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Stillwater (PGM)


LOCATION: Montana, United States
OPERATOR: Sibanye-Stillwater

The Stillwater complex is comprised of the Stillwater mine and East Boulder mine in Montana and is operated by Sibanye-Stillwater, following the acquisition of Stillwater Mining Company by Sibanye Gold Limited in May 2017. Production began in 1986 at the Stillwater mine and in 2002 at the East Boulder mine. Both are PGM mines with the majority of production being palladium.

Franco-Nevada has a 5% NSR royalty on all commercially recoverable metals produced from 813 of the 995 claims that cover the Stillwater complex. The amount of the royalty is reduced by permissible “onward processing” deductions, which have averaged between 10-12% of revenue over the last several years.

Based on Franco-Nevada’s estimates, the NSR royalty currently covers over 95% of the Stillwater Mineral Reserves and 100% of the East Boulder Mineral Reserves. In recent years, the percentage of Stillwater complex production subject to Franco-Nevada’s royalty has increased above 90% as mining moves away from the shaft area.

PGM production for 2019 yielded 593,974 ounces versus 592,608 ounces in 2018, which included production from the Blitz project (discussed below). PGM production for 2020 is expected to range between 660,000-700,000 ounces.

The Blitz project, located east of the Stillwater mine and covered by the NSR, commenced production in October 2017. Ongoing successful definition drilling at Blitz yielded 2.0 million ounces of additional Mineral Reserves in 2019. Sibanye-Stillwater expects ten producing area/stopes to be commissioned at Blitz by the end of 2022, adding a projected 300,000 ounces of annual PGM production from 2022 onwards. In the near term, Sibanye-Stillwater is focusing on the Fill the Mill (“FTM”) project which involves an incremental expansion of mining and certain support facilities at the East Boulder Mine and Columbus Metallurgical Complex. With ramp-up commencing in Q4 2020, the FTM project is anticipated to add 40,000 ounces of annual PGM production.

Sibanye-Stillwater estimates that both the Stillwater and the East Boulder mines have mine lives in excess of 25 years based on existing Mineral Reserves. Significant Mineral Resources have the potential to increase mine life even further in the future.


  • Steady PGM producer in Montana
  • Blitz expected to increase PGM production by 50% by late 2021
  • Current Mineral Reserves support a long mine life
  • Significant Mineral Resource potential to increase mine life even further

2019 2018 2017
Revenue to Franco-Nevada ($ million) $ 39.8 $ 21.3 $ 20.6