Uso de materiais refratários recuperados em concretos para canais de corrida

Abstract

In order to achieve a sustainable production, in a sector where the demand for natural raw materials is very high worldwide, this project aimed to explore the feasibility of increasing the addition of recovered materials in castable refractory for application in main runners, as well as exploring the addition of a recovered material previously not used for this application, in order to reuse diversified refractory waste and save raw materials. The work focused on investigating the impact of increasing the addition of torpedo car chamotte (Al2O3-SiC-C) to 10%, as well as analyzing the addition of 10% of a new material: AZS chamotte (Al2O3-ZrO2-SiO2), to Al2O3-SiC- C based castable. This refractory is widely used in main runners due to its good properties of resistance to carbon oxidation, thermal shock, but mainly, resistance to pig iron and slag attack. Therefore, studies and packing adjustments were performed using the EMMA (Elkem Materials Mixture Analyzer) software, with the goal of obtain a higher efficiency in the replacement of the original raw materials of the castable, by the material to be reused, in order to obtain an adequate accommodation of the particles and, consequently, a packing as close as possible to the original castable. Thus, it was sought to obtain apparent porosity levels similar, or even lower than those of the original castable, in order to obtain adequate properties of mechanical strength, corrosion and oxidation resistance. Besides the packing study, used as an initial tool, an analysis of the castable raw materials was also performed, using data analysis in Python, aiming to optimize the flow properties of the material with the addition of the recovered materials. Thus, the influences caused in the properties of castable refractory, due to the addition of these recovered materials and the changes that were necessary during the packing adjustments were investigated. Even with the increased content of recovered materials, it was possible to obtain high fluidity, reduced apparent porosity, reduced carbono oxidation of the material, as well as wear to the attack of pig iron and slag close to those obtained with the original castable.