Perth, May 4, 2026, 03:02 AWST
- South32 lifted expected Taylor project capex, or capital spending, to about US$3.3 billion, roughly US$1.1 billion above the level set at final investment approval.
- First production is now expected in the second half of fiscal 2028, with full designed output, or nameplate capacity, pushed to fiscal 2031.
- Analysts have questioned the revised economics, even as South32 says a bigger ore base extends the mine plan to about 33 years.
South32 Ltd starts the week facing a sharper test of investor patience after its Arizona Hermosa project reset, with analysts warning that a larger ore body may not fully offset a US$1.1 billion cost increase and a slower ramp-up at the Taylor zinc-lead-silver mine.
The issue matters now because Hermosa is one of South32’s main new-build growth assets in the United States, at a time when miners are trying to secure zinc, copper and manganese supply from lower-risk jurisdictions. The project also sits inside the U.S. critical minerals push: Reuters reported in March that Hermosa contains silver, zinc and manganese deposits and is part of the FAST-41 federal permitting programme, which is meant to speed reviews for nationally important projects.
South32 said Taylor’s expected growth capital expenditure had risen to about US$3.3 billion from US$2.16 billion at the February 2024 final investment decision. The company blamed added decline access, revised shaft construction costs, inflation, higher input costs for steel, piping, concrete and electrical items, and U.S. tariffs.
Chief Executive Graham Kerr said Taylor still had the potential to produce zinc, silver and lead over several decades. He also said measures to improve shaft construction productivity would “only partially mitigate” contractor underperformance.
The company’s stronger resource case is real. South32 said Taylor’s ore reserve rose 52% to 99 million tonnes and its mineral resource rose 10% to 169 million tonnes, extending the initial operating life to about 33 years from 28 years.
The timing slipped anyway. First ore via the Clark decline is expected in mid-FY28, first production in the second half of FY28, and full capacity in FY31, one year later than previously indicated.
The stock has not escaped the damage. South32 shares were last shown at A$4.12, down 4.63% from a week earlier, after closing at A$4.03 on April 30 when the update hit trading screens, Intelligent Investor data showed.
RBC Capital Markets analyst Kaan Peker said the better scale and resource confidence were “overshadowed” by the capex increase, delay and higher costs, Mining.com reported. BMO analyst Alexander Pearce said the update left Hermosa “essentially break-even” on the bank’s commodity price assumptions and cut his price target by 7%, while keeping a market perform rating. Mining
South32 is still pointing to returns. Its update put steady-state EBITDA, a profit measure before interest, tax, depreciation and amortisation, at about US$650 million a year and post-tax net present value, a discounted estimate of future cash flow, at about US$3.1 billion. At spot commodity prices, those figures rise to about US$800 million and US$4.5 billion.
The peer context is not kind to slow projects. BHP, South32’s former parent, is pushing deeper into copper exploration in Zambia as big miners hunt metals tied to power grids and electrification; South32’s difference is that Hermosa is already a U.S. mine build, which means the prize is closer but the execution bill is landing now.
But the downside is plain. Another slip in shaft work, a fresh tariff step-up or sustained freight and input-cost inflation could stretch the budget again, and South32 has already warned elsewhere in its portfolio that Middle East tensions were lifting global freight rates and raw material prices.
Permitting remains a swing factor, though recent steps have moved in South32’s favour. Reuters reported that the U.S. Forest Service issued a draft decision and final environmental impact statement in March that would allow Hermosa to expand from private land onto federal land, with a final decision expected after objection and review periods.
Investors now have a harder calculation: whether a 33-year mine life and future copper optionality at Peake are enough to absorb a slower payback and higher upfront spend. For South32, Taylor has not stopped being strategic. It has become harder to underwrite.
