Unico Silver’s drilling strengthens the case for a January Joaquin PFS

January PFS reaches the final stretch

Unico Silver Limited (ASX:USL) has reached the point where geological promise must start becoming a mine plan. The company says its integrated maiden Pre-Feasibility Study for the Joaquin and Cerro Leon silver-gold projects in Argentina remains on track for release in January 2027, with process design, site layout and cost estimates now advancing in parallel.

“Joaquin – Infill drill results and Metallurgical and Geotechnical drill holes.”

The timetable matters because the study is expected to convert a large resource story into something more concrete: a pit-constrained Mineral Resource, a maiden Ore Reserve and the first formal production and funding assumptions. The current update follows the January PFS timetable shift, which moved the study from September 2026 to allow more drilling and metallurgical work.

Process flow diagrams for tank leaching and heap leaching are nearing completion, while capital and operating cost estimates are being assembled. Environmental baseline work is complete and an Environmental Impact Report is targeted for January, although neither the PFS nor the permitting milestone is guaranteed to land on schedule.

Infill drilling targets higher-confidence resource categories

The drilling results provide the immediate technical support for the study. At Joaquin, La Negra returned 7.7 metres at 1,410 grams per tonne silver equivalent from 38 metres, including 1.2 metres at 8,835 grams per tonne. At Cerro Leon, Marta Este delivered 28 metres at 355 grams per tonne silver equivalent from 22 metres, while Achen returned 9.5 metres at 489 grams per tonne from 81.6 metres.

“La Negra NW – infill drill results.”

Caption and image © Unico Silver Limited. From “PFS Update and Infill Drill Results”, 10 Nov 2026.

Unico says the infill program is expected to support conversion of Inferred Mineral Resources within the planned pit shells into Measured and Indicated categories. The results will feed a revised Mineral Resource scheduled for January, aligned with the study’s assumed recoveries, costs, metal prices and pit slopes. The reported intervals are downhole lengths, however, and true widths have not yet been established.

Metallurgical work is also doing more than filling an appendix. Historical processing of La Morocha ore, current testwork and heap-leach column testing are being used to compare two processing routes. Remaining risks and testwork requirements are expected to carry into the Definitive Feasibility Study, meaning the January document will narrow the development choices but will not settle every technical question.

Exploration adds upside beyond the PFS envelope

Alongside the resource-conversion drilling, Unico has identified mineralisation outside the current resources. At La Morena, east-west gold-bearing veins returned 36 metres at 122 grams per tonne silver equivalent from 17 metres, while a deeper hole returned 17.55 metres at 134 grams per tonne. At La Morocha NE, a shallow hole intersected a new silver-dominant vein with 5 metres at 242 grams per tonne silver equivalent.

“La Morena – Exploration drill results”

“Joaquin and Cerro Puntudo surface targets coloured by the sample media. Target IDs correspond to Table A4-1.”

The company’s second announcement gives that exploration program a larger shape: 55 surface targets were defined from 19,406 BLEG, soil and rock-chip samples across Joaquin and Cerro Leon. Nine have been ranked for priority follow-up, including the La Morena to Lineamiento Oeste corridor, Cerro Puntudo’s Sector Suroeste, the Isla Zone and Sierra Blanca. Surface rock chips are selective samples and indicate mineralisation rather than economic grade, so these targets remain a pipeline rather than a resource.

Cash supports the next campaign, but development funding is unresolved

Unico held A$100.2 million in cash at 30 September and says it is fully funded for the PFS, the RIGI application and its planned FY27 exploration and development program. The balance follows the A$60 million placement, which was intended to fund drilling and feasibility work.

The company is preparing an application for Argentina’s Large Investment Incentive Regime, with inclusion targeted for the second half of 2027. The proposed investment plan must meet a US$200 million minimum threshold for mining projects, and approval is not assured. More immediately, the PFS will determine how much capital the project requires and how Unico proposes to fund construction after the current cash runway ends.

That leaves January as the key test. Stronger resource classification and additional discoveries can improve the starting position, but the decisive numbers will be the Ore Reserve, recoveries, mine schedule, capital intensity and operating costs. Until those figures arrive, Joaquin and Cerro Leon remain an increasingly well-drilled development proposition rather than a defined mine.