Effects of Temperature, Refractory Composition and Mass Transfer Rate on Corrosion Rate of Al₂O₃–SiO₂ System Bricks into CaO–SiO₂–Al₂O₃–MgO Slag

Abstract

The corrosion rate of Al₂O₃–SiO₂ system bricks, which are practical fired bricks, into CaO–SiO₂–Al₂O₃–MgO slag was investigated, and the effects of temperature, refractory composition and mass transfer rate in slag on the corrosion rate of the bricks were discussed. As a result, the corrosion rate decreased as the alumina content in the brick increased. The corrosion rate increased with increasing temperature. The corrosion rate decreased with decreasing rotational speed, that is, mass transfer of Al₂O₃ and SiO₂ in the slag phase. Corrosion proceeded at the rate of 1.3 mm/min even when the rotational speed of the refractory sample was 0 rpm. Based on an analysis of the experimental results from the viewpoint of transport phenomena, under the conditions of this study, it is estimated that the reaction proceeds under a condition in which natural convection is rate-controlling for mass transfer when the rotational speed is lower than 44 rpm, in a transition region, that is, a mixed condition of natural convection and forced convection, at speeds of 44–133 rpm, and under a condition in which forced convection is rate-controlling when the rotational speed is over 133 rpm.