Corrosion Resistance Properties of Porous Alumina–Mullite Ceramic Membrane Supports

Abstract

Cost‐effective macroporous alumina–mullite membrane supports are fabricated by sintering coarse α‐alumina and colloidal silica, using cornstarch as the foaming agent at 1550 °C for 2 h in air atmosphere. To evaluate the corrosion resistance of such membrane supports, the corrosion behaviors of the supports before and after corroding in the H2SO4 and NaOH solutions (80 °C) are systematically investigated. Interestingly, with increasing Al2O3/SiO2 ratio, the support presents numerous alumina grains and little glass phases, resulting in excellent corrosion resistance especially in acidic media. Benefiting from the alumina grains and little glass phases among the grain boundaries, lower mass loss, less variations in pore size and porosity, high residual strength, and an almost unchanged gas flux are obtained for a higher Al2O3/SiO2 ratio support. The porous support, herein, is suitable for microfiltration membranes used in harsh environments.