Polymetals Endeavor mine restart: rapid brownfield ramp-up lessons for engineers
Reviewed by Joe Ashwell

First reported on Australian Mining
30 Second Briefing
Polymetals Resources has restarted operations at the Endeavor silver–lead–zinc mine near Cobar, New South Wales, moving from voluntary shutdown to first concentrate shipments within weeks. The rapid ramp-up at the former CBH Resources underground operation, which includes a 1.2Mtpa processing plant and extensive existing tailings and pastefill infrastructure, relies on reactivating care-and-maintenance assets rather than new construction. For engineers, the case shows how brownfield polymetallic plants can be recommissioned quickly when underground access, power, and metallurgical circuits remain intact.
Technical Brief
- Restart focused on reactivating care-and-maintenance equipment, avoiding long-lead procurement and construction mobilisation.
- Example suggests brownfield polymetallic mining assets can be cycled quickly if core services remain intact.
Our Take
Among the 63 silver- and zinc-keyword pieces in our database, very few involve rapid restarts of previously shut operations in NSW, so the Endeavor silver-lead-zinc mine stands out as a rare example of near-term metal supply coming from brownfield capacity rather than new builds.
For Australian base metals projects in our coverage, NSW assets like Endeavor typically face tighter water, tailings and rehabilitation scrutiny than operations in more remote states, which can make a fast transition from care-and-maintenance to shipments operationally complex even when infrastructure is already in place.
Polymetals Resources appears in far fewer of our 605 Mining stories than larger Australian base metals producers, suggesting that a swift restart at Endeavor could materially change its profile with offtakers looking for diversified silver and zinc supply within Australia.
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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