The West Angelas expansion will raise production from 29 million tonnes per annum to 35Mtpa and will extend the mine’s life by around 13 years.

It will create around 290 jobs during construction, with the ongoing operations workforce expanding by 200 to a total 1300.

Rio is also expected to spend around $200 million increasing production at the Western Turner Syncline mine from 25Mtpa to 30Mtpa.

The development will create around 240 construction jobs and 30 permanent roles.

“These projects are part of Rio Tinto’s plans to increase its annual iron ore production in the Pilbara towards 360 million tonnes and demonstrate the ongoing commitment of the company and its Robe River joint venture partners to their WA operations,” WA Premier Colin Barnett said.

Both projects will require the construction of infrastructure, including haul and access roads, as well as communications and waste facilities.

Barnett said the brownfields developments signalled continued iron ore demand from China, with 2013 sales of $68 billion making it the state’s most valuable export.

West Angelas is located between Newman and Tom Price, while Western Turner Syncline is 35km northeast of Tom Price.

Rio Tinto shares were last trading 1.8% higher at $62.52.