不同Al_2O_3含量的镁铝尖晶石抗钢包渣侵蚀性研究

Corrosion resistance of magnesium aluminate spinels with different Al_2O_3 contents to ladle slag

分别以四种不同Al2O3含量的镁铝尖晶石粉S67、S70、S78、S90为原料,纸浆废液为结合剂,混匀后压制成型,经烘干和1 600℃3 h热处理后,进行1 600℃保温3 h的抗钢包渣侵蚀试验,并对侵蚀后的四种尖晶石试样进行显微结构分析,以比较其抗钢包渣侵蚀性能的差异。结果表明:随着尖晶石原料中Al2O3含量的增加,抗渣侵蚀性能逐渐减弱,抗渣渗透性逐渐增强,但Al2O3质量分数增加到约90%(即S90)时其抗渗透反而有所减弱。SEM分析显示:在尖晶石受渣侵蚀过程中生成的MgO-FeOx固溶体和(Mg,Mn,Fe)(Fe,Al)2O4复合尖晶石,能起到抑制渣侵蚀和渗透的作用;而渗透层中游离的Al2O3与渣中CaO反应生成高熔点的CA6和CA2相,并以网络结构贯穿于尖晶石中间,有利于阻止渣的进一步渗透。综合考虑抗侵蚀性能和渗透性能认为,尖晶石原料S78抵抗钢包渣侵蚀能力较强。

The specimens were prepared using magnesium aluminate spinel with different AI203 contents （S67,S70, S78, and S90, respectively） as starting materials, and sulphite lye as binder, mixing well, and pressing shaping. After drying and heating at 1 600 ℃ for 3 h,the specimens were used for ladle slag cor- rosion test at 1600 ℃ for 3 h. The corroded specimens were analyzed by SEM and their corrosion resist- ances to ladle slag were compared. The results show that..with the AI203 content increasing in the spinel materials,the spinel shows worse corrosion resistance, but better penetration resistance except that the penetration resistance of S90 gets worse. The SEM analysis shows the formed MgO-FeOx solid solution and the complex spinel （Mg ,Mn ,Fe）（ Fe,AD2O4 ） in the corrosion process can depress the corrosion and penetration of slag ;in the penetration layer,free Al2O3 will react with CaO from the slag forming high melt- ing point phases CA2 and CA6 interweaving with the spinel,which is favorable to prevent the further slag penetration. The S78 spinel has better resistance to ladle slag.