利用高铝粉煤灰制备多孔陶瓷工艺研究

Preparation of Porous Ceramics Using High-Aluminum Fly Ash

以脱硅高铝粉煤灰为主要原料、石墨为造孔剂制备多孔陶瓷。利用X射线衍射仪和扫描电子显微镜分析多孔陶瓷的物相组成和微观结构,万能试验机测试抗弯强度,阿基米德排水法测定显气孔率和体积密度,采用渗透通量评价其过滤性能。研究结果表明:随着烧结温度的升高,多孔陶瓷的莫来石含量、体积密度和抗弯强度逐步增大,刚玉和石英的含量、显气孔率、吸水率和对水的渗透通量逐渐减小。随着石墨添加量的增加,多孔陶瓷的物相组成变化不大,体积密度和抗弯强度逐步降低,显气孔率、吸水率和对水的渗透通量相应增加。添加30wt%石墨、1450℃烧结的多孔陶瓷,抗弯强度为9 MPa,显气孔率为48. 28%,大气压下,对水的渗透通量达到714 L·m^(-2)·h^(-1)。

Porous ceramics were prepared by using desiliconized high aluminum fly ash as main raw material and graphite as pore former. Phase composition and microstructure of porous ceramics were analyzed by X-ray diffractometer and scanning electron microscope. The universal testing machine was used to test the flexural strength. The Archimedes method was used to determine the porosity and bulk density. The permeation flux was used to evaluate the filtration performance. The results show that the mullite content, bulk density and flexural strength of porous ceramics increase gradually with the increase of sintering temperature, and the content of corundum and quartz, apparent porosity, water absorption and permeability to water decreased gradually. With the increase of graphite addition amount, the phase composition of porous ceramics changes little, the bulk density and flexural strength decrease gradually, and the apparent porosity, water absorption as well as the permeation flux to water increase accordingly. When adding 30wt% graphite and sintered at 1450 ℃, the porous ceramics achieved the flexural strength of 9 MPa, apparent porosity of 48.28%, At atmospheric pressure, the permeation flux to water reaches 714 L· m ^-2 · h ^-1 .