Australian miner Rio Tinto has announced that it has signed a joint development agreement with Australian environmental technology company Calix to support construction of Calix’s green iron technology (Zesty™) demonstration plant in Western Australia, which could enable Pilbara iron ores to be used in lower-emissions steelmaking, complementing Rio Tinto’s longer-term BioIron™ research program.
Rio Tinto will invest more than A$35 million to help fund Calix’s Zesty™ green iron demonstration plant in Kwinana. The project also receives support from the Australian Renewable Energy Agency (ARENA).
Hydrogen-based reduction and electric heating technology
The Zesty™ process uses electric heating and hydrogen-based iron reduction, offering a pathway for processing lower-grade iron ores, which dominate Pilbara supply. If successful, the technology could broaden the range of ores suitable for hydrogen DRI and support the global shift toward fossil-free steel.
The demonstration plant will occupy the site originally earmarked for Rio Tinto’s BioIron™ research and pilot facility. Rio Tinto determined that the BioIron furnace design requires further development to minimize technical risks. Work on BioIron continues through partnerships with the University of Nottingham and Metso.
The Kwinana location provides access to utilities, port infrastructure and proximity to the NeoSmelt project, another ARENA-supported initiative that could process Zesty-produced DRI downstream.
Zesty™, ARENA grants and technology integration
Calix’s Zesty™ demonstration plant holds a conditional ARENA grant of A$44.9 million. Combined with Rio Tinto’s contribution, the funding will enable engineering, construction, commissioning and early-stage testing of the technology.
Under the agreement, Rio Tinto will provide:
- technical and engineering support to help reach final investment decision (FID),
- up to 10,000 mt of Pilbara ore for commissioning and early production,
- market introductions to potential downstream users of Zesty™-produced reduced iron.
Rio Tinto will also receive a global, perpetual, non-exclusive license to use or sub-license the Zesty™ technology, as well as rights to act as a non-exclusive global marketing agent.