SiO2微粉加入量对铝镁质捣打料性能的影响

摘要

To further improve performances of the alumina magnesia dry ramming mix,alumina magnesia ramming mix were prepared by using fused white corundum (5-3,3-1,≤1 and ≤0.074 mm) and ≤ 0.088 mm magnesia as raw materials,and SiO2 micro-powder and α-Al2O3 micro-powder as additives.The effects of SiO2 micro-powder additions (the mass percent was 1％,2％,3％,4％ and 5％,respectively) on the linear change rate,apparent porosity,bulk density,cold crushing strength and phase composition of the fired specimens were investigated.The results show that increasing the addition of SiO2 micro-powder,the linear change rate of alumina magnesia ramming mix decreases gradually from (+ 1.41％) to (-1.51％),apparent porosity decreases and bulk density erratically increases,in addition,cold compressive strength basically shows a trend of increase.The main phases are α-Al2O3,Al2MgO4 and trace of αSiO2 in the specimen added by 2％ SiO2 micro-powder.Comprehensively considering various properties,2％ SiO2 addition is appropriate for the alumina magnesia ramming mix.%为了进一步提高现有铝镁质干式捣打料的性能,以粒度5～3、3～1、≤1和≤0.074 mm的电熔白刚玉及粒度≤0.088 mm的电熔镁砂细粉为主要原料,以分析纯SiO2微粉和α-Al2 O3微粉为添加剂,制备了铝镁质捣打料.研究了SiO2微粉加入量(质量分数分别为1％、2％、3％、4％、5％)对铝镁质捣打料的烧后线变化率,烧后试样的显气孔率、体积密度、常温耐压强度、物相组成等的影响.结果显示:随着SiO2微粉加入量的增多,铝镁质捣打料的烧后线变化率逐渐减小,从膨胀1.41％变化至收缩1.51％;烧后试样的显气孔率逐渐减小,体积密度不规律地增大,常温耐压强度基本上呈增大趋势;SiO2微粉加入量为2％(ω)的烧后试样的物相主要为α-Al2O3和Al2MgO4以及微量的α-SiO2.综合考虑各项性能,铝镁质捣打料中SiO2微粉加入量以2％(ω)为宜.