Porous sintered ceramic materials having mullite as its primary phase and a method for producing them are disclosed. The method comprises preparing a plasticizable raw material mixture comprised, by weight, of 75 to 99% pre-reacted mullite powder, and 1.0 to 25% of a water-swelling clay, adding an organic binder system to the mixture and mixing the mixture to form an extrudable mixture, and extruding the mixture to form a substrate of the desired configuration. The green body is dried and fired for a time and at temperature sufficient to form a sintered mullite structure having a narrow through-pore size distribution comprised of pores exhibiting an average intrusion-pore size of between about 2-15 µm, and a total intrusion porosity, as measured by Hg intrusion method, of at least 30%. Inclusion of an amount of alumina or an alumina-yielding precursor in the method results in the formation of a sintered mullite structure exhibiting an acid/base exposure strength loss of less than about 20%.
展开▼
