Excelsior Mining secures final permit to restart the Johnson Camp copper mine

Excelsior Mining’s Johnson Camp mine project in Cochise County, Arizona, which the firm bought from Nord Resources in December 2015. Credit: Excelsior Mining

Excelsior Mining (TSX: MIN) said on Monday it has received all permits to commence operations at its Johnson Camp copper mine in southeast Arizona. First copper production is anticipated in the first half of 2025, it added.

The amended and approved mined land reclamation plan (MLRP), along with the recently obtained air quality and aquifer protection permits, means that all necessary approvals for production at Johnson Camp have been received.

Excelsior has been looking to revive the historic open-pit copper operation with the support of Nuton, a Rio Tinto technology venture. Construction of the mine began in August following Nuton’s decision to proceed with Stage 2 of a work program in preparation for mining restart.

Under the companies’ agreement signed last July, Nuton intends to fully deploy its proprietary heap leach technology at the Johnson Camp site. In return, the Rio venture will pay Excelsior $5 million for the use of mine infrastructure and fund all of Excelsior’s costs associated with this stage.

Since the 1970s, the Johnson Camp mine has been a heap leach operation. It comprises two open pits, a two-stage crushing-agglomerating circuit and a fully functioning solvent extraction-electrowinning (SX-EW) plant capable of producing 25 million lb. of copper cathode annually.

Earlier this year, Nuton completed Stage 1 of the work program, consisting of mineralogy, predictive modelling, engineering and other test work. Meanwhile, Excelsior, as project operator, completed diamond drilling, permitting activities, detailed engineering and project execution planning.

The Stage 2 work is anticipated to take five years to complete. If successful, it would demonstrate key elements of Nuton’s technology at an industrial scale. It will then proceed based on milestones related to engineering and mobilization, infrastructure and construction, mining, leaching, copper production, and post-leach rinsing.

Upon completion of Stage 2, Nuton will have the right to form a joint venture on the Johnson Camp mine, in which Nuton and Excelsior will initially hold 49% and 51% respective interests.

Shares of Excelsior Mining were down 6.6% at C$0.17 apiece by noon ET in Toronto, for a market capitalization of C$53.6 million ($38.7 million).