Resolution Copper says it has reached a major milestone with the completion of its multi-year, $200 million rehabilitation and deepening of the historic No. 9 Shaft, in Arizona, USA.
Originally constructed in 1971 by the Magma Copper Company in Oak Flat and operated as a production shaft until the mid-1990s, the refurbished and deepened shaft now extends to a final depth of 6,898 ft (2,102 m) underground, and measures 22 ft (6.7 m) in diameter. The completed No. 9 Shaft is now the second deepest single lift mine shaft in the US, behind only Resolution Copper’s No. 10 Shaft at 6,943 ft.
Rehabilitated and deepened from 4,800 ft to over 6,800 ft, the No. 9 Shaft now connects to the No. 10 Shaft, serving as ventilation and access for future underground development. Together, the network of underground mine workings form the backbone of the project’s next phase of underground development.
The proposed underground mine, a joint venture between Rio Tinto (55%) and BHP (45%), has the potential to be one of the largest producers of copper in North America – supplying up to 25% of US copper demand each year.
Vicky Peacey, President and General Manager of Resolution Copper, said: “Completing the No. 9 Shaft is a huge milestone and a testament to the dedication and expertise of our underground team and contracting partners. This achievement underscores what’s possible when American miners, homegrown talent from local communities including the Superior, Miami, Globe, San Carlos Apache Tribe, Hayden, Kearny and Winkleman, come together to do the job safely.
“While ongoing litigation continues to stall development, we are ready to advance this important copper project, enabling thousands of high-paying jobs, billions in economic development for rural Arizona and access to a domestic supply of copper essential to American security and modern infrastructure. The sooner the litigation delays stop, the sooner this project can move forward and the sooner Arizona and the nation will benefit.”
The recent shaft-sinking project also achieved two years without a single medical injury or lost-time incident, underscoring Resolution Copper’s strong commitment to safety, the company says. Over the course of the work, crews drilled nearly 14, 500 ft, poured more than 560 cu.yd (428 cu.m) of concrete, and installed nearly 140 yards of shotcrete.
“This accomplishment reflects years of planning, discipline, and teamwork between our people and partners,” Rob Tobin, Operations and Maintenance Manager at Resolution Copper, said. “Achieving this safely for more than two years without a recordable injury shows the professionalism and dedication of everyone who worked underground to bring No. 9 back to life in a modern way.”
Redpath USA, the project’s lead contractor, managed sinking and construction, supported by Globe-based Oddonetto Construction underground concrete and surface batch plant operations and logistics.
“We are proud of the innovative solutions developed in partnership with Resolution Copper, and Oddonetto Construction and the flawless safety performance achieved along the way,” Eric Stoll, Project Manager at Redpath USA, said. “Completion of the No. 9 Shaft shows what can be achieved when local companies and national partners work side by side with a shared commitment to safety and excellence,” said Kim Oddonetto, President.
Oddonetto Construction added: “This project demonstrates that with the right training and opportunities, we can build a skilled underground workforce right here in our communities, one that will help power Arizona’s future for generations to come.”
To date, more than $2 billion has been spent to develop and permit the project, including reclamation of the historic Magma Copper Mine site, sinking a second shaft to mining depth, rehabilitating an existing shaft and deepening to mining depth, extensive drilling and orebody testing, and the federal approval and public engagement process.
