关键词: 危废焚烧回转窑, Na₂O, 卤素, 刚玉-莫来石砖, 侵蚀

Abstract: The corundum-mullite bricks used in the combustion zone of a hazardous waste incineration rotary kiln were sampled,and the microstructure and composition of the sampled residual bricks were analyzed by XRD,SEM,and EDS.The corrosion mechanism of corundum mullite bricks under the corrosion of halogen-containing and high sodium salt content slag in hazardous waste incineration rotary kilns was investigated.The results demonstrate that the sodium salt,potassium salt,Br,Cl,and other elements in the slag possess strong corrosion and penetration abilities,generating low melting point and low density substances such as NaCl,KBr,and sodalite in the matrix,which decreases the hot performance of the brick in the combustion zone and accelerates the corrosion and wear of the brick.On the other hand,they cause irreversible volume expansion of the brick body,leading to spalling during the operation of the rotary kiln.

Key words: hazardous waste incineration rotary kiln, Na₂O, halogen, corundum-mullite brick, corrosion