougainville"

"BOUGAINVILLE" (EN: "Bougainville"; RU: "Бугенвиль") is the mining enterprise within the Papua - New Guinea country. The enterprise develops (since the 1972) the Panguna copper-porphyric deposit (has been discovered during the 1964) on the Bougainville island.

The deposit is confined to the southern part of the massif of the hornblende quartzous diorites of the Pliocene age, which have introduced themselves into the stratum of the Miocene-Oligocene andesites ot the Kayeta series, which is embedded in the slightly inclined manner. The diorites have been breached by the stocks of the quartz-plagioclase porphyrites (there is associated with one of them the stockwork ore body). The ore venules (up to 2.5 millimetres) are filled by quartz, chalcopyrite, and bornite, with the increased contents of gold, pyrite, magnetite, hematite, and molybdenite. The reserves of the ore are 870 million tonnes (1974), with the average content of copper of 0.47%, of molybdenum of 0.007%, of gold of 0.53 grams per tonne, of silver of 1.73 grams per tonne. They distinguish at the deposit the zone of oxidation (the thickness is up to 70 metres), and the zone of the secondary beneficiation (the thickness is up to 75 metres). The ore deposition is overlain by the sedimentary depositions with the thickness of up to 60 metres. The deposit is being developed by the opencast method by the "Bougainville Copper Ltd." company. The excavation of the ore and of the overburden rocks is performed by the "power shovel" excavators, and by the single-bucket loaders, the transportation is performed by the heavy load automotive dump trucks. The annual extraction is 40 million tonnes of the ore, with the content of Cu of 0.55%. The beneficiation is of the flotation type, the production of copper within the concentrate (29.2% of Cu) is 147 thousand tonnes, the production of silver is 37 tonnes, the production of gold is 14 tonnes (1980). The concentrate is exported according to the long-duration contracts into Japan (50% of the entire export), West Germany (40%), and so on.