Adventus Mining (TSXV: ADZN; OTCQX: ADVZF) and Salazar Resources (TSXV: SRL; OTCQB: SRLZF) have released a feasibility study for an open pit mine and 1,850 t/d mill at their Curipamba copper-gold project in central Ecuador. Copper, zinc and lead concentrates with precious metals credits will be produced. Salazar is the operator and earning a 75% interest in the project.
The feasibility study includes a first reserve estimate, an updated resource estimate for the El Domo volcanogenic massive sulphide (VMS) deposit. DRA Americas headed the team that prepared the report, using prices of US$$1,700/oz. gold, US$23/oz. silver, US$3.50/lb. copper, US$0.95/lb. lead, and US$1.20/lb. zinc.
The Curipamba project has an after-tax net present value with an 8% discount of US$259 million and an internal rate of return of 32%. The pit has an estimated life of 10 years and will generate an estimated undiscounted cumulative after-tax cash flow of US$495 million over the fist six years of operation.
Average annual production would be 10,463 tonnes of copper or 21,390 tonnes of copper-equivalent over the life of the mine.
The initial capital cost for the pit and mill is US$248 million, and the sustaining costs are US$316 million. The all-in sustaining cost per lb. copper-equivalent would be US$1.26. The project would pay for itself in 2.6 years.
Open pit reserves are estimated at 6.5 million proven and probable tonnes grading 1.93% copper, 2.49% zinc, 2.52 g/t gold, 45.7 g/t silver, and 0.25% lead.
The total El Domo deposit has measured and indicated resources of 9 million tonnes grading 2.11% copper, 2.59% zinc, 2.36 g/t gold, 45 g/t silver, and 0.24% lead. The inferred category is 1.1 tonnes grading 1.72% copper, 2.18% zinc, 1.62 g/t gold, 32 g/t silver, and 0.14% lead.
Adventus and Salazar are also updating their underground preliminary economic assessment prepared for Curipamba in 2019. At that time, the underground indicated resource was 2 million tonnes grading 2.48% copper, 2.18% zinc, 1.25 g/t gold, 28.1 g/t silver, and 0.13% zinc. The inferred portion was 2.13% copper, 2.46% zinc, 1.60 g/t gold, 26.4 g/t silver, and 0.09% lead. These resources are independent of those for open pit mine.
The PEA projected an after-tax NPV with an 8% discount of US$49 million and a development cost of US$42 million. Average annual production in years 11 through 14 would be 20,000 tonnes copper-equivalent. (The same price assumptions were used as for the open pit.)