Mining company South32 has agreed to sell its Worsley alumina operations in Western Australia to Alcoa in a transaction valued at approximately US$5.6 billion (A$8.1 billion). The deal, announced in late July 2026, includes South32’s bauxite, alumina, and aluminium assets and represents a significant consolidation of Alcoa’s presence in Western Australia.

Alcoa, headquartered in New York, is positioned to expand its bauxite mining activities in the state to supply its Pinjarra and Wagerup refineries. However, the company faces regulatory challenges related to environmental approvals, particularly concerning expansions into forested areas. Alcoa also recently closed its Kwinana refinery in 2024, a facility that employed around 800 workers.

As part of the agreement, Alcoa will assume approximately US$1.2 billion (A$1.7 billion) in rehabilitation obligations tied to the South32 assets. Alcoa’s CEO, Bill Oplinger, described the acquisition as a strategic fit, emphasizing that the assets align with the company's global portfolio and operational capabilities.

Beyond the Western Australian operations, the sale includes South32’s 100% ownership of the Hillside Aluminium plant in South Africa, as well as minority stakes in several Brazilian assets: 33% in the MRN bauxite mine, 36% in the Brazil Alumina refinery, and 40% in the Brazil Aluminium smelter. South32’s suspended operation in Mozambique remains under consideration for divestment but was not included in this transaction.

The sale comes amid mounting pressure from environmental groups targeting bauxite miners in Western Australia, reflecting broader concerns about the environmental impacts of mining and industrial operations in the region. South32 had previously highlighted job risks, citing that about 1,700 positions were at risk following the Western Australian government's 2024 decision to cease regulating greenhouse gas emissions—a move that South32 appeared to benefit from.

The deal is subject to approvals by South32 shareholders, the Australian Foreign Investment Review Board, the Australian Competition and Consumer Commission, the South African Reserve Bank, and other regulatory bodies. Both companies have indicated the transaction will proceed once these conditions are met.

This acquisition strengthens Alcoa’s position as a major aluminium producer in Australia and internationally, while allowing South32 to streamline its portfolio amid evolving market and environmental conditions.