不同类型高温窑炉用镁铬砖损毁机理分析

Destruction mechanism of magnesia-chrome bricks for different kinds of high-temperature furnace

作为优良的耐火材料,镁铬砖广泛应用于不同行业用高温窑炉,其损毁程度直接决定了高温窑炉的工作状况。不同类型高温窑炉用镁铬砖由于工作环境不同,其损毁机理存在差异。分析了RH炉、炼铜炉、水泥回转窑等典型高温窑炉用镁铬砖的损毁机理。结果表明,熔渣的化学侵蚀、温度急剧变化引起的裂纹和结构剥落是导致RH炉用镁铬砖损毁的主要原因;熔渣的化学熔蚀及熔体的渗透、炉内SO2气氛引起的结构疏松是导致炼铜炉用镁铬砖损毁的主要原因;水泥熟料液相的化学熔蚀、窑内还原性气氛引起的结构疏松及碱盐作用引起的裂纹是导致水泥窑用镁铬砖损毁的主要原因。损毁因素中,熔渣侵蚀及渗透是造成镁铬砖损坏的最关键性因素。

Magnesia-chrome bricks are widely used in high-temperature furnaces for their excellent performances,whose working conditions are determined by their damage.Due to different working environments,there are different destruction mechanisms of magnesia-chrome bricks used in high-temperature furnaces.The present study analyzes the destruction of magnesia-chrome bricks used in RH furnaces,copper production furnaces and cement kilns.The results show that erosion from molten slag and cracks caused by temperature change explain most of the brick destruction in RH furnaces;corrosion from molten slag,cracks caused by melts penetration,and structural osteoporosis caused by SO2 are the main destruction mechanism in copper production furnace,while corrosion caused by the liquid of cement clinker,structural osteoporosis caused by atmosphere,cracks produced by alkali salt result in the brick destruction in cement kiln.Among destructive forces,molten slag corrosion and penetration of magnesia-chrome bricks are the most critical factors.