How much it will cost Fortescue to produce a tonne of ore is the source of much debate in Australia's mining community.

ECONOMIST: Fortunes in the mining business come and go faster than ever

Port Hedland had closed three main iron ore ports in the Pilbara region, the world's largest source of iron ore, as the cyclone approached.

BBC: Australia hit by Tropical Cyclone Rusty

Unable to secure all the iron ore they need from Australia, a traditional source, traders in China have recently started to import from such places as Brazil.

ECONOMIST: On a roll