Corrosion of Al2O3-Cr2O3 refractory lining for high-temperature solid waste incinerator

摘要

Al2O3-Cr2O3 refractories containing a minor amount of ZrO2 usually have excellent heat stability and corrosion resistance. However, a short service life is observed in high-temperature solid waste incinerators. Therefore, the phase compositions and microstructure of the Al2O3-Cr2O3 refractory linings, both with and without corrosion, were analyzed. The results show that Al2O3-Cr2O3 bricks were corroded by both molten slag and gas in the solid waste incinerator. Regarding the corrosion by molten slag, SiO2 and CaO contained in the slag entered into the bricks along pores, which caused densification of the matrix and reaction of SiO2, CaO, and Al2O3 to form CAS(2); FeO entered into the refractory and reacted with Al2O3 and Cr2O3, forming the composite spinel FeO Cr(Al)(2)O-3. Moreover, the gas mixture of CO and Cl-2 also infiltrated into the Al2O3-Cr2O3 brick and accelerated brick corrosion by reacting with ZrO2, Al2O3, and Cr2O3 one after another. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.