Abstract: Microporous mullite aggregates were prepared from bauxite by dry pressing and firing at 1 700 ℃ for 3 h with corn starch,PMMA microspheres or rice husk powder as the pore-forming agent.The effects of the pore-forming agents and their addition (mass fraction of 0,5%,10%,15% and 20%,respectively) on the properties of microporous mullite aggregates were analyzed by XRD,SEM and Image-Pro Plus software.The results show that the comprehensive performance of the sample with 10 mass% rice husk powder is the best,the closed porosity is 5.6%,the bulk density is 2.63 g·cm^-3,the compressive strength is 148 MPa,the median pore size is 15.16 μm,and the thermal conductivity at 500 ℃ is 2.30 W·m^-1·K^-1.

Key words: microporous mullite, pore size distribution, phase composition, thermal conductivity

摘要： 以铝矾土矿为原料,以玉米淀粉、聚甲基丙烯酸甲酯微球或稻壳粉为造孔剂,采用干压成型后经1 700 ℃保温3 h制备了微孔莫来石骨料。用XRD、SEM借助Image-Pro Plus软件分析了造孔剂种类和添加量(质量分数分别为0、5%、10%、15%、20%)对微孔莫来石骨料性能的影响。结果表明:添加10%(w)稻壳粉的莫来石骨料的综合性能最佳,其闭气孔率为5.6%,体积密度为2.63 g·cm^-3,耐压强度为148 MPa,中值孔径为 15.16 μm,500 ℃时的热导率为2.30 W·m^-1·K^-1。

关键词: 微孔莫来石, 孔径分布, 物相组成, 热导率