Abstract: To actively respond to the dual-carbon policy and reduce industrial energy consumption,it is urgent to develop lightweight and high-strength refractories.Lightweight mullite castables were prepared using microporous mullite,mullite fine powder,alumina micropowder,alumina bubbles and silica micropowder as the raw materials and cement as the binder.The effects of the alumina bubbles addition (0,3%,6% and 9%,by mass,respectively) on the properties of the mullite castables were studied.The results show that alumina bubbles can increase the porosity of the samples and promote the formation of mullite from alumina micropowder and silica micropowder,which solves the problem that the mechanical properties of the samples decrease greatly due to the increase of the apparent porosity.With the increase of the alumina bubbles addition,the apparent porosity of the samples increases significantly,the bulk density decreases,the thermal conductivity decreases significantly,the thermal shock resistance improves,and the strength decreases slightly.When the alumina bubbles addition is 9%,the apparent porosity of the sample heat treated at 1 400 ℃ is high,the bulk density and thermal conductivity are low,but the cold strength is still high.

Key words: mullite castables, alumina bubbles, mechanical properties, thermal shock resistance

摘要： 为积极响应双碳政策,减少工业能源消耗,亟需开发轻质高强耐火材料。以微孔莫来石、莫来石细粉、氧化铝微粉、氧化铝空心球和二氧化硅微粉为原料,水泥为结合剂,制备了轻质莫来石质浇注料,研究了氧化铝空心球加入量(加入质量分数分别为0、3%、6%和9%)对莫来石浇注料性能的影响。结果表明:氧化铝空心球能提高试样的气孔率,并促进氧化铝微粉和二氧化硅微粉生成莫来石相,解决了试样因显气孔率增大而力学性能降低幅度较大的问题。随着氧化铝空心球加入量的增加,试样的显气孔率明显增加,体积密度降低,热导率显著下降,抗热震性提高,强度降低较少。当氧化铝空心球添加量为9%(w)时,试样经1 400 ℃热处理后的显气孔率较高,体积密度和热导率较低,但常温强度仍然较高。

关键词: 莫来石浇注料, 氧化铝空心球, 力学性能, 抗热震性能