South32 updates on project development and exploration

Hermosa project

South32 invested US$197M7 of growth capital expenditure at Hermosa in the September 2026 quarter, continuing construction of the Taylor zinc-lead-silver project (Taylor). In addition, lease payments for self generated power and other assets were approximately US$15M.
South32 progressed underground construction during the quarter, extending the decline and sinking the main and ventilation shafts. Both shafts are expected to reach the primary production level in the December 2026 quarter. We also advanced surface infrastructure construction, installing all flotation cells and major electrical transformers.
On 2 September 2026, the US Forest Service released a Final Mine Plan of Operations for Hermosa, completing the federal permitting process under FAST-41.
South32 invested US$7M in capitalised exploration in the September 2026 quarter, including exploration drilling at the Peake copper deposit. On 14 September 2026, South32 announced additional drilling results from Peake, including high-grade copper and polymetallic intercepts.

Ambler Metals project

The Ambler Metals joint venture (50% South32 share) completed its summer field season in the September 2026 quarter, drilling more than 5,000m at the high-grade Arctic polymetallic deposit to support development studies.
Federal permitting for Arctic under FAST-41 progressed during the quarter, with the US Army Corps of Engineers publishing a Notice of Intent to prepare an Environmental Impact Statement.
On 11 September 2026, we completed the previously announced sale of 8.2M shares in Trilogy Metals, our joint venture partner in Ambler Metals, to the US Government for US$17.8M12. We will reinvest the sale proceeds in Ambler Metals to support exploration and development activities.

Exploration

We invested US$6M in our greenfield exploration opportunities in the September 2026 quarter, progressing multiple exploration programs targeting base metals in highly prospective regions.
We invested US$21M (US$20M capitalised) in exploration programs at our existing operations and development options in the September 2026 quarter, including US$7M at our Hermosa project (noted above, all capitalised), US$3M for our Sierra Gorda EAI (all capitalised) and US$1M for our manganese EAI (nil capitalised).