Because the ore body is 350 m below the land surface at Olympic Dam, the underground method of mining is used. Since mining commenced in 1988, more than 200 km of underground tunnels have been constructed.
3D diagram showing the shape of the ore body, and the tunnels constructed for mining it.
The ore is mined using a technique called open stoping. Holes are drilled into the bottom of ore-bearing areas. The drill holes are then packed with explosives. Blasting fractures from 50,000 to 100,000 tonnes of ore-bearing rock, in a huge stope similar in size to a multistorey office block with the shape of an upside-down milk carton. Special front-end loaders called boggers then scoop up the fractured ore from access shafts below the stopes. The ore consists of large fragments and lumps of rock which are transferred onto trucks that can carry 40 tonnes per load.
In each load this underground ore train can haul about 300 tonnes of ore to the loading bay at the bottom of a shaft.
Once on the surface it is transferred by ore conveyer to a huge stockpile, to await processing.
This machine is a radial stacker, which can direct crushed ore from the mine onto various parts of the ore stockpile on the left of the photo.
