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

Abstract Al 2 O 3 –Cr 2 O 3 refractories containing a minor amount of ZrO 2 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 Al 2 O 3 –Cr 2 O 3 refractory linings, both with and without corrosion, were analyzed. The results show that Al 2 O 3 –Cr 2 O 3 bricks were corroded by both molten slag and gas in the solid waste incinerator. Regarding the corrosion by molten slag, SiO 2 and CaO contained in the slag entered into the bricks along pores, which caused densification of the matrix and reaction of SiO 2 , CaO, and Al 2 O 3 to form CAS 2 ; FeO entered into the refractory and reacted with Al 2 O 3 and Cr 2 O 3 , forming the composite spinel FeO·Cr(Al) 2 O 3 . Moreover, the gas mixture of CO and Cl 2 also infiltrated into the Al 2 O 3 –Cr 2 O 3 brick and accelerated brick corrosion by reacting with ZrO 2 , Al 2 O 3, and Cr 2 O 3 one after another.