(DIwida.Blog & News) -- Nestled within the mountain ranges of Arizona’s Sonoran Desert, where mercury can soar up to 118°F (48°C), lies an extensive mining operation over a hundred years old. This facility stands at the forefront as scientists strive to extract millions of tons of copper.
Following 154 years of excavation Morenci All the readily extractable copper has now been extracted. What remains are massive heaps of discarded rocks containing approximately 10 million tons of a metal deemed essential for worldwide electrification efforts. This resource could be pivotal in helping President Donald Trump achieve his aim of increasing domestic production of crucial minerals.
Freeport-McMoRan Inc., the owner of Morenci, is working on developing technology capable of drilling into massive waste heaps to recover low-grade copper that was once considered too costly and complex to process. Although this innovation is still in its early stages, the American corporation believes it has the potential to ultimately obtain these materials more affordably, swiftly, and sustainably compared to conventional mining methods.
The technique referred to as sulfide leaching has long been familiar to copper mining operations. However, the renewed interest in this method arises due to the anticipated surge in global demand for copper driven by advancements in electrification and artificial intelligence. As the top player in the industry, BHP predicts an increase in copper usage specifically for data centers. sixfold by 2050.
Trump’s emphasis on increasing domestic copper production—“it’s high time for copper to return home,” he stated in February—has reignited hope that facilities located in regions such as Arizona may gain an edge over competitors based in places like Latin America, Africa, and elsewhere. Following Trump’s directive to the Commerce Department to examine U.S. imports of this material—a move seen as potentially leading to new tariffs—the price of copper surged significantly. This situation suggests that additional trade barriers might be imposed soon. weeks.
Last week, copper futures on New York's Comex reached an all-time peak as traders factored in the potential for significant U.S. import duties on the material. This anticipation led to a considerable increase, with U.S. copper prices rising by 26% so far this year.
In certain scenarios, sulfide leaching might serve as a viable option instead of constructing entirely new copper mines. Frequently, high expenses, prolonged permit processes, and community resistance deter firms from initiating large-scale ventures. Nowadays, shareholders lean towards encouraging mining companies to pursue mergers and acquisitions or increase returns rather than approve the development of new facilities.
Morenci stands as the biggest copper mine in North America, comparable in area to Brooklyn. Amidst processing plants and storage buildings, reptiles and organ-pipe cacti soak up intense rays under clear skies. Each pile of discarded material has been assigned its own designation and appears strewn across the location in conical forms. During a scorching day in September, a group comprising engineers, chemists, and technicians tested various methods involving high temperatures, pressurized air, and chemical agents aimed at extracting copper from these refuse heaps.
For a considerable period, we simply did not believe it was feasible to reclaim anything from here," stated Robert Pollock, the site manager for Morenci, as he looked upward at a refuse heap as large as a Manhattan skyscraper. "However, nowadays, with all this historic copper, we're setting our sights on retrieving it.
Major players such as BHP Group, Antofagasta Plc, and Rio Tinto Group—with its Nuton division—are also advancing efforts to adopt sulfide leaching techniques. Several companies have partnered with emerging firms like Jetti Resources and Ceibo, entities that assert significant progress in this area. Given the diversity in geological compositions across various copper reserves, these corporations are tailoring distinct technologies suited for their specific mine sites.
These businesses are concentrating on extracting copper from a challenging sulfide mineral known as chalcopyrite, often deemed hard to process or "leach." Jetti’s innovation seeks to leach these sulfides with minimal heating or crushing, processes that have generally made treating chalcopyrite so costly that it becomes impractically expensive.
Ceibo, supported by BHP and now collaborating with Glencore Plc, employs a technique that rapidly oxidizes chalcopyrite ores via electrochemical processes. This leads to enhanced extraction yields within less time. According to the company, their method has achieved an over 75% success rate in extracting copper from chalcopyrite—substantially surpassing conventional leaching techniques.
