Arizona’s first new copper mine in more than a decade is close to becoming a reality. In September, Excelsior Mining announced that the Arizona Department of Environmental Quality (ADEQ) provided the company with a Grant Letter for its Copper Project’s Aquifer Protection Permit (APP), located in Cochise County, southeastern Arizona and on Oct. 12 the company announced that the mandated 30-day appeal period ended without an appeal for the project.
“The successful completion of this major milestone is yet another demonstration of the ability and experience of our management team, led by Stephen Twyerould,” said chairman of Excelsior Mining, Mark Morabito. “To complete the entire state permitting process well within a two-year timeframe is an accomplishment that few within the industry thought possible. With this permitting success, Stephen Twyerould and his team have moved Excelsior significantly closer to production, while the lack of an appeal to our permit highlights the strong community support enjoyed by our project.”
Twyerould, president and chief executive officer, added, “With the issuance of this final state operating permit, Gunnison remains on-track to become the next new copper mine in the United States. From the beginning, we have remained wholly committed to technical excellence and the highest environmental standards; these core values have served us well throughout the permitting process and will continue to guide us as we move into production.”
Excelsior continues to work with the federal Environmental Protection Agency toward the issuance of an Underground Injection Control (UIC) Permit, which is the last of the three key operating permits required. Excelsior expects a draft UIC Permit will be issued for public comment soon.
Excelsior wants to build Gunnison in three phases with initial capacity of 11,340 t/a (25 million lbs/year) which is expected to cost $47 million to build using an existing processing plant at the neighboring Johnson Camp mine. Excelsior bought the plant for $8.4 million in 2015. Gunnison could eventually reach 56.7 kt/a (125 million lbs/year).
The project utilizes in situ recovery (ISR) methods to leach copper from a copper oxide deposit and extract the copper by conventional solvent extraction-electrowinning (SX-EW) technology. Proven and probable reserves are pegged at 2.05 Mt (2.25 million st) of contained copper.