Rio Tinto Ltd has defended its right to keep the giant Rhodes Ridge iron ore deposit, saying it is critical to its Pilbara expanion plans, while also announcing a $710 million expansion of other operations in the region.

Rio Tinto Ltd has defended its right to keep the giant Rhodes Ridge iron ore deposit, saying it is critical to its Pilbara expanion plans, while also announcing a $710 million expansion of other operations in the region.