Minnova’s C$76M PL gold mine restart: economics and strip risks for engineers
Reviewed by Joe Ashwell

First reported on MINING.com
30 Second Briefing
Minnova plans a C$76.2 million restart of the brownfield PL gold mine near Sherridon, Manitoba, targeting 62,200 oz per year over 10 years from a high‑grade open pit feeding an existing 1,000 t/d plant, which is slated to double to 2,000 t/d in year two. The September resource stands at 3.76 million measured and indicated tonnes at 4.98 g/t Au (601,158 oz) plus 1.67 million inferred tonnes at 3.78 g/t (202,810 oz), with open pits carrying a high 21:1 waste‑to‑ore strip ratio. At US$3,000/oz gold, the PEA projects an after‑tax NPV5 of US$180.6 million, 111% IRR, eight‑month payback and all‑in sustaining costs of US$2,288/oz, but value falls sharply at lower prices, underlining cost and strip sensitivity.
Technical Brief
- Open-pit design carries an extreme 21:1 waste-to-ore strip ratio, driving haulage and unit cost risk.
- New plan pivots from the 2017 feasibility’s underground-focused, five-year schedule to a longer open-pit–led mine life.
- Historical 2017 study projected 46,500 oz/y at US$942/oz AISC, assuming US$1,250/oz gold and excluding inferred resources.
- September resource drilling campaign totalled 13,500 m in 131 holes, aimed at both expansion and confidence upgrade.
- Open-pit component currently defined as 1.58 Mt measured and indicated at 5.28 g/t Au (268,091 oz).
- Existing environmental licence only covers underground mining, so Minnova must secure amendments for open pits and new declines.
- Site, formerly Puffy Lake, previously operated December 1987–March 1989, implying legacy workings and potential geotechnical/rehab constraints.
- Economic sensitivity is extreme: a 20% gold price drop to US$2,400/oz reduces after-tax NPV5 to only US$5 million.
Our Take
With a C$19 million market valuation against an after-tax NPV of about $180.6 million at $3,000/oz gold, Minnova’s PL gold mine in Manitoba screens as a high-leverage, high-risk equity in our gold project coverage, which may appeal more to specialist funds than generalist institutions.
The 21:1 waste-to-ore strip ratio at the PL open pits is at the upper end of what operators in our database typically tolerate for small Canadian gold projects, suggesting that any cost inflation or productivity underperformance could quickly erode margins unless the underground component or grade control outperforms expectations.
The move from a 5-year mine life in the 2017 feasibility study to a 10-year production period in the latest assessment puts PL more in line with mid-tier Manitoba gold assets in our database, which can improve financing prospects but also raises the bar for demonstrating long-term geotechnical and permitting robustness near Sherridon.
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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