Fortuna's Diamba Sud feasibility study confirms robust Senegal gold project

The study projects a 60% after-tax IRR and $1bn NPV at $3,500 gold, after the resource grew 73% on the back of a new discovery

RMRoy Mulenga

29 June 20262 min read

Fortuna Mining Corp released a feasibility study for its Diamba Sud gold project in south-eastern Senegal on 29 June 2026, confirming what the company describes as an economically robust, open-pit, carbon-in-leach gold mine. The study projects an after-tax internal rate of return of 60% and a net present value of $1 billion at a 5% discount rate, using a gold price of $3,500 an ounce, alongside average annual production of 116,000 ounces, including 158,000 ounces a year over the mine's first four years.

A resource that kept growing

The feasibility study followed a sharp increase in the project's resource base: indicated mineral resources rose 73% to 1.25 million ounces in an estimate released in February 2026, driven substantially by the newly identified Southern Arc zone, which alone contributes 367,000 ounces from 6 million tonnes grading 1.91 grams per tonne and is now the largest single deposit discovered at Diamba Sud. Compared with an earlier preliminary economic assessment, the feasibility study lifted average annual production guidance from 106,000 to 116,000 ounces.

Why it matters

Senegal has a smaller gold mining history than regional neighbours such as Mali, Burkina Faso and Côte d'Ivoire, and Diamba Sud stands to become one of the country's largest dedicated gold mines if it proceeds to construction. Fortuna, a mid-tier miner with existing operations in Latin America and West Africa, has allocated $100 million to the project in 2026, including $60 million for early works such as camp facilities and site infrastructure, signalling it is moving toward a construction decision rather than treating the study as a shelf document.

What happens next

With the feasibility study technical report filed in July 2026, Fortuna's board now has the basis for a final investment decision. The scale of the 2026 early-works spending suggests the company is positioning to begin fuller construction relatively soon after any formal go-ahead, rather than waiting for a separate extended permitting phase.