Rio Tinto and Chile’s state-owned mining company Empresa Nacional de Minería (ENAMI) have signed a binding agreement to establish a joint venture to develop the Salares Altoandinos lithium project in the Atacama region of Chile.
The JV will see Rio Tinto acquire a controlling 51 per cent interest in the project, with ENAMI holding the remaining 49 per cent.
The Salares Altoandinos project is located in one of Chile’s most mineral-rich areas, with the Atacama region expected to become a world-class copper and lithium district pending further studies.
This lithium project is estimated to contain more than 15 million tonnes of lithium carbonate equivalent, making it a significant asset in the global supply chain for critical battery materials.
Rio Tinto will contribute up to US$425 million in cash and non-cash investments to the joint venture. This investment includes the deployment of Rio Tinto’s proprietary direct lithium extraction (DLE) technology.
The cash contributions will fund a pre-feasibility study and subsequent technical evaluations, with staged spending contingent upon the JV passing investment stage gates.
The transaction is targeted to close in the first half of 2026, subject to all customary regulatory approvals and closing conditions.
The formation of the JV follows a competitive selection process initiated by ENAMI in August 2024, which shortlisted six companies — BYD Chile, CNGR Advanced Material, Eramet Chile, LG Energy Solution, POSCO, and Rio Tinto. After a thorough evaluation, Rio Tinto was confirmed as the preferred partner in May 2025.
Sinead Kaufmann, Chief Executive of Rio Tinto Minerals, emphasised the strategic importance of the project and the company’s commitment to sustainable development: “We are continuing to execute our strategy of building a world-class lithium portfolio to position Rio Tinto as a global leader in the responsible supply of critical minerals essential to the energy transition.
“The Salares Altoandinos project represents a significant opportunity to develop a large-scale, long-life, low-cost lithium brine resource.
“We are committed to the highest environmental standards and to ensuring any potential development is guided by transparent, respectful and ongoing engagement with local communities in Chile’s Atacama region.”
ENAMI has indicated that if productive and market conditions are met, the Salares Altoandinos project could generate more than $15 billion for Chile throughout its lifecycle.
This joint venture marks a significant step in Rio Tinto’s aggressive expansion in lithium, complementing its recent acquisitions and reinforcing its goal to become a leading supplier of critical minerals necessary for the global energy transition.
The project aims to commence operations potentially by 2032, contributing significantly to both Chile’s mining sector and the global lithium supply chain.
