Tharisa fires first underground blast in shift to deep mining

Tharisa Minerals fired its first underground blast at the Apollo portal on 31 March 2026, marking the formal start of underground development at its flagship chrome and platinum group metals mine near Rustenburg. The company had flagged the shift to underground bord-and-pillar mining the previous October as part of a plan to keep the mine productive long after its open pit is exhausted.

A $547m bet on longevity

Tharisa has committed $547m to the underground transition, including securing a separate R750m facility to fund the underground mining fleet. The company said the project remained on schedule and within budget as of mid-2026, with portal development on track to deliver first run-of-mine ore during the fourth quarter of its 2026 financial year — a slight delay from an initial second-quarter target — before reaching steady-state output of 255,000 tonnes a month by the third quarter of 2029.

Six decades of extra life

Tharisa says the underground operation could unlock at least 60 years of additional mine life beyond what the open pit alone would have allowed, transforming what was originally conceived as a finite open-pit operation into a multi-generation mining asset. That scale of extension is unusual in South Africa's chrome and PGM sector, where many operations are managing declining reserves rather than planning for a doubling or more of their operating horizon.

Why it matters

The shift underground is a capital-intensive undertaking that few chrome-focused miners can fund, reflecting Tharisa's position as one of the more financially resilient players in a South African chrome industry otherwise squeezed by high electricity costs. A successful transition would secure PGM and chrome supply, and the jobs that go with it, at the mine for decades to come.

What happens next

Investors will watch the fourth quarter of FY2026 for confirmation of first run-of-mine ore from underground, and subsequent years for the ramp-up toward the targeted steady-state production rate by 2029.

Sources

• Mining Weekly: Tharisa kicks off underground strategy with first blast, 01 Apr 2026
• Mining Weekly: Inside Tharisa's life-extending transition from openpit to underground mining, 22 May 2026

Photo: Rock from the Bushveld Complex near Rustenburg, South Africa, where Tharisa is developing an underground mine. James St. John, Wikimedia Commons, CC BY 2.0.