South32 alumina output increase set for FY2026–27 on Worsley expansion

South32

South32 alumina output increase is planned as the miner lifts FY2026–27 production to 5.3mn t. The South32 alumina output increase reflects new, higher-quality bauxite areas approved in Western Australia. As a result, the South32 alumina output increase contrasts with a decline in primary aluminium smelting.

Worsley Alumina lifts throughput as new bauxite areas come online

South32 will raise alumina production to 5.3mn t in FY2026–27. It guided 5.1mn t for FY2024–25 and FY2025–26. The step-up relies on Worsley Alumina’s mine life extension and better bauxite quality. Moreover, the firm will invest $90mn in 2025–26 to support the expansion. Australian federal approval in February unlocked new mining areas. Therefore, Worsley’s feed blend should improve, stabilizing refinery yields and costs. Higher-grade bauxite typically reduces caustic consumption and energy intensity. Consequently, unit costs and carbon intensity can trend lower as ore quality rises.

Aluminium smelting retreats; Chinese bauxite reliance rises

South32’s aluminium output will fall to 885,000t in FY2026–27. It was 1.2mn t last year and 1.1mn t expected in FY2025–26. The Mozal smelter will produce 240,000t by March 2026, then enter care and maintenance. Power constraints drive the pause, curbing ex-China metal supply. However, South32 sees long-term aluminium growth outside China. It expects non-Chinese producers to deliver 90pc of new capacity over the next decade. Meanwhile, China’s refineries will lean more on imported bauxite. South32 projects imports will support 79pc of Chinese alumina output by 2029. That compares with 71pc in 2024, underscoring rising seaborne dependency. As a result, bauxite trade flows and refinery siting remain strategic for decarbonized metals.

The Metalnomist Commentary

The alumina uplift at Worsley offsets smelting headwinds and preserves South32’s oxide leverage. Watch unit costs, energy inputs and caustic usage as higher-grade bauxite feeds the circuit. Policy and power reliability will dictate how quickly mothballed smelting capacity can return.