A comparative study on the slag resistance of dense corundum-spinel refractory and lightweight corundum-spinel refractory with density gradient

Abstract Lightweight corundum-spinel refractory with a density gradient structure from exterior to interior was fabricated. Slag resistance of lightweight and dense corundum-spinel refractory is investigated by X-ray diffraction, scanning electron microscopy, energy dispersive analysis, mercury intrusion porosimetry and Factsage. The results show that lightweight corundum-spinel refractory with high apparent porosity exhibits comparable slag resistance to dense corundum-spinel refractory, especially with superior slag penetration resistance. The dense exterior with small pore size in the lightweight corundum-spinel refractory can effectively hinder slag penetration. Corrosion product phases (C2S, CA2, CA6, and C2M2A14) with high melting point and inconsistent melting temperature, most of Fe and Mn elements in steel slag solubilizing in spinel, especially strip CA6 around corundum aggregate, prevent the refractory from further slag penetration and corrosion.