The effects of nucleation and growth on the reduction of Fe2O3 to Fe3O4

  title={The effects of nucleation and growth on the reduction of Fe2O3 to Fe3O4},
  author={Peter C. Hayes and Paul Grieveson},
  journal={Metallurgical Transactions B},
The kinetics of reduction of hematite powder to magnetite in CO-CO2 gas mixtures at temperatures between 500 and 663 °C have been measured. The reactions are described in terms of a simple nucleation and growth model. The chemical reaction rate constants for the reduction of hematite to magnetite are obtained and the nucleation frequencies of magnetite on hematite are calculated for a range of temperatures and oxygen partial pressures. A possible technique for the improvement of the… 
Microstructural changes on the reduction of hematite to maanetite
The microstructures resulting from the reduction of hematite to magnetite have been examined for a wide range of temperatures and gas conditions. A transition in product morphology from plate or lath
The influence of specific impurities on the nucleation and growth of magnetite during reduction of artificially prepared hematite
The influence of traces of specifically added impurity oxides on the reduction behavior of hematite to magnetite has been investigated. Oxides of Al, Ca, Mg, or Si have a direct influence on the
Microstructural Changes and Kinetics of Reduction of Hematite to Magnetite in CO/CO2 Gas Atmospheres
The microstructures of porous magnetite formed on gaseous reduction of dense hematite have been examined using high-resolution scanning electron microscopy. It has been shown that cellular pores are
Influence of reduction conditions on the expansion and microtexture of sintered hematite compacts during the transition to magnetite
Permeability in the blast furnace shaft is adversely affected by low-temperature reduction degradation of sinters. The fundamental cause of this is the expansion of the iron oxide phase resulting
The decomposition of wustite under mixed chemical reaction/mass transport limitations
Numerical solutions have been obtained for the mixed chemical reaction/diffusion limited planar decomposition of a wustite slab prior to iron metal nucleation. The results of the analysis are
The effect of emergent dislocations on the kinetics of decomposition of solid surfaces under conditions of chemical reaction control
Using a simplified model of an oxide surface containing emergent dislocations, it has been shown that the overall chemical reaction rate constant for the reduction of an iron oxide reaction surface
Reducibility of potassium-promoted iron oxide under hydrogen conditions
There is economic incentive to operate the ethylbenzene dehydrogenation reaction at low steam/ethylbenzene ratios. To develop catalysts capable of performing under these conditions, it is necessary


Interfacial reaction kinetics in the decarburization of liquid iron by carbon dioxide
The kinetics of decarburization of liquid iron have been studied between 1160 and 1600°C under conditions where mass transport of reactants is not rate determining. Studies with continuously
The effect of absorbed oxygen on the kinetics of chemical reactions on metal surfaces
The effects of adsorbed impurities on the kinetics of reactions on metal surfaces are discussed, in particular the reactions of water vapor and carbon dioxide with iron surfaces are analyzed. The
High voltage microscopy of the reduction of hematite to magnetite
The microstructural changes associated with the formation of magnetite in hematite have been studied in specimens which have been partially reduced outside the microscope, thinned until electron
Kinetics of Phase Change. I General Theory
The theory of the kinetics of phase change is developed with the experimentally supported assumptions that the new phase is nucleated by germ nuclei which already exist in the old phase, and whose
Bedeutung der Keimbildung bei der Reduktion von Wüstit*
Die Ausgangssubstanz Wüstit definierter Fehlordnung wurde durch Reduktion von Fe203-Pulver mit einem OO/CC^-Gemisch bei Temperaturen zwischen 700 und 900 ° C erzeugt. Durchverschieden langes Tempern