活性Al2 O3微粉种类对刚玉-尖晶石透气砖浇注料性能的影响

Effects of active alumina micropowder on properties of corundum-spinel castables for purging plugs

为探究活性Al_2O_3微粉对钢包用刚玉-尖晶石透气砖浇注料性能的影响,以质量分数分别为74%的板状刚玉、14.5%的镁铝尖晶石、8%的活性Al_2O_3微粉、2.5%的铝酸钙水泥和1%的减水剂制备了刚玉-尖晶石浇注料,研究了不同杂质含量和粒度分布的三种市售活性Al_2O_3微粉(分别为A、B、C)对该浇注料性能的影响。结果表明:三种活性Al_2O_3微粉中,加入粒度最小且Na_2O杂质较少的活性Al_2O_3微粉A的试样,在高温下的收缩量较小,显气孔率较低,在1 600℃时的高温抗折强度最大;显微结构分析显示,加入Al_2O_3微粉A的试样内部结构更加致密,孔洞相对较少。

In order to explore the effect of active alumina micropowder on properties of corundum-spinel castables for purging plugs, the corundum-spinel castables were prepared using 74% （by mass, the same hereinafter） of tabular alumina, 14.5% of magnesium-aluminate spinel,g% of active alumina mi- cropowder,2.5% of calcium aluminate cement and 1% of water reducer. Effects of three kinds of commer- cial active AI203 micropowder （A,B,and C） with different impurity contents and particle size distributions on the properties of the castables were studied. The results show that the specimens with active alumina micropowder A with the smallest particle size and less Na20 impurity have smaller shrinkage at high tem- peratures and lower apparent porosity,and the highest modulus of rupture at 1 600 ℃. The microstructure shows that the specimens with AI203 micropowder A are dense and have less pores.