Reduction process of carbon-containing high-silicon ore pellets in H2-H2O-N2 and CO-CO2-N2 atmospheres
The study investigated the reaction behavior of carbon composite agglomerates in H2-H2O-N2 and CO-CO2-N2 atmospheres to meet the new requirements for energy conservation and emission reduction in blast furnace ironmaking.The composition,mineral phases,and microstructure of the composite agglomerates were analyzed using chemical analysis,X-ray diffraction(XRD),and scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS).The reaction kinetics model for carbon composite agglomerates was established by analyzing their reduction behavior in CO-CO2-N2 and H2-H2O-N2 atmospheres.The reduction degree and carbon gasification rate of the composite agglomerates were higher in the H2-H2O-N2 atmosphere than in the CO-CO2-N2 atmosphere at temperatures of 1 073,1 173,1 273 and 1 373 K.A comparative analysis of the reaction process of carbon-containing agglomerates was conducted at 1 273 K in both atmospheres.After 20 min of reaction in the H2-H2O-N2 atmosphere,the FeO phase disappeared from the agglomerates based on the XRD spectra.In contrast,in the CO-CO2-N2 atmosphere,the FeO phase remained in the agglomerates,indicating better reducibility of the composite agglomerates in the H2-H2O-N2 atmosphere.Electron microscopy images were also compared for both atmospheres,and it was observed that a significant aggregation of metallic iron occurred at the edges after 25 min of reaction.A reaction kinetics model was developed for the composite agglomerates,considering the conservation of mass for both gas and solid components,as well as the mass transfer between the agglomerates and the gas phase.The model was found to fit well with the experimental results,demonstrating its reliability.
NETL
NSTL
万方数据
