Aris Mining rises on Soto Norte PFS results

[Ben Graham]

Aris Mining (TSX: ARIS) (NYSE-A: ARMN) has released a prefeasibility study (PFS) for its Soto Norte gold project in Colombia, outlining the characteristics of both a profitable and environmentally friendly mine operation. Its shares rose on the news.

The PFS, using a base case gold price of $2,600/oz., gave Soto Norte a 22-year initial mine life with total production of 4.3 million oz. gold, 18.8 million oz. silver and 84 million lb. copper. The metals will be mined from an underground reserve base of 20 million tonnes grading 7 grams per tonne (g/t) gold, 32.1 g/t silver and 0.2% copper.

From this production profile, the study calculated an after-tax net present value (at 5% discount) of $2.7 billion, an internal rate of return of 35.4%, and a payback of 2.3 years from the start of operations. The initial capital is pegged at $625 million, while all-in-sustaining costs are estimated at $534/oz. over the life of mine.

The PFS results sent Aris Mining shares to a new 52-week high of C$12.60 apiece. By midday, it had pulled back to C$12.53 with a market capitalization of C$2.54 billion ($1.84bn).

Scaled-down operation

An important change in the PFS, as Aris points out, is a new study design that reduces Soto Norte’s plant processing capacity to 3,500 tonnes per day from the 7,200 tonnes envisaged in the 2022 feasibility study. This would result in a small-scale mine operation, with production spread out over a longer mine life (from 11 years previously), with more emphasis on reducing environmental footprint.

About 20% of the capacity, or 750 tonnes, will be reserved to process material purchased from local community miners, providing a “safe, regulated alternative that removes mercury use and ensures proper tailings and water management,” the company said.

“The Soto Norte PFS outlines a project that balances scale, profitability, environmental stewardship and community input,” chief executive officer Neil Woodyer stated, hailing it as “one of the most attractive gold projects in the Americas.”

He highlighted the company’s plan to process material mined by local community groups will replace informal mills that pollute waterways with safe, licensed processing. “All mine water will be collected, treated and safely returned, safeguarding the Bucaramanga and regional water supplies and improving water quality in the local community mining areas,” he said.

Until Soto Norte’s processing plant is operational, some material can be processed at the company’s Segovia operations or Marmato complex in Colombia, both of which are currently in production. Aris aims to follow a similar “partnership” model implemented at Segovia for the Soto Norte project, which is currently held under a 51/49 joint venture with Mubadala.

With the PFS completed, the company will now proceed with environmental studies in preparation for a license application in early 2026.