Australian aluminium company South32 reported a 3% increase in alumina production in the December 2025 half year.
This was driven by record output at Brazil Alumina and steady volumes at Worsley Alumina, which successfully completed scheduled calciner maintenance.
Aluminium production rose by 2% during the same period, supported by Hillside Aluminium testing its maximum technical capacity.
Hillside Aluminium produced 362kt in the first half of FY26 as it continued to operate at its maximum technical capacity.
Operating costs at Hillside are expected to fall 14% compared to the previous half year due to lower alumina prices.
The company’s Brazil Aluminium smelter recorded a 16% saleable production increase for the half year to 74kt.
Despite this growth, production in the December 2025 quarter was below plan due to unplanned pot outages and external energy disruptions late in the period.
The smelter’s operator is planning to implement measures to improve stability and continue the ramp-up of all three potlines.
The report comes after the planned transition of the company’s Mozal Aluminium smelter in Mozambique to care and maintenance in early 2026, after efforts to secure a long-term electricity supply failed.
Ahead of the transition, Mozal recorded a 3% production decline in the December quarter as pot relining stopped and shutdown preparations commenced.
Chief Executive Officer, Graham Kerr, stated: "We continued to deliver consistent operating results, with FY26 production guidance maintained across our operated assets and first half operating unit costs tracking in line with guidance.
“Our consistent operating performance, combined with strengthening market conditions, enabled the group to maintain a strong financial position while investing in our high-returning growth options and delivering returns to shareholders.”
