World number one miner BHP Billiton on Monday bought additional exploration plots near its Olympic Dam mine and expansion project from Minotaur Exploration.
The $180 billion behemoth paid A$9.5 million cash plus its 41% interest in another joint venture with Minotaur for five tenements in the same geological zone as Olympic Dam.
Olympic Dam is one of BHP's most ambitious projects and the giant copper-gold-uranium-silver project in South Australia's outback is set to become the world's biggest open pit.
BHP has already received government approval for the mammoth $30 billion expansion of Olympic Dam and the company's board will make a final decision on the project this year.
The planned open pit mine would be adjacent to the current Olympic Dam underground operation.
An idea of the olympian effort required to construct the mine and the size of the undertaking is clear from the fact that trucks will haul overburden 24/7 for five to six years just to reach the ore body.
The combined operations would mine 72 Mt ore per year and would produce 750,000 tonnes refined copper, 19,000 tonnes uranium oxide, 800,000 gold ounces and 2.9 Moz of silver per year.