Sierra Madre buys Del Toro silver mine: restart schedule and capex notes for engineers
Reviewed by Joe Ashwell

First reported on MINING.com
30 Second Briefing
Sierra Madre Gold & Silver is acquiring First Majestic’s 100%-owned Del Toro silver mine in Zacatecas for up to $60 million, with $30 million due at closing (US$20 million cash, US$10 million in shares) and two further US$10 million milestone payments tied to a >100 million oz AgEq resource and achieving commercial production within five years. Del Toro comprises three fully permitted underground mines, a 3,000 t/d flotation plant and 62.5 km of existing development over 21.6 sq. km of concessions, with historic resources of 7.57 million oz AgEq (M&I) and 11.18 million oz (inferred). Sierra Madre plans ~50,000 m of drilling, an updated resource by early 2028, and a staged restart from mid-2027, while keeping open an accelerated restart within 12 months if silver prices stay strong.
Technical Brief
- Del Toro’s processing plant is a 3,000 t/d flotation circuit, already built and fully permitted.
- Underground infrastructure includes over 62.5 km of existing development across three permitted mines.
- Historic production averaged 2.54 million oz AgEq per year between 2015 and 2018 before shutdown.
- Operations were placed on care and maintenance in January 2020 to improve portfolio cash flow margins.
- Del Toro was originally commissioned by First Majestic in 2013 as its fifth producing silver mine.
- Sierra Madre must complete a C$40 million private placement at C$1.30/share as a closing condition.
Our Take
The staged US$60 million structure and C$40 million private placement mean Del Toro will compete directly with La Guitarra and the San Jorge copper-gold project for Sierra Madre’s capital, effectively prioritising near-term silver ounces in Mexico over advancing its Argentine copper-gold exposure.
Historic resources of 7.57 million oz measured and indicated plus 11.18 million oz inferred at Del Toro versus a 100 million oz silver-equivalent trigger for the contingent payment signal that Sierra Madre is betting on substantial exploration upside or reclassification of mineralisation rather than simply restarting on the existing resource base.
With three fully permitted underground mines and 62.5 km of development already in place at Del Toro, Sierra Madre’s indicated 12‑month ‘fast-track’ restart option is unusually short compared with most silver entries in our database, suggesting the main gating items will be financing and silver price levels rather than permitting or new infrastructure.
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.
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