Gunnison Copper Announces That Rio Tinto's Nuton Technology Produces First Copper
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The December 4, 2025 news release announces that Rio Tinto's Nuton technology has successfully produced its first copper cathode at Gunnison Copper's Johnson Camp Mine (JCM) in Arizona. This marks a critical operational milestone for a demonstration project targeting approximately 30,000 tonnes of refined copper over four years. The company highlights that Nuton's bioleaching technology offers high recovery rates (up to 85% from primary sulphides) and a lower environmental footprint. Both Rio Tinto and Gunnison Copper executives lauded the achievement, emphasizing the speed of development (18 months from concept to production) and the technology's potential to strengthen the U.S. domestic copper supply chain.
This news is materially positive and represents a significant de-risking event for Gunnison Copper. The successful production of copper using Nuton technology validates the company's key strategic partnership with Rio Tinto, a global mining major.
Reviewing the historical news provides crucial context: - Execution Track Record: Gunnison has consistently met its stated timelines throughout 2025. They guided for JCM production to begin mid-year, achieved first conventional copper production in late August, and first sales in September. They also guided for first Nuton copper "later this year," a target they have now met. This track record of delivering on promises builds management credibility. - Strategic Importance: While the conventional oxide production at JCM established Gunnison as a producer, the real prize is the large sulphide resource at the flagship Gunnison Project. The successful deployment of Nuton's sulphide-leaching technology is the crucial first step to proving that this larger resource can be economically unlocked. - Financial Context: This operational success comes just days after the company announced the full repayment of the US$7.3 million non-convertible portion of its Nebari secured debt (December 1, 2025). This, combined with the C$13.1 million financing closed in October, has significantly strengthened the company's balance sheet. Positive operational news makes the company more attractive for future financing needs related to the larger Gunnison Project.
While this is a "demonstration project" and not yet full-scale commercial production, it proves the technology works on Gunnison's ore at an industrial scale. This was a key milestone the market was waiting for, and its successful achievement should be viewed as a major step forward in the company's development.
Gunnison Copper is a multi-asset, pure-play copper developer and producer focused on its land package in the Cochise mining district in Arizona, USA.
- Johnson Camp Mine (JCM): The company's producing asset, restarted in 2025. It has a nameplate capacity of 25 million pounds of copper cathode annually from conventional heap leaching of oxide ore. JCM is also the host site for the industrial-scale demonstration of Rio Tinto's Nuton bioleaching technology for sulphide ores.
- Gunnison Copper Project: The company's flagship asset, a large-scale development project envisioned as a conventional open-pit, heap-leach operation. The November 2024 PEA outlined robust economics, including an after-tax NPV of US$1.3 billion and an average annual production of ~170 million pounds of copper over its first 16 years. The project has the potential to supply up to 8% of recent U.S. annual domestic copper production.