SolGold PLC's preliminary economic assessment for the Alpala copper-gold-silver deposit, part of its 85%-owned Cascabel property in Ecuador, outlined a net present value of US$4.1 billion to US$4.5 billion, discounted at 8%, and an internal rate of return of 24.8% to 26.5%.
The estimates are based on mine production cases ranging from 40 million tonnes per annum to 60 mtpa, according to a May 20 release.
Preproduction capital expenditure is estimated at US$2.4 billion to US$2.8 billion with a payback of 3.5 to 3.8 years.
Annual metal production is expected to average 150,000 tonnes of copper, 245,000 ounces of gold and 913,000 ounces of silver in concentrate during the mine's life of between 49 and 66 years.
The study is based on a mineral resource estimate at Alpala of 2.95 billion tonnes at 0.52% copper equivalent containing 10.9 Mt of copper and 23.2 million ounces of gold, at a cutoff of 0.2% copper equivalent.
A pre-feasibility study for Alpala is expected in December, based on an updated resource estimate. A definitive feasibility study is scheduled to be complete at the end of 2020.
SolGold had said it was considering a conditional hostile all-share takeover bid for Cornerstone Capital Resources Inc. to secure full ownership in the Cascabel project.