Abstract

REYES C, Fidel; INGALLS C, Alberto  and  BARRERA G, José Antonio. Análisis de la conducta iónica del sistema Hierro-Oxígeno. Rev. LatinAm. Metal. Mater. [online]. 2009, vol.29, n.1, pp.38-48. ISSN 0255-6952.

In this work two complementing ionic models are presented. A single anionic and cationic distribution of species results when the FeO-Fe₃O₄-Fe₂O₃ system is considered as an ionic melt or as an equilibrium molten salt. The first model was derived from the model based on the analysis of three molecular subsystems, namely FeO-Fe₂O₃, FeO-Fe₃O₄, and Fe₃O₄-Fe₂O₃. The ionic model for each of the subsystems was found to be ruled by the Temkin principles which led to the prediction of the  quasi ternary behavior of the Fe²⁺-Fe^M+-Fe³⁺ ions. The O^2- ions as well as the nonionic species, O_2(g) and Fe⁰, were involved in the model to satisfy the charge balance and stoichiometry. The second model is based on the occurrence of two simultaneous events: the FeO dissociation and the formation of complex species of Fe₂O₃ under critical molar proportions that lead to the equilibrium between Fe²⁺ and anionic complexes of the type Fe_nO_m^i-. The nature of these critical equilibria is analyzed under the light of molar, simple or superimposed ionic distribution when considered as the quasi ternary systems FeO-Fe₃O₄-Fe₂O₃ or Fe²⁺-Fe^M+-Fe³⁺.

Keywords : Iron-Oxygen System; Equilibrium; Molecular model; Ionic model.