Microporous cordierite ceramics prepared from clay mineral mixtures containing vermiculite

Abstract

The porous cordierite ceramics were prepared using six clay mineral mixtures of talc, kaolinite and Mg-vermiculite, which has not been used for cordierite synthesis till now. The basic cordierite precursor was mixture consisted of talc, kaolinite and alumina. Other mixtures contained clay minerals and/or alumina with the stoichiometric MgO, SiO2 and Al2O3 ratio close to cordierite, 2MgO·2Al2O3·5SiO2. Ceramic samples contained cordierite enstatite and corundum. Pure cordierite formed from kaolinite nad vermiculite. Vermiculite contributed to the formation of large pores, alumina influenced struts architecture. The porosity of cordierite ceramics was in the range from 46% to 70%. Cordierites showed structural geometry close to the high-temperature hexagonal α-Mg cordierite.