The study sets the initial investment costs for surface mining of 4 million t / y at $ 294 million, with sustaining capital of $ 196 million.

At a discount rate of 8%, the after-tax net present value is $ 380 million and the internal rate of return is 41.8%.

The new study improves the after-tax payback period to 1.4 years by 3.6. It also has a lower life overhead content of 0.83% compared to 0.95%. The study used consensus copper prices of $ 3.80 per pound in 2024, $ 3.95 per pound in 2025, and $ 3.40 per pound thereafter.

Cash costs per pound of copper are expected to be $ 1.36 per pound. During the first five years of mine life, when production is expected to be 35,000 tonnes per year (compared to the average mine life of 27,000 tonnes), cash costs will be only $ 1.12 per pound.

Ero has started detailing the engineering of the project, located in the southern state of Para, and the first construction work could begin in the first half of 2022, if the council gives its approval.

In a statement, Ero CEO David Strang said he was excited about the results and that the project was the latest example of the company creating value from its existing portfolio.

“We started the reassessment of Boa from scratch, starting with a comprehensive review of mineral resource calculations which identified significant upside opportunities on which to build a new vision for Boa,” he said. “By re-recording the core, focusing our efforts on geological modeling and mine sequence optimization, we were able to identify a superior mine plan capable of supporting a much larger operation by advancing high-grade mineralization in the production plan. “

Boa Esperanca’s proven and probable reserves total 43 million tonnes grading 0.83% copper for 356,600 tonnes of copper.

The company also sees additional exploration potential on the project. In the short term, he is targeting the Gap zone, a target zone inside the shell of the pit that appears to be limited in drilling.

In addition to Boa Esperança, Ero owns the MCSA copper production complex in the northeast of the state of Bahia, Brazil, and the NX Gold mining complex in the state of Matto Grosso.

(This article first appeared in the Canadian Mining Journal)