Anglo-Australian mining giant Rio Tinto on Wednesday said it would invest US$749 million to expand production at one of its iron ore mines in Australia's remote Pilbara region.

The firm said the cash would be spent on a new crusher and 13-kilometre (eight-mile) conveyor system at the Western Turner Syncline Phase 2 mine, part of its Greater Tom Price operations in Western Australia state.

The miner claims the conveyor will help lower greenhouse gas emissions from the mine by 3.5 percent compared with transporting iron ore by road.

Rio has committed to reduce its carbon footprint and advocate for policies aimed at limiting climate change.

It is also "continuing to assess additional options to reduce emissions, including renewable energy solutions", it said in a statement.

Construction is due to start early next year -- pending final government approval -- with first iron ore expected from the crusher in 2021.

All of the mine's trucks will also be fitted with autonomous driving technology by 2021 as part of the project.

Rio Tinto iron ore chief Chris Salisbury said the investment was part of a "pipeline of high-quality, low-cost options that will underpin production... well into the future".

According to the company's website, it has 16 iron ore mines and four ports in the Pilbara, where it says it is expanding operations to "epic proportions".