Canadian Mining Journal


COPPER: Excelsior begins construction of Gunnison project

The copper oxide minerals in the naturally fractured ore at Gunnison are mostly on the fracture surfaces. (Image: Excelsior Mining)

ARIZONA – Vancouver-based Excelsior Mining Corp. has begun construction of the 100% owned Gunnison project in anticipation of the first copper production by the end of 2019. This is an in situ copper project located about 100 km southeast of Tucson.

Forty-one production wells and 22 compliance wells will be drilled for a total of about 25,000 metres of drilling. Excelsior says the wellfield is designed to provide flexibility including reversing wells and adjustable flowrates to maximize copper production.

The processing facilities are being upgraded with enhanced controls and instrumentation, new rectifiers, and increased solution heating capacity. The changes will ensure that a 99.999% pure copper cathode is produced.

The Gunnison project is fully permitted and fully financed. The feasibility study projected an after tax net present value of US$807 million and an internal rate of return of 40% using US$2.75 per lb. of copper and a 7.5% discount rate.

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