Strike to begin at Sibanye-Stillwater’s US operations

AI desk brief

Sibanye-Stillwater is heading into a strike at its Stillwater East mine and Columbus metallurgical complex in Montana starting 7 a.m. on Sept. 3 after more than four months of unsuccessful contract talks with the United Steelworkers. The work stoppage could hit about 750 employees across the mine plus recycling and smelting facilities, creating a near-term supply risk for US platinum group metals output.

The company said the production impact will depend on strike duration, operating arrangements, staffing availability and restart timing, but the affected assets are material to the group’s PGM footprint. Sibanye disclosed that the US mines produced 137,930 ounces in the first half of 2026, with Stillwater East accounting for 76,334 ounces, or about 55%, at an average of roughly 446 ounces/day.

For the PGM market, the strike is a constructive supply-side development for platinum and palladium if it lasts more than a few days, especially given the operational sensitivity of underground mining and smelting/recycling throughput. Near-term focus will be on strike duration, any partial workarounds, and whether the dispute escalates into a longer interruption that could tighten physical supply and support nearby prices.