二次铝灰基多孔莫来石陶瓷制备研究

Study on the Preparation of Secondary Aluminium Ash Based Porous Mullite Ceramics

二次铝灰富含大量的铝元素,可在制备莫来石陶瓷材料中作为铝源。为综合利用二次铝灰,将水洗焙烧后的二次铝灰、活性硅粉、玉米淀粉和聚乙烯醇(PVA)结合剂采用固相烧结法制备多孔莫来石陶瓷,探讨Al_(2)O_(3)与SiO_(2)摩尔比、烧成温度、保温时间对试样性能的影响,并进行X射线衍射(XRD)与扫描电镜(SEM)分析。结果表明,在Al_(2)O_(3)与SiO_(2)摩尔比为1.8,温度为1200℃,保温时间为4 h的条件下,制备的多孔莫来石陶瓷体积密度为1.83 g/cm^(3),吸水率为18.05%,显气孔率为32.94%,抗压强度为18.46 MPa,且有柱状莫来石晶体生成,试样综合性能较优。

Secondary aluminium ash is rich in aluminium and can be used as an aluminium source in the preparation of mullite ceramic materials.In order to make comprehensive use of the secondary aluminium ash,the porous mullite ceramics were prepared by solid-phase sintering with the secondary aluminium ash after washing and roasting,activated silica powder,corn starch and PVA binding agent,the effects of the molar ratio of Al_(2)O_(3)to SiO_(2),sintering temperature,and holding time on the properties of the specimens were investigated and analysed by XRD and SEM.The results show that the porous mullite ceramics with bulk density of 1.83 g/cm3,water absorption of 18.05%,apparent porosity of 32.94%,compressive strength of 18.46 MPa are prepared,and columnar mullite crystals are produced under the conditions of Al_(2)O_(3)to SiO_(2)molar ratio of 1.8,temperature of 1200℃,and holding time of 4 h,the comprehensive performance of the sample is better.