Description |
A novel ironmaking technology is being developed in a research group at the University of Utah headed by Professor H.Y. Sohn where large-scale bench reactor (LSBR) experimental investigations are conducted before launching the pilot-scale phase and eventual commercialization. The goal of the technology is to produce iron directly from magnetite concentrate, with lower carbon dioxide emissions and reduced energy consumption compared to the blast furnace technology. Product iron will be the feed for the steelmaking process, ultimately replacing the most widely used technology, the blast furnace. Computational fluid dynamics (CFD) modeling was performed to simulate the large-scale bench reactor and the industrial reactor for the novel technology using a program named ANSYS Fluent®17.1. CFD was performed to describe and analyze the performance of two different types of reactors for the flash ironmaking technology. User defined functions (UDF) was constructed to incorporate the chemical reduction of iron concentrate with reducing gas, previously determined in a drop-tube reactor at our research lab, into the continuity, momentum, and species transport equations. The first reactor is the large-scale bench reactor where a model was created using CFD to simulate the actual bench reactor operated in the University of Utah. The results of the simulation were validated by the experimental runs of the LSBR in the operating temperature range of 1150 - 1600 °C. The simulation results of the reduction degrees of concentrate particles and the composition of the off-gas from the reactor experimental iv data were found to have a satisfactory agreement. The developed model of the large-scale bench reactor was used to study the effect of the oxygen/natural gas ratio, the total input gas flow rate, and the concentrate powder feeding locations on the reduction degrees of the concentrate particles. The optimum operating conditions of the large-scale bench reactor required to achieve high reduction degrees of iron oxide concentrate were suggested. The second reactor is an industrial reactor to produce 0.3-1 million tons/yr of metallic iron using the flash ironmaking technology. Possible industrial reactors have been designed where higher than 90% metallization has been achieved. |