Design of Novel Flash Ironmaking Reactors for Greatly Reduced Energy Consumption and CO2 Emissions

Abstract

The development of a novel ironmaking technology based on fine iron ore concentrate in a flash reactor is summarized. The design of potential industrial reactors for flash ironmaking based on the computational fluid dynamics technique is described. Overall, this simulation work has shown that the size of the reactor used in the novel flash ironmaking technology (FIT) can be quite reasonable vis-à-vis the blast furnaces. A flash reactor of 12 m diameter and 35 m height with a single burner operating at atmospheric pressure would produce 1.0 million tons of iron per year. The height can be further reduced by either using multiple burners, preheating the feed gas, or both. The computational fluid dynamics (CFD)-based design of potential industrial reactors for flash ironmaking pointed to a number of features that should be incorporated. The flow field should be designed in such a way that a larger portion of the reactor is used for the reduction reaction but at the same time excessive collision of particles with the wall must be avoided. Further, a large diameter-to-height ratio that still allows a high reduction degree should be used from the viewpoint of decreased heat loss. This may require the incorporation of multiple burners and solid feeding ports.

The Direct Reduction of Iron Ore with Hydrogen

“…Sohn et al [2] Developed a novel iron-making technology based on fine iron ore concentrate in a flash reactor. Optimization towards using multiple burners, preheating the feed gas, or both is examined.…”

A Kinetic Study on the Reduction of Single Magnetite Particle with Melting Products at High Temperature Based on Visual and Surface Analytical Techniques

“…To solve these issues, alternative and innovative ironmaking technologies have been developed, such as COREX, Midrex, FINEX, HIsarna, and flash ironmaking [4,5]. Among these, the novel flash ironmaking technology, which was conceived by Sohn et al from the University of Utah, has received much attention in recent years [6][7][8]. This technology can omit the complicated procedures, remove the energy consumption of the coking and sintering processes, and improve energy efficiency.…”

“…A schematic diagram of the flash ironmaking process is given in Figure 1, for which the detailed information can be found in Ref. [8]. The flash ironmaking equipment mainly includes a flash shaft, molten-iron bath, and uptake.…”

“…In the molten-iron bath, CH 4 , H 2 , O 2 , and coal are injected for further reduction of unreduced iron oxides or to be oxidized for the potential combination of the subsequent steelmaking process. H 2 , CO, H 2 O, and their mixtures are main gas reductants used in the alternative ironmaking technology and flash ironmaking technology [8][9][10], which can be produced from the gasification reaction with multiple solid fuels, such as coal or biomass [11,12]. Among these gases, H 2 is a highly reactive gas reductant for the reduction of iron ores.…”

“…Among these gases, H 2 is a highly reactive gas reductant for the reduction of iron ores. However, the disadvantage of this reduction is that it needs an extra external energy supply, which is commonly supplied from the combustion of CO, H 2 , and CH 4 with O 2 or the reduction of CO with Fe 2 O 3 [8,13,14]. When the iron ore is reduced by the gas mixtures of H 2 and CO, the reduction rate of iron ore with H 2 is higher than the value in CO [10].…”