Awakening the power of two sleeping giants across two continents is critical for Rio Tinto to access future higher-grade iron ore exports.

The world's biggest iron ore producer will increase output capacity at its newest mine in Western Australia's Pilbara region by 16 per cent to 50 million tonnes annually, at a cost of $130m, as analysts predict its return to record production levels by 2025.

Rio reported a 1.2 per cent rise in its third-quarter iron ore shipments on Tuesday, helped by a production ramp up at its $3.1 billion Gudai-Darri mine, which reached its targeted annual capacity of 43m tonnes well before schedule in its first year of operation.

The company continues its push to improve the grade and quality of its exports, with only 12.5 per cent of Rio's shipments for the June quarter containing lower grade products, such as its SP10 blend, compared to almost 17 per cent in the corresponding 2022 quarter.

The planned ramp-up of production at Gudai-Darri will feed growing global demand for iron ore from traditional and emerging markets such as India.

It also maintains Rio Tinto's position as a viable and reliable partner as it banks on two sleeping giants Simandou in Guinea, West Africa and Pilbara's Rhodes Ridge site - tipped as Australia's best undeveloped iron ore prospect.

The Rhodes Ridge project is a joint venture with Wright Prospecting and would cement Rio's iron ore division from 2030, with the site containing 6.8 billion tonnes of 61.6% iron ore, close to existing infrastructure and the potential for longer-term production capacity of more than 100 million tonnes a year.

Once the mine enters production it will restore Rio's production of higher-grade Pilbara Blend to levels better than 85 per cent of its total shipment volumes.

Rio's SP10 grades 58 to 60 per cent iron ore, below the 62 per cent average of benchmark export quality ore, and will likely be a significant portion of its total exports until Rhodes Ridge enters production close to 2030.

The company said improvements at its Gudai-Darri site near Newman on Banjima Country include greater use of autonomous assets, such as world-first driver-less water carts, autonomous trains, Rio's first rotable bucketwheel reclaimer, a robotic ore sampling laboratory, paperless field mobility, digital assets and a solar farm.

Rio Tinto Iron Ore managing director of Pilbara Mines, Matthew Holcz, said the company had learnt a great deal while analysing data from its mostly robotic mining fleet, sparking confidence to leverage the tech-driven asset while it waits to progress two massive iron ore projects in the Pilbara and in Guinea.

"What we have learnt during the rapid ramp-up of Gudai-Darri has given us the confidence to find better ways to increase capacity at our newest and most technologically advanced mine," he said.

"Rather than taking a capital-intensive approach to replicate existing infrastructure, we have now identified a low-capital pathway to creep capacity to 50 million tonnes a year."

The reporter viewed Rio Tinto's Pilbara iron ore operations as a guest of the company.