Excelsior Mining's state operating permit for its proposed Gunnison copper project in Cochise County, Arizona, was not appealed, leaving the Canadian company one regulatory approval away from the start of construction on the state's first new copper mine in more than a decade.
The Vancouver-based company said Wednesday that a 30-day public comment period expired this week without anyone challenging the permit approved in early September by the Arizona Department of Environmental Quality for the mine.
"The state permit had a total of five comments and no appeal," JJ Jennex, Excelsior's vice president of corporate affairs, told SP Global Platts in an interview. "We are on our remaining permit, a federal EPA permit," he said, referring to an underground injection control permit the Environmental Protection Agency could award before the end of this year.
Jennex, who said his company had heard it is difficult to permit new mines in Arizona, added that Excelsior is "absolutely confident we're going to obtain the permits. We're the first new copper mine in the United States."
Arizona is home to 26 copper mines and 1,114 mining-related operations in total, according to Tim Evans, assistant state mine inspector in Arizona.
The Carlota open-pit mine in Gila County was opened more than a decade ago by Poland's KGHM Polska Miedz. The mine currently is in "care and maintenance" and is not producing copper, he said in an interview.
Evans said he expects either Gunnison or HudBay Minerals' proposed Rosemont copper mine to be the copper mine to begin production in the Southwestern US state. HudBay is based in Toronto.
Referring to the state operating permit, Mark Morabito, Excelsior's chairman, said in a statement, "To complete the entire state permitting process well within a two-year timeframe is an accomplishment that few within the industry thought possible."
Gunnison initially would produce about 25 million lb of copper annually, a figure that could be ramped up gradually to 125 million lb a year, which is the mine's full capacity. The copper concentrate would be processed through the company's adjacent Camp mine.
Gunnison, located about 65 miles southeast of Tucson, contains a mineral deposit, North Star, estimated at 4.9 billion lb.
Initial construction costs are estimated at US$46.9 million, with life-of-mine operating costs of 65 cents/lb.
Based on a US copper price of $2.75/lb, a feasibility study performed by Excelsior indicated a post-net present value of $807 during the mine's life.