Lower purchases grow zinc social inventories on weekend 

On April 30th, South32 raised the development cost estimate for the Taylor deposit at its Hermosa zinc-silver project in Arizona, US, and delayed the timeline. First-stage capital expenditure has increased by more than 50%, from $2.2 billion in the 2024 FS to $3.3 billion. First production has been delayed by one year to H2 FY2028, full production has also been pushed back to FY2031. Cost increase was mainly due to contractor underperformance, slower-than-expected construction productivity, scope changes, inflation, US tariffs and higher input costs. Progress on a key ventilation shaft is the main bottleneck now. But the company also noted that ore reserves at Taylor increased by 52%, mineral resources rose by 10%, extending the expected mine life from 28 years to around 33 years.