JOHANNESBURG (miningweekly.com) – The sale of South Africa’s aluminium value chain assets to Alcoa Corporation of the US remains on track for completion in the June 2027 half-year, Johannesburg-, Sydney- and London-listed South32 reported in its September quarterly on Monday, October 19.

In the three months to September 30, aluminium production was largely unchanged as South Africa’s Hillside Aluminium in KwaZulu-Natal continued to test nameplate capacity with a quarterly output of 179 000 t. South32’s Brazil Aluminium is in ramp-up and as reported in March, South32’s Mozal Aluminium is on care and maintenance.

As a global producer of materials across the aluminium value chain – taking in mining, refining and producing bauxite, alumina, and aluminium – Alcoa of Pennsylvania was on July 1 described by South32 COO Africa Noel Pillay as being well positioned to operate South Africa’s Hillside Aluminium business into the future. This followed the signing by South32 of a binding conditional agreement to sell Hillside to the New York-listed Alcoa for up to $5.6-billion.

In addition to the Hillside aluminium smelter and South Africa’s idled Bayside smelter, Alcoa, headed by president and CEO William (Bill) F Oplinger, will also acquire South32’s interests in Boddington bauxite mine and the Worsley alumina refinery in Australia, as well as the Mineração Rio do Nortebauxite mine and the Alumar alumina refinery and aluminium smelter in Brazil.

Meanwhile, on the manganese front, South Africa’s manganese output for the quarter was 528 000 wet metric tonnes following South Africa Manganese lifting underground productivity at the Wessels mine in South Africa’s manganese-rich Kalahari basin, which is home to 80% of the world's manganese.

South32’s South Africa Manganese is made up of two manganese mines, the opencast Mamatwan mine, which started operating more than half a century ago, and the underground Wessels mine, which followed a few years later. Wessels has vertical and incline shafts and uses the mechanised bord-and-pillar mining method, while Mamatwan applies the terrace mining method. The two form part of Hotazel Manganese Mines.

New South32 CEO Matt Daley spoke of achieving key development milestones for the company’s copper and zinc growth projects.

Sierra Gorda, the opencast copper mine in the Antofagasta region of northern Chile, increased payable copper equivalent production by 11% on higher planned copper grades and paid a record quarterly distribution of $153-million. A fourth grinding line project at Sierra Gorda is expected to increase processing capacity by 25% and further increase the exposure to copper.

At Hermosa, in the Patagonia Mountains south-east of Tucson, Arizona, South32 continued construction of underground and surface infrastructure for the Taylor zinc/lead/silver project and completed the federal permitting process. Hermosa also has the zinc-/manganese/silver Clark oxide deposit, the copper/lead/zinc/silver Peake exploration target and the Flux prospect.

Hermosa provides the opportunity to leverage the underground mining and processing methods South32 has used at its Cannington operation in Queensland, Australia.

Net cash increased by $14-million to $297-million in the quarter and financial year 2027 production guidance remains unchanged, South32 stated in its release to Mining Weekly.