Utilization of sepiolite in the synthesis of porous cordierite ceramics

Porous cordierite ceramics were prepared using sepiolite source of MgO and SiO2 and alumina as starting materials by simple dry-pressing/sintering. The sepiolite/alumina green bodies were sintered at 1100-1350 degrees C for 2 h. The characterization was focused on thermal analysis, phase evolution, sintering behavior, thermal expansion and micro-structural changes using DSC/TG, XRD, dilatometry and SEM. alpha-Cordierite was formed above 1200 degrees C. the amount of which increased steadily with the sintering temperature. Increasing sintering temperature also improved the densification (especially above1000 degrees C), and decreased the thermal expansion (especially above 1200 degrees C). Porous cordierite with a bimodal pore size distribution (1.4-1.9 mu m and 10 mu m) was prepared with cornstarch as pore-former. (C) 2011 Elsevier B.V. All rights reserved.