Review and data evaluation for high-temperature reduction of iron oxide particles in suspension

Abstract

High-temperature reduction processes of iron oxide particles suspension are promising in carbon emission abatement. Recently, researchers have contributed abundant knowledge of the reaction mechanism and kinetics of iron oxide particles above 1473 K, while there was very limited information 10 years ago. Although the understanding of the high-temperature reduction of iron oxide particles is still not comprehensive, a brief review of the academic reports is helpful for the future work on this topic. The high-temperature reduction of iron oxide suspension is characterized by having: rapid reaction, obvious thermal decomposition and melting process. Evaluation of the kinetic data shows that the reduction process of single particles is not rate-determined by the diffusion process at the studied temperatures. The reaction rate constant is within 10 −2 -10 s −1 in these studies. Furthermore, comparing previous studies in iron oxide reduction field, the phase transformation and effect of gangue minerals to the reduction of iron oxide particles above 1473 K requires more input and research. ARTICLE HISTORY

Induction Heating in Nanoparticle Impregnated Zeolite

“…According to the observed mass losses (see Table 2 ), these processes can be assigned to the transformation of γ-Fe 2 O 3 to Fe 3 O 4 and to the reduction of Fe 3 O 4 to metallic Fe, respectively. It is worth noting the low temperature at which Fe 3 O 4 reduces to metallic Fe which usually occurs at higher temperatures (T > 900 °C) [ 45 , 46 ]. This is because the nanoparticles have a large specific surface exposed to H 2 gas which favors the reduction.…”

Reduction Mechanism of Fine Hematite Ore Particles in Suspension

“…Hematite ore was partially reduced to suboxides in the specified atmospheres. Accorading to the thermodynamic analysis, [14,15] these suboxides contained magnetite and liquid oxide, and the liquid oxide turned to wu¨stite in the quenching process. The partially reduced ore particles in resin were polished and investigated with an optical microscope.…”

Evaluation of devolatilization behaviour of different carbonaceous materials under rapid heating for the novel HIsarna ironmaking process

“…Several reactions take place simultaneously during rapid heating of the carbonaceous materials, including break-up of chemical bonds, vaporization, and condensation [50]. Previous studies have indicated that the post combustion ratio (PCR) value of reducing gas has an important influence on the pre-reduction degree in the HIsarna's cyclone, which is greatly influenced by carbonaceous materials devolatilization [17], [51]. The total yield of gas products evolved from the carbon sources (per 1 gram of sample) during rapid heating to the temperatures of 1500 °C is plotted in Figure 9.…”