高温过滤支撑体用SiC基多孔陶瓷的制备与表征

通过以平均粒径300 μm的SiC为骨架材料,特定配比的高岭土、长石和二氧化硅的混合物为粘结剂,制备了可用于高温过滤膜管支撑体的SiC基多孔陶瓷.将粘结剂在1300 ℃烧结并保温1 h,X射线衍射(XRD)分析表明粘结剂中主要为石英相和玻璃相.多孔陶瓷的气孔率随着粘结剂含量从3%增加到15%(质量分数,下同)先升高后降低,其抗弯强度随着粘结剂含量的增加而增加.在粘结剂含量为10%时,多孔陶瓷的气孔率和抗弯强度都取得了较高的值,分别是34.3%和36.6 MPa.压汞法测得其平均孔径为24 μm,孔径分布较窄.用X射线能谱(EDS)测得不同SiC颗粒粘结处的粘结剂的元素组成,并与粘结剂设计组成对比,结果显示粘结剂各组分在多孔陶瓷中分布较均匀.利用扫描电子显微镜(SEM)观察了多孔陶瓷试样条断面的形貌.研究表明此多孔陶瓷可用作高温煤气过滤管的支撑体材料.

Fabrication and Characterization of SiC-Based Porous Ceramic Used for High Temperature Filtration Supporter

Silicon carbide (SiC) powders and a mixture of kaoline, feldspar and silica were adopted as the starting materials for the fabrication of SiC porous ceramic used for high temperature filtration supporter. The average particle diameter of SiC powders used as a skeletal material was 300 μm. The mixture of kaolin, feldspar and silica, which was used as a binder, was sintered at 1300 ℃ for 1 h. The X-ray diffraction (XRD) result indicates that the phase composition of the sintered mixture was mainly composed of quartz and glass. With increasing of the content of binder from 3 wt% to 15 wt%, the flexural strength correspondingly increases, and the porosity of the porous ceramic firstly increases and then decreases. The porous ceramic has 34.3% porosity and 36.6 MPa flexural strength at 10 wt% binder content, with a narrow pore size distribution and an average pore size of 24 μm. The composition of the binder between SiC particles was characterized by energy dispersive spectroscopy (EDS) with the results that the determined composition is close to the designed composition.