It pays to look at a problem from a different angle.
After acquiring the Chilean copper projects Escalones and Cristal from TriMetals Mining in 2019, World Copper (TSXV: WCU) spent much of 2020 reviewing core photos, assays and core logs for evidence that the sulphide copper mineralization was enriched by secondary copper oxides, sulphates and carbonates, which would result in higher grades at shallower depths.
“We noticed that at Escalones a lot of the higher grade copper was in the oxide layer, so we started some metallurgical tests to see how amenable it would be to heap leaching, and lo and behold we found that we had a substantially large deposit that is suitable for leaching,” World Copper CEO Nolan Peterson told Chilexplore Group.
Leach tests in the first half of 2021 then confirmed how much of the deposit would be acid-soluble, leading to a new inferred resource estimate – constrained to the oxidized supergene mineralization within the pit shell – of 426mt copper oxide. This in fact makes it Chile’s largest copper oxide project currently in exploration and development, in terms of copper contained, Peterson added.
As a result of these studies, World Copper has been able to move forward with the project’s PEA
much sooner than if it had stuck with the previous owner’s plan to process the asset as a sulphide project. The PEA is scheduled for completion and publication in January 2022.
“As a sulphide project, which it was just five months ago, there would be no PEA in discussion. For these same tonnages and grades it would simply be too small or too low grade, it would need to become larger. But now as an oxide project it has a very compelling path to future development,” Peterson affirmed.
An oxide project doesn’t require a tailings storage facility, it’s much cleaner and greener (using less water and emitting less CO2 per tonne of copper produced), it’s easier to permit, requires significantly lower initial capital and significantly lower operating costs, resulting in a higher margin, Peterson clarified, adding that a sulphide project has a much longer project payback time and can run to around US$4bn construction costs while heap leaching should require about US$500mn initial outlay.
The previous owner prepared a scoping study internally many years ago but didn’t publish it because as a sulphide project it wasn’t viable, Peterson noted.
WORLD’S GREENEST CU PROJECT
As if the new approach alone wasn’t enough to put the project in a good light, one of the most compelling points for prospective investors is World Copper’s plan to use the latest technologies for clean processing, and the relatively low power requirements at Escalones.
“We have gravity on our side for much of the mining. That opens up a lot of opportunities for, electric equipment that other mining projects around the world do not have, making it more efficient thanks to regenerative breaking. Also, we’re starting to see cathode from oxide projects attracting premiums from companies that want green-sourced copper,” the executive explained.
Also, Peterson believes this greatly improves the firm’s chances of getting the eventual project “approved and across the finish line”, no matter which candidate would be voted in as Chile’s president
“We trust that Gabriel Boric and his administration will engage in an open and respectful dialogue with the mining industry, to help us operate as a business that wants to create jobs and opportunities, profits for shareholders and [benefits] for local communities. I do think that in the end the Chilean electorate is very moderate. So I don’t think it’s a real long-term concern, but there may be things that we have to navigate a little bit and then adjust to new circumstances and regulatory changes. We’re positioning ourselves to build the world’s greenest copper project, which I think will resonate very well,” he concluded.
Each of the five porphyry targets
has the potential to be as large as
the main Escalones target
FIVE PORPHYRIES TO EXPLORE
In October 2021, surface sampling confirmed a cluster of three distal copper targets, dubbed Rio Negro, Argüelles Este and Argüelles, some 8km northeast of the main Escalones deposit.
And Escalones itself remains open to expansion to the south, east and west, most notably the obvious Mancha Amarilla lithocap immediately to the south, which represents an undrilled area roughly the same size as the known deposit.
“Each of those copper porphyry targets has the potential to be as large as the main Escalones target, by volumes involved,” Peterson asserted.
Mancha Amarilla is the priority target, for which World Copper has earmarked US$2mn-2.5mn in exploration during 2022, since it could prove to be an extension of the main deposit.
The immediate focus is to gain knowledge and eliminate elements of risk in the project so that the forthcoming PEA shows the true potential of the asset.
“We’re going to just establish the footprint for all the deposits on Escalones, see if there’s anything more interesting that would catch our attention to the northeast, or refocus on the main resource and then do an infill drilling program to move the
project to pre-feasibility,” the executive explained.
The Cristal property, close to the border with Peru, brings a fifth porphyry into the mix, which should also be subject to drilling in 2022.
Previous owners ran geophysical surveys over several years until 2012, identifying coincident aeromagnetic low, gravity high, and extensive EM high anomalies, all measuring several kilometres across and suggesting a buried porphyry.
“Those anomalies suggest there’s high potential for attractive mineralization there and it’s a relatively simple plan. We just need to drill two or three holes to 500m or 600m below the cover, with a drill program planned for later in 2022,” Peterson added.
This year, a private placement originally aimed at raising US$4mn was oversubscribed and finally closed in October with US$6.5mn raised, leaving World Copper with a cash position that is “enough to advance our drill programs, and our exploration and development programs in early 2022.”
The Escalones PEA will fall mostly within the 2021 budget, but Peterson noted that the 2022 budget will include a PEA update for World Copper’s Arizona property Zonia, being acquired through a merger that should close by year-end.