Gunnison Copper and Rio Tinto Achieve First Copper Production

Gunnison Copper Corp. announced that Rio Tinto has successfully produced its first copper using the innovative Nuton® Technology at the Johnson Camp mine in Arizona. This significant milestone, achieved in November 2025, marks a crucial advancement in the development of this cutting-edge copper processing technology.

The production follows over three decades of research and development, culminating in the creation of a copper cathode through Rio Tinto’s proprietary bioleaching process. This technique employs microorganisms cultivated on-site to facilitate copper extraction. The project aims to produce approximately 30,000 tonnes of refined copper over a four-year demonstration period, utilizing a specifically designed heap leach pad.

Katie Jackson, Chief Executive of Rio Tinto Copper, stated, “This is a breakthrough achievement for our Nuton technology, which is proving that cleaner, faster, and more efficient copper production is possible at an industrial scale.” Notably, this technology has reduced project timelines dramatically, achieving production in just 18 months compared to the typical 18 years for conventional projects.

Nuton Technology harnesses naturally occurring microorganisms to extract copper from primary sulphide materials, which have historically posed processing challenges. The microbes, cultivated in proprietary bioreactors, speed up mineral oxidation in crushed heaps, generating heat that allows copper to dissolve into a leach solution. This solution is subsequently processed into 99.99% pure copper cathode.

The integration of Nuton Technology eliminates the need for traditional steps like concentration, smelting, and refining, thus simplifying supply chains and delivering copper directly at the mine gate. It boasts recovery rates of up to 85% from primary sulphides, which are prevalent copper-bearing materials.

One of the technology’s key benefits is its potential to extend mine life and maximize resource utilization. By extracting value from materials typically classified as waste, Nuton can enhance yield and revenue at both existing and new mining sites. Furthermore, the environmental impact is notably reduced, with Nuton expected to use up to 80% less water and generate up to 60% lower carbon emissions compared to traditional methods.

At the Johnson Camp mine, Nuton aims to achieve the lowest carbon footprint for copper production in the United States. By acquiring 134,000 Green-e Energy certified renewable energy certificates, the site ensures that its electricity is entirely sourced from renewable energy. The anticipated carbon footprint for the copper produced is 0.82 kilograms CO2-e per kilogram of copper, significantly lower than the projected global average of 3.4 kilograms CO2-e per kilogram for operating copper mines in 2026.

Additionally, water usage is projected to be 71 litres per kilogram of copper, compared to the industry average of approximately 130 litres per kilogram.

Stephen Twyerould, President and CEO of Gunnison Copper, emphasized the collaboration between Gunnison and Rio Tinto, stating, “Achieving this level of performance in such a short time frame shows what is possible when innovation, operational excellence, and a shared vision come together.” He added that with Nuton copper entering the U.S. supply chain, this milestone underscores Gunnison’s role in enhancing access to cleaner, low-carbon copper.

While this initial production validates the engineering and operational aspects of Nuton, the next phase will involve long-term technical performance assessments. This will include multi-year testing, independent verification, and internal reviews by Rio Tinto to ensure consistent recovery rates and environmental standards.

Gunnison Copper Corp. is a multi-asset copper developer operating within the Cochise Mining District, which encompasses twelve known deposits. The flagship Gunnison Copper Project boasts a measured and indicated mineral resource of over 831.6 million tons, with a total copper grade of 0.31%. The preliminary economic assessment (PEA) for this project indicates robust economic potential, including a net present value (NPV) of $1.3 billion and an internal rate of return (IRR) of 20.9%.

As the mining industry increasingly focuses on sustainable practices, the success of Nuton at the Johnson Camp mine could pave the way for broader adoption of similar technologies in future projects, reinforcing the critical need for cleaner production methods in the copper supply chain.