刚玉基陶瓷膜的制备与性能研究

为了解原料粒径对刚玉基陶瓷膜形貌和性能的影响,分别以10 μm和20 μm的近等径刚玉为陶瓷膜原料,以硅溶胶为结合剂,六偏磷酸钠为分散剂,羧甲基纤维素为增稠剂,采用浸浆法在自制多孔SiC支撑体(平均孔径97.2 μm)表面涂覆刚玉基陶瓷膜,观察了膜的表面形貌、孔隙结构,并测试了膜的孔隙尺寸及分布、渗透性及阻力降。结果表明:当SiC支撑体孔径与刚玉颗粒的粒径之比<5时,制成的陶瓷膜表面平整;而当二者之比>10时,膜的表面出现明显凹坑。使用20 μm刚玉颗粒制备的刚玉陶瓷膜,其常温抗折强度为27.6 MPa,阻力降为426.6 Pa,气体渗透率为143.3 m 3·(m 2·h·kPa)^-1 ,具有较好的综合性能,可满足烟气净化的技术要求。

Preparation and properties of corundum-based ceramic membrane

This work aims at investigating the effect of raw material particle size on the morphology and properties of corundum-based ceramic membranes.Corundum-based ceramic membranes were prepared on surface of as-prepared porous SiC support (average pore size of 97.2 μm) by immersion,using near equal diameter corundum powders (10 μm and 20 μm) as raw materials,silica sol as the binder,sodium hexametaphosphate as the dispersant and carboxymethyl cellulose as the thickener.The surface morphology and pore structure of the membranes were observed.Pore size and distribution,permeability and pressure drop of the ceramic membranes were evaluated.The results reveal that when the ratio of the SiC support pore size to the corundum particle diameter is smaller than 5,the surface of the prepared membrane is smooth,while when the ratio is larger than 10,obvious pits can be observed on the surface of the membrane.The corundum ceramic membranes prepared with 20 μm corundum particles possess good comprehensive properties,such as flexural strength of 27.6 MPa,pressure drop of 426.6 Pa,gas permeability of 143.3 m 3·(m 2·h·kPa)^-1 ,which can meet the technical requirements of hot flue gas cleaning.