By Charles Pitts
SAN JUAN, Argentina : Rio Tinto is actively evaluating an increase to its current 17.2% stake in McEwen Copper’s Los Azules project, according to industry reports and statements from project leadership. The move highlights a deepening commitment from the world’s second-largest miner to secure high-scale copper assets in South America to meet projected demand surges from the electric vehicle (EV) and artificial intelligence (AI) sectors.
The Los Azules project, located in the San Juan province of Argentina, is currently held by McEwen Copper, a subsidiary of McEwen Mining (NYSE: MUX). Discussions between Rio Tinto’s copper leaching venture, Nuton, and McEwen Copper are described as “ongoing” and “productive,” signaling a potential shift in the project’s ownership structure as it moves toward a 2026 construction start.
Strategic Alignment and Nuton Technology
Rio Tinto’s interest in Los Azules is inextricably linked to its proprietary Nuton leaching technology. Nuton has already deployed approximately $100 million into the project to secure its current minority position. The technology is a key pillar of the Los Azules 2025 Feasibility Study, which outlines a 21-year base-case mine life.
Unlike conventional copper processing that requires massive concentrators and smelters, Nuton’s technology allows for the heap leaching of primary copper sulfides. This process is expected to yield several operational and environmental advantages:
- Extended Mine Life: While the base case is set at 21 years, Nuton’s primary sulfide leaching could extend the project’s lifespan by 30 years or more.
- High Recovery Rates: Test results at the site indicate copper recovery rates exceeding 76% from primary mineralization.
- Lower ESG Footprint: The leaching process uses significantly less water and energy per tonne of copper produced compared to traditional methods, aligning with McEwen Copper’s goal of achieving carbon neutrality by 2038.
“Rio Tinto is building its copper pipeline and has a clear mandate to add production,” said Michael Meding, Managing Director of McEwen Copper, in a recent briefing. The integration of Nuton technology provides Rio Tinto with a technical “moat” and a flagship reference site for its venture.
Copper Price Forecast 2026: Market Drivers
The exploration of a larger stake comes at a time when mining news is dominated by long-term supply deficits. Major financial institutions have updated their copper price forecast 2026 to reflect the increasing pressure on global inventories.
| Institution | 2026 Copper Price Forecast (Avg) | Primary Driver |
|---|---|---|
| Goldman Sachs | $10,710 / t | Grid and power infrastructure growth |
| S&P Global | $12,100 / t | Supply tightness and concentrate shortages |
| Deutsche Bank | $12,125 / t | AI data center and hardware demand |
| RBC Capital Markets | $12,700 / t | Slowing supply growth post-2025 |
| J.P. Morgan | $13,500 / t (Peak) | Operational disruptions at major mines |
The demand side is increasingly bolstered by the acceleration of AI and data center infrastructure, which requires massive upgrades to electrical grids and power distribution systems. Combined with the electrification of the global transport fleet, analysts suggest that Tier-1 assets like Los Azules are becoming essential for “super-majors” looking to maintain market share.
Argentina’s Regulatory Shift: The RIGI Factor
A critical catalyst for Rio Tinto’s renewed interest is Argentina’s Large Investment Incentive Regime (RIGI). This legislative framework, championed by the administration of President Javier Milei, provides long-term fiscal and regulatory stability for projects exceeding $200 million in investment.
Los Azules was admitted to the RIGI program in 2025, granting the project:
- Tax Stability: A 30-year guarantee on corporate and export tax rates.
- FX Access: Improved access to foreign exchange for debt servicing and dividend payments.
- Duty Exemptions: Waivers on import duties for essential capital goods and mining machinery.
These reforms have significantly lowered the “country-risk discount” traditionally applied to Argentine assets. For Rio Tinto, the RIGI framework provides the necessary security to consider multi-billion-dollar capital commitments in a jurisdiction that was previously viewed as volatile.
Mining Stocks to Watch 2026: Ownership and IPO Plans
For investors tracking mining stocks to watch 2026, the ownership structure of McEwen Copper is a complex but lucrative puzzle. As of the current reporting period, the breakdown is as follows:
- McEwen Mining (MUX): ~46.4%
- Stellantis (STLA): ~18.3%
- Rio Tinto (Nuton): 17.2%
- Rob McEwen (Individual): ~13%
Stellantis, the global automotive giant behind brands like Jeep and Ram, has also invested heavily to secure long-term copper offtake for its EV production lines. The interplay between a major miner (Rio Tinto) and a major consumer (Stellantis) creates a robust financial foundation for the project.
McEwen Copper has signaled plans for an Initial Public Offering (IPO) to fund the estimated $3 billion construction cost. An increased stake from Rio Tinto prior to the IPO could provide a significant valuation floor for the new entity, while also potentially diluting other shareholders if the investment is structured as a private placement.
Timeline and Operational Milestones
The Los Azules project is currently in a high-activity phase. Following the approval of the Environmental Impact Assessment (EIA) in late 2024, the project team is focused on finalizing the technical specifications for the SX/EW (solvent extraction and electrowinning) facility.
- 2026: Target start for project construction.
- 2029: Scheduled startup for the SX/EW plant.
- 2030: Expected date for “First Copper” production.
The project is designed to produce LME Grade A copper cathodes on-site, which reduces the logistical complexity of shipping concentrates to international smelters. This on-site production is particularly attractive to Stellantis and other OEMs looking for a vertically integrated supply chain.
Risks and Challenges
Despite the positive momentum, the path to production is not without obstacles. High-altitude mining in the Andes presents significant logistical challenges, particularly regarding winter access and infrastructure transport. Furthermore, while the RIGI provides a legal framework, the long-term political durability of these reforms through successive Argentine administrations remains a point of focus for Rio Tinto’s risk assessment teams.
The global competition for M&A deals in the mining sector is also heating up. Should Rio Tinto delay its decision, other diversified majors or state-backed enterprises could potentially move to challenge their position, given the scarcity of 100,000+ tonne-per-year copper projects.
Conclusion
Rio Tinto’s evaluation of an increased stake in Los Azules is a bellwether for the broader mining industry. It represents a convergence of three critical trends: the necessity of innovative technology like Nuton to unlock complex deposits, the shift toward pro-investment regulation in South America, and the relentless demand for copper driven by the global energy transition.
As the industry moves toward 2030, Los Azules stands as one of the few projects capable of moving the needle on global supply. For stakeholders in McEwen Mining and the broader copper market, the outcome of Rio Tinto’s “ongoing discussions” will likely dictate the pace of development for what is arguably Argentina’s most important mineral asset.
