Transiting Voisey's Bay nickel mine from open-pit operations to underground will cost about $2 billion, and is expected to extend its productive life to 2035.
The battery cell maker is working on the first section of the factory, in Skellefteå in the north of Sweden, which will be completed in 2020 and produce eight gigawatt cell capacity per year.
The takeover offer, which expires next week, offers great exploration potential because Avanco owns a vast landholding in the copper and iron ore-rich Carajás region, second only to giant Vale.
