Effects of the Sintering Temperature on the Properties of Porous Ceramic Membrane Support Made of Fly Ash, Kaolin, and Claystone

Abstract

In this article, the influence of the sintering temperature on the properties of porous ceramic membrane support made of low-cost inorganic materials is reported. Fly ash was used as a dominant component since it presents cheap, abundant waste material and can be activated by alkalis to form porous structure with great mechanical resistance. Fly ash from coal combustion and additives, which consist of natural kaolin and claystone, were mixed with 5M NaOH solution to make a paste suitable for extrusion. Properties of created tubular porous supports, sintered at temperature ranging from 900 to 1100 °C, were characterized using a number of methods. Tubes sintered at 1000 °C were selected for microfiltration purpose. The morphology of the surface of these samples, studied by scanning emission microscopy (SEM) show homogeneous and crack free structure. Mercury porosimetry indicates uniform pore size distribution with average pore size value of 2.5 μm and pore volume of 38 % and show good mechanical resistance (7.7 MPa). These properties make fly ash-based ceramics suitable as membranes supports for microfiltration membranes technology.