Decarbonising aluminium production is one of the most complex challenges facing the metals industry, requiring a multi-faceted approach across mining, refining, and smelting.
While recent policy announcements have focused on reducing emissions from the energy-intensive smelting process, experts stress the need for broader efforts to make the entire supply chain more sustainable.
“The three main stages of aluminium production are bauxite mining, refining bauxite into alumina, and smelting alumina into aluminium,” Alcoa Distinguished Professor Christopher Hutchinson from Monash University said.
“Smelting is the most energy-intensive step, as it relies on electrolysis to extract aluminium from alumina. This process requires an immense and constant supply of electricity, which must come from reliable and, in the future, low carbon sources. This challenge is truly gigantic.”
Beyond electricity, another major challenge in smelting is the carbon-intensive nature of current electrode technology.
“Today’s smelters use carbon electrodes, which react with oxygen during electrolysis, releasing more carbon dioxide than aluminium. Developing non-consumable electrodes is a promising solution, but we have yet to see commercial-scale implementation,” Hutchinson said
Alumina refining also poses significant decarbonisation challenges, particularly due to its reliance on high-temperature heat, which is predominantly supplied by fossil fuels.
“This heat will need to be provided from new, low carbon sources, but cost-effectiveness and scalability are critical,” Hutchinson said.
Additionally, the industry must address the environmental impact of red mud, a highly alkaline waste byproduct that currently has limited applications.
“With abundant bauxite reserves, existing industrial infrastructure, and vast renewable energy resources, we have a real opportunity to set a global benchmark. But unlocking this potential requires a coordinated national effort,” he said.
“Universities and organisations like CSIRO can play a key role in advancing green metal technologies. Establishing a National Institute for Green Metals, bringing together the best researchers from the universities and CSIRO with industry would accelerate collaboration and innovation—not just for aluminium, but for other critical metals like steel, copper, and lithium, that must similarly decarbonise their production.”