Mine Workings
The workings include a very large open pit mine, an underground mine and four concentrators. The open pit mine – which forms a mile-wide crater at the surface – is a high-volume, low-cost operation, producing more than 67 million tonnes of ore and providing over 75% of the mill feed in 2006.
Ore undergoes primary crushing at the mine, before being delivered by ore passes to the mill complex for further crushing, grinding and flotation. Grasberg’s milling and concentrating complex is the largest in the world, with four crushers and two giant semi-autogenous grinding (SAG) units processing a daily average of 240,000 metric tonnes of ore in 2006.
A flotation reagent is used to separate a copper-gold concentrate from the ore. Slurry containing the copper-gold concentrate is delivered by three pipelines to the seaport of Amamapare, over 70 miles away, where it is dewatered. Once filtered and dried, the concentrate – containing copper, gold and silver – is shipped to smelters around the world.
The facilities at the port also include a coal-fired power station, which supplies the Grasberg operations.
Read more about this topic: Grasberg Mine
Famous quotes containing the word workings:
“So much of truth, only under an ancient obsolete vesture, but the spirit of it still true, do I find in the Paganism of old nations. Nature is still divine, the revelation of the workings of God; the Hero is still worshipable: this, under poor cramped incipient forms, is what all Pagan religions have struggled, as they could, to set forth.”
—Thomas Carlyle (1795–1881)
“Standards of conduct appropriate to civil society or the workings of a democracy cannot be purely and simply applied to the Church.”
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