South Africa’s largest aluminium smelter targets greener future with decarbonisation drive

Although aluminium from South Africa’s Hillside Aluminium in KwaZulu-Natal carries the value-dampening label of ‘high-carbon,’ South32, a globally diversified mining and metals company, gains a value boost from the ‘low-carbon’ premium status of its other two operations, Brazil Aluminium and Mozal Aluminium.

Hillside Aluminium & its decarbonisation efforts

Hillside Aluminium is labelled carbon-intensive due to its reliance on coal-fired electricity. However, there’s promising news that intensive efforts are underway to explore competitive decarbonisation solutions for Hillside, the largest aluminium smelter in the southern hemisphere and a key supplier of primary aluminium to South Africa’s value-adding secondary producers. In the six months to December, South32’s operational greenhouse gas emissions dropped by 9 per cent to 9.5 million tonnes of CO₂, primarily due to the sale of Illawarra Metallurgical Coal last year.

“We’ve been studying this technically and commercially for many years to see what’s possible for the business. More recently, that culminated in a request for information from the market, so we went to market to test what’s possible because our technical studies concluded that we could make Hillside work with solar PV and wind, obviously with backup investment. That process was actually over-subscribed, so lots of interest, and in isolation that was competitive. We are talking with Eskom, so there’s various options we’re looking at,” said South32 COO Noel Pillay.

Hillside Aluminium supports over 31,000 jobs and contributes nearly R10 billion to South Africa’s GDP, making its decarbonisation a significant opportunity. Addressing Hillside’s emissions — which account for 94 per cent of South32’s total Scope 2 emissions — could deliver substantial benefits, South32 CEO Graham Kerr highlighted in response to questions from Engineering News & Mining Weekly.

Strong start to FY25 –new projects and lots more

His remarks came as the company reported a strong start to FY25, driven by a portfolio transformation aligned with the global clean energy transition. South32’s climate strategy encompasses both operational and value chain decarbonisation, exploring nuclear and renewable energy solutions. The company is also working with Eskom to explore new renewable projects to create a streamlined, one-stop energy solution.

Ensuring a just energy transition for Hillside requires carefully planning the shift to low-carbon energy in collaboration with government and community stakeholders. At the same time, investments have been made in AP3XLE technology to reduce energy consumption.

“We’re trying to pull every lever that we can within what we can control and we’re halfway through converting all of our potcells to AP3XLE. But what we can control is very limited. The real issue here is the power source, which is what we’re working to find,” Pillay added.

Hillside’s FY25 production guidance stands at 720,000 tonnes — significantly exceeding the combined output of 130,000 tonnes from Brazil Aluminium and 350,000 tonnes from Mozal in Mozambique.  In the half-year, aluminium production rose by 5 per cent and copper by 16 per cent, allowing South32 to benefit from higher commodity prices. This drove a 44 per cent increase in underlying earnings to $1 billion. The company declared an interim ordinary dividend of $154 million, with an additional $171 million set to be returned to shareholders.

“We are focused on continuing our strong operating performance into the second half, unlocking value from our growth pipeline and continuing to reward shareholders as our financial performance improves. Our second climate change action plan, to be released in August, will detail our approach and the actions we are taking to address the risks and opportunities that climate change presents for our business,” added South32 CEO Graham Kerr.