Abstract
A novel H2 based single stage reduction ironmaking technology named ZESTY (Zero Emissions Steel TechnologY) has been developed by carrying out pilot plant testing at a facility in Bacchus Marsh near Melbourne. The process uses counter current flow of hydrogen and iron ore fines (less than 500 micron) in an electrically heated tubular reactor; residence time of particles are estimated to be 40 to 80s in the reactor depends on the particle size and gas flowrate. Initial pilot plant trials in 2023 established the general characteristics of the reactor and in 2024, an extensive testing campaign in a fully electric pilot reactor for a range of Australian-sourced hematite/goethite and magnetite. Characterization of the products demonstrated that hematite goethite ores can achieve metallization levels above 95% operating below 1050 °C, the best results being achieved for particles less than 200 micron with highly porous structures. Particle size, mineralogy, ratio of hydrogen to reducible oxide, porosity and reactor temperature play a crucial role in determining the level of metallization achieved. A thermogravimetric technique using flow through fine samples on a wire mesh to study the kinetics of the process has been established to study the kientics of the process. A multi-zone thermodynamics and kinetic model have been developed to provide a basis by which to understand how key parameters affect reactor performance. Further fundamental work is underway to inform the development of a 30,000 tpa demonstration plant.