South32 output flat at Hillside Aluminium, manganese down 7% amid load shedding impact

Tawanda Karombo

South32 reported steady saleable production at its Hillside Aluminium smelter for the quarter ended September 2025, despite ongoing load shedding by Eskom that continues to strain the operation.

The diversified miner said on Tuesday that production at Hillside Aluminium unit was unchanged at 181 000 tons for the quarter. The company noted that the smelter “continued to test its maximum technical capacity, despite the impact of load shedding.”

Full-year production guidance for Hillside Aluminium remains unchanged at 720 000 tons, although quarterly sales volumes declined 13% after a shipment was deferred to the December quarter.

Despite what South32 described as a strong start to the year, its manganese production from South Africa dropped from 593 000 wet metric tons in the previous quarter to 551 wet metric tons in the September quarter.

However South32 raised overall manganese production by 33% as Australia Manganese “executed its operational recovery plan and ramped up export” shipments.

It has issued a full-year guidance of 2 000 wet metric tons for its overall manganese productivity.

In South Africa, South32’s saleable manganese production decreased by 7%, reflecting underground development activity at Wessels while it has also scheduled maintenance works in the December 2025 quarter.

In Mozambique, South32 continues to engage the government, Hidroeléctrica de Cahora Bassa (HCB), and Eskom on securing sufficient and affordable electricity for Mozal Aluminium.

However, despite significant efforts, negotiations “have not progressed to provide confidence that Mozal Aluminium will secure a sufficient and affordable electricity supply” beyond March 2026.

“Without the required electricity supply, we expect that Mozal Aluminium will be placed on care and maintenance at the end of the current agreement,” said the company.

South32 CEO, Graham Kerr, said on Tuesday that the company had raised copper equivalent production at Sierra Gorda by 12% over the quarter.

“Our financial position remains strong as we continued our investment in growth at Hermosa, supported by $117 million in net distributions from our Sierra Gorda and manganese equity accounted investments during the quarter,” Kerr said.

“At Hermosa, we continued critical path shaft sinking for our Taylor zinc-lead-silver project, while the exploration decline for the Clark battery-grade manganese deposit remains on track to be completed in the December 2025 quarter.” 

The company is focused on maintaining operating momentum as it capitalises on strengthening market conditions in base metals.

For the period, net cash declined by $59m to $64m as South32 continued its “investment in growth at Hermosa, and experienced a temporary build in working capital” of $100m.

“The increase in working capital reflected higher finished goods inventories due to the timing of shipments, as well as payments accrued in the prior period,” it said.

At its Cannington operation, payable zinc equivalent production fell by 19%, a drop the company had anticipated as improved underground mining performance was offset by lower average metals grades.

The divestment of Cerro Matoso remains on track to be completed in the December 2025 quarter, further streamlining South32’s portfolio towards higher-margin businesses in commodities critical to the global energy transition.

Subsequent to the end of the period under review, the company paid a fully-franked ordinary dividend of $117m for the June 2025 half-year period.

BUSINESS REPORT