硅微粉对Al_2O_3-SiC-C质铁沟料的性能影响

Effect of Microsilica on the Properties of Al_2O_3-SiC-C Castables for Iron Trough

本文以棕刚玉、碳化硅粉、氧化铝微粉、纯铝酸钙水泥(Secar71)等原料制备了Al_2O_3-SiC-C(ASC)质铁沟浇注料,探讨了低硅微粉加入量(质量分数分别为0、0.5%、1%、1.5%)对铁沟浇注料性能的影响。研究结果表明:在110℃烘干24 h和在1450℃煅烧保温3 h后,随着硅微粉加入量的增加,铁沟料加水量逐渐减小,显气孔率呈现先减小后增大的趋势,体积密度的变化趋势与显气孔率的正好相反,常温抗折强度及耐压强度呈现逐渐增强的趋势,加入1.5%硅微粉的试样线膨胀系数比1%试样的大。综合分析ASC铁沟浇注料在高炉使用过程中各方面的性能要求,在现有颗粒级配工艺下,低硅微粉较为合适的含量为1.0%。

Al_2O_3-SiC-C castable for iron trough were prepared by using brown corundum,silicon carbide powder,aluminium oxide micropowder,and calcium aluminate cement（Secar71）.The influence of microsilica addition（Mass fractions were 0,0.5%,1%,1.5%） on properties of the castable were investigated.The results show that the Iron Trough＇s water addition decreases gradually with the increase of microsilica addition.After drying at 110 ℃ for 24 h and firing at 1450 ℃ for 3 h,Al_2O_3-SiC-C castable samples＇ apparent porosity decreases at first and then increases afterwards,but the samples＇ bulk density changes reversely comparing with that of apparent porosity.The samples＇ flexural strength and compressive strength show a trend of gradual enhancement and the linear expansion coefficient of the ASC castable sample with 1.5% microsilica is larger than that with 1% microsilica.Comprehensive analysis,according to the performance requirements of ASC castables for iron trough used in blast furnace process,the optimum microsilica content is 1.0%.