For many years, miners have processed the calcopyrite mineral to extract copper," explained Corby Anderson, who teaches at the Colorado School of Mines. "Copper hasn't simply been sealed inside some magical container. Nonetheless, current technologies aim to boost the extraction efficiency of copper from calcopyrite, a task that can be quite challenging.
For years, Freeport-McMoRan has employed leaching techniques at the Morenci mine to extract lower-quality copper, but recently they have begun testing new chemical agents to access additional copper deposits located much further down within their discarded material heaps. Based in Phoenix, the firm has managed to recover 100,000 tons of copper through sulfide leaching thus far. Their objective is to increase this yield to 400,000 tons by 2030, which would be sufficient to supply wiring for over 4.3 million electric cars.
"That's akin to the output of a significant copper mine anywhere," CEO Kathleen Quirk stated last year.
Despite the promising outcomes from sulfide leaching tests, this does not ensure overall success. Companies face challenges when trying to demonstrate that their methods will work effectively on an industrial scale, and many hesitate before committing significant funds to these innovative procedures. In private discussions, certain mining firms have expressed doubts about the practicality of some technologies and have negotiated intensely regarding partnership agreements and rights ownership.
At Escondida, a massive copper mine in Chile operated by BHP, the global mining corporation has been experimenting with various technologies to counteract the decline in copper quality that threatens to significantly reduce output over the coming years. According to their strategy, BHP anticipates potentially producing up to 55,000 tons of copper annually through the process of leaching.
BHP is currently evaluating its proprietary technology along with systems from Nuton and Jetti. However, these technologies present significantly varied results. Jetti’s solution has lower installation and operational expenses but provides just a minor boost in recovery rates. In contrast, Nuton’s approach entails higher initial costs yet substantially enhances recovery yields. According to BHP, they intend to reach a conclusion following 2027.
Freeport-McMoRan, which initially invested alongside BHP and Mitsubishi Corporation in Jetti, has distanced itself from the technology following its collaboration with the start-up at their El Abra mine in Chile. In an email responding to inquiries, they stated that they have ceased utilizing the company’s method as they focus on developing their own approach instead. Currently, Jetti’s technology is being employed for commercial purposes by Capstone Copper Corp. in the U.S.
Jetti possesses a distinctive and proven commercial technology for processing primary sulfide ores," stated CEO John Slaven. "Our process involves treating run-of-mine materials without requiring heat, grinding, or permits, resulting in the production of 99.99% pure copper directly at the mining location, generating zero tailings and using less water. Deployment can be completed within twelve months, providing substantial financial benefits.
"It will ultimately boil down to the economics," Anderson stated, adding that he is aware of earlier attempts to enhance copper recovery via sulfide leaching. Though these methods were technically possible, they did not prove to be economically practical.
Freeport’s leaching initiative aligns with a key objective central to Trump’s critical minerals strategy: generating employment opportunities.
The decrease in American mining and mineral processing led to job losses as these roles shifted to foreign nations where they could be performed more cheaply. In rural areas of the Southwest, significant advancements in technology are essential for sustaining older mines.
Pollock, who serves as the site manager for Morenci, spent his childhood in Clifton, which is about 4 miles (6 kilometers) away from Morenci in Arizona. This town was established during the late 1800s primarily to accommodate the miners and their families working at the nearby mine. Back then, mules were used to transport crates filled with ore up the mine’s dusty inclines. Similar to many areas around it, this community's economic well-being soon became deeply intertwined with the fortunes of the mining industry.
Currently, Morenci contributes to approximately 13,000 direct and indirect employment opportunities and generates over $1.5 billion in overall economic advantages across the state, as reported by Freeport.
“I find it truly remarkable to see how much this place has transformed over the years,” stated Pollock. “ Undertaking this work ensures that the mine will continue to be operational for many more years to come.”
--Assisted by Thomas Biesheuvel and James Attwood.
(Includes statement from the company in the 20th paragraph.)
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