Mining giant Rio Tinto is to invest more than $1bn at its iron ore operations in Australia and Canada.

It has approved a $US933M investment to extend the life of the Marandoo iron ore mine by 16 years to 2030 and given a further $US277M to increase the Iron Ore Company (IOC) of Canada's concentrate production capacity by 40% to 26Mt/y

The Marandoo mine is part of the Anglo-Australian miner's operations in Western Australia's Pilbara region. It is 35km north east of the town of Tom Price.

The project will extend the Marandoo mine life at its current mining rate of 15Mt/y by developing the adjacent reserves below the water table.

At the same time, Rio Tinto said it has agreed to invest more cash in its Canadian iron ore joint venture. This is the second phase of a three stage expansion that was announced in May 2010.

Phase two of the project will increase IOC's spiral and magnetite concentrate production capacity by an average of 1.3Mt/y to 23.3Mt/y from 2013.

Recent studies have highlighted an opportunity to improve time to market through bringing forward some capital items from the third stage, resulting in higher level of production earlier.

The third stage of the planned expansion to 26Mt/y is currently under study and a final decision is expected by 2012.

The Iron Ore Company of Canada is the nation's largest iron ore producer and is 58.7% owned by Rio Tinto.