Development of green suspension ironmaking technology based on hydrogen reduction of iron oxide concentrate: rate measurements

A novel ironmaking technology is under development at the University of Utah. This technology produces iron directly from fine iron oxide concentrate by a gas–solid suspension reduction, utilising hydrogen as the main reducing agent for high reactivity, for the elimination of carbon dioxide release during ironmaking operations and also pursuing the direct use of concentrates to bypass the problematic pelletisation/sintering and cokemaking steps in the steel industry. This paper is mainly focused on the kinetic feasibility tests of the proposed process showing that the reduction rate was fast enough to obtain 90–99% reduction within 1–7 s at 1200–1500°C, depending on the amount of excess hydrogen supplied with the iron oxide. This indicates that the reduction rate of concentrate particles by hydrogen containing gases is sufficiently fast for a suspension reduction process and forms the most important basis for the new technology.