关键词: 水泥窑, 铝硅系耐火砖, 碱侵蚀

Abstract: The alkali corrosion resistance of commercial SiC-mullite brick 1 680,SiC-mullite brick 1 550,spalling resistant high alumina brick JA,and low alumina mullite brick M55 was tested by the crucible method.The phase composition and the microstructure of the bricks after corrosion and the alkali corrosion behavior were discussed.The results show that:(1)the alkali corrosion resistance of the SiC-mullite bricks and low alumina mullite bricks is better,while that of the spalling resistant high alumina brick is worse;(2)the silicon carbide in the SiC-mullite bricks oxidizes at high temperatures,forming a dense layer on the surface of the bricks,which can effectively inhibit the infiltration of K element,so the material has excellent alkali corrosion resistance;the spalling resistant high alumina brick,due to the low grade raw materials,has high porosity and the deepest alkali penetration depth;a large amount of kaliophylite forms,leading to big cracks,so the material has poor alkali resistance;(3)the low alumina mullite brick has low porosity,whose raw materials are mullite homogenous materials and andalusite with a dense structure;a certain amount of high silicon amorphous phase can react with K element producing high viscosity glass phases to block pores,so the brick has better alkali corrosion resistance.

Key words: cement kiln, alumina-silica refractory bricks, alkali corrosion