Calix and Hydro have completed a comprehensive pilot-scale test campaign to produce smelter grade alumina using Calix’s electric calcination technology. The campaign forms part of an ongoing collaboration to develop electric calcination as a potential pathway to significantly reduce emissions from alumina refining.
Between October 2025 and April 2026, Calix’s fully electric and renewably powered multi-purpose pilot-scale calciner at the Calix Technology Centre in Bacchus Marsh, Victoria, was used to process aluminium tri-hydrate feed material from Hydro’s Alunorte refinery in Brazil. The test program was designed to evaluate the Calix technology’s capability to produce smelter-grade alumina, while also generating engineering data to support the design of a novel, scalable electric calciner for commercial alumina applications.
The campaign examined a wide range of operating conditions, including feed rate, reactor configuration, residence time and temperature profiling. In total, 68 test conditions were completed across the three-stage pilot program.
The results were highly encouraging. Calix’s smelter-grade alumina was successfully produced from the Alunorte feed material, meeting Hydro’s product specification requirements under the conditions tested. The campaign confirmed calcination temperature as the primary driver of conversion and product quality, with high-temperature single-pass operation providing a strong basis for future scale-up assessment. Reactor configuration was also shown to be an important lever for balancing product quality and energy efficiency.
Following review of the pilot test results, Calix and Hydro intend to establish the next phase of the collaboration, including a potential engineering study for a bespoke design that tailors the Calix technology for application in alumina calcination.
Calix General Manager, Sustainable Processing, Chris Ormston said, “This pilot campaign successfully demonstrated the production of smelter-grade alumina from Alunorte hydrate with electric heating. The results provide a strong technical basis to advance our zero emissions alumina technology alongside Hydro.”
