Rio Tinto looks at Argentine copper: adds projects in San Juan and seeks participation in Taca Taca

Argentina, with five of the world’s largest undeveloped copper projects in its territory, was at the center of that strategy. One of those initiatives is Los Azules, from the Canadian firm McEwen Copper, in San Juan, where Rio Tinto participates with 17.2% through Nuton LLC, its technology unit.

Another project that may be part of the strategy is Taca Taca, the copper giant in Salta, where Rio Tinto appears as one of the candidates to buy a minority stake which wants to sell the Canadian First Quantum Minerals.

Not all are great projects, Rio Tinto too invested US$15 million to retain an initial stake of around 5% in Mogotes Metals, the Canadian company that controls 100% of the Filo Sur project, an initiative that is part of the Vicuña District, the same strip that houses Filo del Sol and Josemaría, today in the hands of the partnership between BHP and Lundin Mining.

Río Tinto comes to this copper play with an already consolidated presence in Argentina through lithium. The company bought Arcadium Lithium in 2025an operation that gave it control over key assets in Catamarca and Jujuy.

Also, it has Rincón, in Saltawhich was the first mining project to obtain approval from a RIGI in May 2025 by US$2,744 millionand sustains its development with strong investments, including a financing of US$1,175 million secured in March of this year.

Since May, industry sources indicated that Rio Tinto evaluates increasing its participation in Los Azules. Michael Meding, managing director of McEwen Copper, himself put it clearly: The mining company “has the mandate to add copper production to his productive profile”, which led to conversations that he described as fruitful.

Meanwhile, for Filo Sur, Rio Tinto obtained a 15-month exclusivityextendable for six more months, with the right to match any offer from a third party for the project, and a “top-up right“which would allow it to reach up to 9.99% of the shares. Mogotes remains the operator and retains full ownership, but Rio Tinto secured the key to the door before anyone else can touch it.

Unlike Los Azules and Filo Sur, in Taca Taca, the Salta copper project, Rio Tinto does not start from a previous position. Here it is First Quantum Minerals looking to sell minority stake in one of the largest undeveloped copper projects in the world.

Rio Tinto appears as one of the candidatestogether with Japanese firms Mitsubishi and Mitsuiin a process that both parties describe as early stage, with no guarantees that it will lead to an agreement, as reported by Bloomberg.

The interest is not surprising: Rio Tinto and First Quantum are already partners in the La Granja project, in Peru, where First Quantum bought a majority stake that previously belonged to Rio Tinto in 2023 and both develop the field together.

It is the same pattern of cross association that the mining company has been repeating in different countries. Building a project the size of Taca Taca requires a capital of more than US$5 billionmaking alliances an increasingly common way to spread development costs and risks.