Copper World will begin mining in Southern Arizona in 2029

Copper World will begin construction before the end of the year, and expects to begin mining for copper in 2029, following a partnership with Mitsubishi to back the massive open-pit project south of Tucson.

Toronto-based Hudbay Minerals Inc. has set up a partnership with Mitsubishi Corp., and is moving with the development of the mine in the Santa Rita Mountains, about 31 miles southeast of Tucson.

The project will become one of the largest open-pit copper mines in the U.S., the company has said.

Company officials said the project will create more than 1,000 construction jobs, and 500 permanent operating jobs, and generate $1.1 billion in tax revenues, including $362 million in local property taxes, and $200 million in Arizona state taxes over about 15 years.

The mine has faced a barrage of criticisms and legal challenges from environmental groups, who have argued the mine would seriously harm the Santa Rita Mountains and the Santa Cruz River, and destroy the northern half of the range in the Coronado National Forest.

The mine will include four “primary pits” across the range, as well as as supporting infrastructure, including waste rock facilities, a crushing system, ore stockpiles and a tailings storage facility.

The mine will also include a concentrate leach facility, which will produce copper cathode for the U.S. market.

“Backed by advanced engineering work, it has the potential to add approximately $377 million of additional after-tax net present value to Copper World,” Hudbay officials said this week.

“The final investment decision for Copper World marks the beginning of a new phase for the joint venture,” said Taro Abe, the chief operating officer for Mitsubishi’s critical minerals division. “We are pleased to move forward with the project and advance it toward first production in the second half of 2029.”

“Copper World is important to our growth strategy and the U.S. copper landscape, with the potential to deliver lasting benefits to communities and stakeholders,” Abe said.

Mitsubishi owns about 30 percent of the mine, part of a joint-venture agreement signed in January. As part of an investment decision, Mitsubishi said it would put $423 million into the project,

“The U.S. is the world’s second-largest consumer of copper, and steady demand growth is expected to continue, driven by population growth, increased power demand from generative AI and data center expansion, and the shift toward electrification,” said Mitsubishi officials. “In addition, the U.S. government has identified strengthening domestic supply chains for critical minerals, including copper, as a strategic priority.”

Copper was added to the “list of critical minerals” last year, one of 60 minerals considered “vital to the U.S. economy and national security that face potential risks from disrupted supply chains,” according to the U.S. Geological Survey.

Hudbay officials said Copper World will be “one of the largest open-pit” mines in the U.S., and begin operating by 2029. The mine will produce about 102,000 metric tons of copper over its first 10 years—11 percent more than previously assumed as part of a 2023 estimate.

The company estimated there is about 390 million metric tons of mineral reserves available for Copper World.

Hudbay originally sought to build the Rosemont Mine, planning a half-mile deep pit across nearly 2,500 acres in the Santa Rita Mountains.

However that effort faced fierce opposition from environmental groups who argued the mine and its tailings in the Coronado National Forest would bury thousands of acres within the range of the endangered northern jaguar and the ocelot, as well as nearly a dozen other endangered and critical plants and animals.

With that project moribund over legal challenges, Hudbay shifted its efforts to the western slopes of the Santa Rita Mountains on a chunk of private land once known as the Helvetia Mining District.

Hudbay said it could extend the mine’s lifespan by using federal land in 10 years as part of a second phase. The company said under FAST-41, an Obama-era system to fast-track federal permits, the mine could win federal permits in under three years.

South32’s Hermosa project won approvals under FAST-41, though in September, environmental groups filed a lawsuit arguing U.S. Forest Service and Fish and Wildlife Service “failed to meet their congressionally-mandated duties to protect species as required by the Endangered Species Act” by approving a plan for ancillary infrastructure in the Patagonia Mountains.

In May, Pima County Administrator Jan Lesher sent out a barrage of letters to investors, Canadian regulators and leaders at Mitsubishi warning about “unresolved risks” presented by the controversial open-pit mine project.

She said the county reviewed Hudbay’s 2023 pre-feasibility study, as well as state permit applications and other public documents, and found “unresolved risks that we believe warrant careful consideration from an investor disclosure perspective,” she said. This includes uncertainty on the available water supply and the impacts from the mine.

“The project relies on groundwater from a declining basin that is already causing subsidence and impacting well owners, and the proposed recharge is dependent on Colorado River allocations that are highly uncertain and are not occurring in the watershed of impact,” the county administrator wrote.

Lesher also warned the mine is expected to “alter groundwater flow, reducing flows to protected riparian systems, plants and wildlife.” And, she said proposed tailings storage areas are “upstream” of residential areas.

She added the mine faces ongoing litigation and “community opposition,” including opposition from tribal leaders creating a “sustained social and reputational risk to the project.”

Hudbay has faced fierce opposition over a planned half-mile-deep open pit across nearly 2,500 acres in Coronado National Forest, however, with that project jammed up over legal challenges, the company shifted its efforts to the western slopes of the Santa Rita Mountains on a chunk of private land once known as the Helvetia Mining District.

In September, Lesher urged Arizona officials to cancel a permit to pump and use groundwater for the mine, telling Department of Water Resources Director Aaron Buschatzke that pumping water for the open-pit mine would have harmful effects on nearby Sahuarita and Green Valley.