The Rhodes Ridge joint venture (JV) has approved a $191-million (A$294-million) feasibility study to progress the first phase of development at the Rhodes Ridge iron-ore project, one of the world’s largest undeveloped iron-ore deposits, in Western Australia’s Pilbara.

The study will assess the development of an operation with an initial production capacity of between 40-million and 50-million tonnes a year of iron-ore. The JV comprises Rio Tinto (50%), Mitsui (40%) and AMB Holdings (10%), with Rio Tinto’s share of the feasibility spend amounting to $96-million (A$147-million).

In addition to the feasibility work, the partners intend to invest a further $146-million (A$225-million) in exploration between 2026 and 2028 as part of the broader study programme. The feasibility study is expected to be completed in 2029.

Rio Tinto Iron Ore CEO Matthew Holcz said the project had the potential to play a long-term role in the miner’s Pilbara operations. “In partnership with the Nyiyaparli Traditional Owners, we are working to develop Rhodes Ridge, which, given its size and quality, has the potential to underpin Rio Tinto’s Pilbara iron-ore business for decades to come,” he said.

“Earlier this year the joint venture welcomed Mitsui into the project, confirming Rhodes Ridge as one of the best undeveloped iron deposits in the world. We are excited to keep working with all our partners as we progress the feasibility study.”

The JV said it would continue to work closely with the Nyiyaparli Traditional Owners throughout the mine life cycle, guided by the recently updated native title agreement’s engagement framework. This will include measures to protect and manage cultural heritage and the environment.

Environmental considerations are also being incorporated into the project design, with the JV seeking to minimise disturbance and reduce long-term closure impacts.

The move to feasibility follows Mitsui’s announcement earlier this year that it would acquire a 40% interest in the project. Rhodes Ridge is planned as a staged development, with the current investment focused on phase one. An initial production hub is likely to be located in the northern part of the project area and would leverage Rio Tinto’s existing rail, port and power infrastructure.

Subject to regulatory approvals, first ore from the initial development, located about 40 km north-west of Newman, is expected by 2030.

Rhodes Ridge has a potential capacity of about 100-million tonnes a year of high-quality iron-ore and is expected to support Rio Tinto’s strategy to achieve and sustain mid-term Pilbara iron-ore capacity of between 345-million and 360-million tonnes a year.