Thor Explorations’ Douta PFS: project economics and mine design notes for engineers
Reviewed by Joe Ashwell

First reported on MINING.com
30 Second Briefing
Thor Explorations’ pre-feasibility study for the Douta gold project in southeast Senegal outlines a 12.6-year, two-phase open-pit operation producing an average 82,000 oz. per year, front-loaded to more than 400,000 oz. in the first four years from oxide and transitional ore. The study is based on 36.6 million tonnes of probable reserves at 1.03 g/t (1.2 million oz.) within a total indicated resource of 50.6 million tonnes at 1.04 g/t, and assumes project capital of $253.5 million. At a $3,500/oz. gold price, Douta delivers an after-tax NPV5 of $633 million, 61% IRR and sub-one-year payback, with a 40,000-metre 2026 drilling programme targeting additional oxide material at Makosa, Makosa Tail, Baraka 3 and nearby permits.
Technical Brief
- Phase 1 targets low-cost oxide and transitional ore, driving higher early throughput and margins.
- All-in sustaining cost averages $1,493/oz. in the first four years, rising to $1,890/oz. life-of-mine.
- Net cashflow over the first four years is estimated at $561 million after repaying $253.5 million capex.
- Updated indicated resource totals 50.6 Mt at 1.04 g/t (1.7 Moz), plus 9.3 Mt inferred at 0.92 g/t.
- First probable reserve stands at 36.6 Mt grading 1.03 g/t for 1.2 Moz contained gold.
- Mine life split: four years oxide/transitional, followed by 7.8 years of lower-grade fresh primary ore.
Our Take
With a project capital of US$253.5 million against an after-tax NPV5 of US$633 million and a 1-year payback, Douta sits at the high-return end of gold projects in our database, which may ease financing despite Senegal’s comparatively less established mine-finance track record than Nigeria where Segilola operates.
The 12.6-year mine life supported by relatively low-grade probable reserves at around 1 g/t gold suggests Thor Explorations is targeting a bulk-tonnage, throughput-driven operation at Douta, which will demand tight cost control on mining and processing to preserve the stated 61% IRR.
Thor’s evolution from Segilola in Nigeria (commercial since 2021) to a second asset in Senegal positions it as one of the few West Africa-focused gold operators in our coverage moving from single-asset to multi-asset status, which typically improves funding options but also raises execution risk around regional logistics and management bandwidth.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
Related Articles
Related Industries & Products
Mining
Geotechnical software solutions for mining operations including CMRR analysis, hydrogeological testing, and data management.
CMRR-io
Streamline coal mine roof stability assessments with our cloud-based CMRR software featuring automated calculations, multi-scenario analysis, and collaborative workflows.
HYDROGEO-io
Comprehensive hydrogeological testing platform for managing, analysing, and reporting on packer tests, lugeon values, and hydraulic conductivity assessments.
GEODB-io
Centralised geotechnical data management solution for storing, accessing, and analysing all your site investigation and material testing data.