Underground decline portal at the Endeavor mine near Cobar NSW. Source: Proactive Investor
Polymetals (ASX: POL) has commenced a fresh phase of operations by bringing silver and zinc production back online at the Endeavor mine—an established polymetallic site situated about 40 kilometres north of Cobar in regional New South Wales. Once Australia’s second-largest underground polymetallic mine, the site now boasts a fully commissioned processing plant, underground infrastructure upgrades, and early concentrate shipments—marking a major milestone in the company’s regional mining strategy .
Mining Infrastructure and Processing Capabilities
The Endeavor mine is equipped with extensive underground access via a 7-kilometre decline, supported by a vertical shaft, onsite crushing and dewatering systems. Above ground, the site houses all essential facilities—administration blocks, labs, maintenance workshops, staff housing, and a connection to the regional power grid.
Its centerpiece is a 1.2 Mtpa processing plant, equipped with two-stage crushing, three ball mills, flotation circuits for zinc and lead, as well as thickeners and filtration systems. Conveyor access, sealed roads, and rail connectivity are also fully functional .
1806-0Commissioning achieved full wet processing of crushed ore by late May. Underground operations are steadily ramping, bolstered by stockpiles exceeding 40,000 t of ore. Polymetals plans to process around 65,000 t of ore per month during the second half of 2025, with first commercial shipments of zinc concentrate expected in early July—likely from Berth 29, Adelaide, under an offtake arrangement with Ocean Partners .
Production Forecasts, Ore Grades and Financial Outlook
Over its first decade, the mine is forecast to yield roughly 260,000 tonnes of zinc, 90,000 tonnes of lead, and more than 10 million ounces of silver in concentrate form. Historical records reveal robust ore grades with past extraction having yielded high-return metals .
2630-0The processing plant and mine redevelopment are expected to generate annual EBITDA of around AUD 89 million during the first five years, contributing to a pre-tax IRR of 345 per cent and NPV of AUD 414 million. Total pre-tax free cash flow is estimated at AUD 609 million.
Project Ramp-Up Timeline & Workforce Dynamics
2937-0After acquiring the mine in 2023 and taking full ownership via a revised purchase agreement in May 2024, Polymetals secured funding—including AUD 35 million from share placement—to accelerate development . 3235-0The workforce has grown from a core team of six to around 60 employees, with expectations to reach roughly 230 by full ramp-up .
3396-0Mine management has prioritized efficient in-house development. Executive Chairman Dave Sproule hailed the rapid progress in commissioning grinding and flotation circuits, while General Manager Matt Gill celebrated the efficient crushing, hoisting and early stockpiling of high-grade silver ore—highlighting an underground ramp-up ahead of schedule.
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Logistics, Offtake and Regional Integration
3780-0Ore processed at Cobar will be shipped via rail to Berth 29 in Adelaide for export. An offtake agreement with Ocean Partners secures early revenue via pre-paid zinc concentrate in June, with first shipping expected in July 2025 .
4113-0In addition, Polymetals has forged a strategic alliance with Metals Acquisition Limited to treat high-grade zinc ore at Endeavor and share water resources. This partnership also extends mineral synergies across the wider Cobar Basin .
Risks, Exploration Upside and Future Growth
4368-0Surface and underground exploration programs are already underway, particularly targeting the Carpark prospect south of the main mine. These efforts aim to expand the estimated 16 Mt resource base and potentially extend mine life beyond the initial ten years.
4720-0While global commodity price fluctuations remain an external risk, the mine benefits from existing infrastructure, strategic funding, and experienced personnel. A deferred rehabilitation bond extension, secured through 2026, further supports regulated operations.
Conclusion: Polymetals’ Strategic Revival of Cobar’s Backbone
Polymetals’ relaunch of the Endeavor mine marks a critical success in revitalizing one of Australia’s richest polymetallic sites. With a commissioned processing plant, secured offtake, solid financial metrics, and a clear path to commercial production, the company is executing its vision of becoming Australia’s next major silver and zinc producer. Supported by local partnerships, strong regional logistics, and further exploration upside, the project stands poised as a cornerstone of future Australian base-metals output.
