DECARBONISING RIO TINTO'S AUSTRALIAN ALUMINA REFINERIES

Alumina refining is the second step in the three-stage process to produce aluminium metal. In Gladstone, Queensland, Rio Tinto owns and operates the Yarwun alumina refinery and owns 80% of Queensland Alumina Limited (QAL) in a non-managed joint venture. These assets contribute approximately 15% of Rio Tinto Group’s total emissions and are some of the hardest to abate within our portfolio.
Decarbonisation solutions for the alumina refining industry are technically challenging and, in some cases, do not exist at the required scale. The alumina refining process requires large-scale energy to generate process heat and, in Australia, the industry’s success has been underpinned by access to low-cost fossil fuels, predominately coal and gas.
Decarbonising alumina refining requires new, large-scale renewable electricity to generate the zero-emissions process heat currently provided by fossil fuels, and significant upgrades to the electrical infrastructure supplying refineries. This substantial capital investment in technology development and deployment is challenging for what are relatively low-margin assets.
To abate emissions from these refineries, Rio Tinto is investigating:
1. Reducing the amount of energy required through process changes and improvements.
2. Improving energy efficiency and use by recovering low-grade waste steam and electrifying existing processes.
3. Switching to lower carbon fuels, including hydrogen to generate heat.