Abstract

In batches of pyroconsolidated pellets, produced at the Siderúrgica Del Orinoco SIDOR, C.A. From direct iron ore from the train and ore stored in the yards, similar deviations were detected in terms of Compressive Strength (C.R.), Abrasion Index (A.I.) and increase in the fraction <1/4" that are associated with degradation mechanisms. In order to explain this behavior, representative samples were selected from both batches of pellets, which were analyzed using optical microscopy and scanning electron microscopy techniques coupled with an energy-dispersive microanalyzer, complemented by analysis by X-ray Diffraction. , with the interest being the identification of the compounds or phases formed in pyroconsolidation. It is determined from these analyzes that both pellet samples are microstructurally similar, characterized by presenting sintered iron particles with molten silicate unions and untransformed gangue fractions. The presence of particles made up of magnesium-rich phases related to possible MF-Magnetite compounds (Magnesium ferrite dissolved in magnetite) with a faceted appearance, with a darker tone than the grain matrix, stands out. The origin of this last phase is attributed to operating conditions of high pyroconsolidation temperatures added to high MgO/SiO2 ratios in the pellet, which can negatively impact the resistance and favor its degradation. The XRD analysis confirms the presence of complex silicates associated with calcium - magnesium in a smaller proportion that is also related to slag enriched in magnesium.