FORMATION OF IRON-ORE SINTER MINERALOGY AND MICROSTRUCTURE: TOWARDS A COMPREHENSIVE CONCEPTUAL MODEL OF THE FLAME FRONT

摘要

Here we present a model of the formation mechanism of sinter mineralogy and microstructure in highly fluxed sinter (CaO/SiO_2 -2.8-3.8), obtained by detailed investigation of quenched flame front and final sinter product samples. Contrary to the suggestion of several other studies, the observations here indicate only negligible solid-solid reaction and formation of low temperature Ca-ferrites prior to melting. Flash melting of adhering fines layers in the presence of solid carbon is the norm. Moreover, the formation of typical binding matrix dominated by acicular SFCA-I does not pass through a lower temperature, oxidised precursor stage, and instead can form by progressive oxidation of a reduced precursor stage comprising Fe~(2+)-dominated melt + magnetite-rimmed ore-relicts via peritectic reactions during oxidation and cooling.