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.

Permeability and corrosion resistance of the porous alumina doped by Y2O3 with monodispersed PMMA as pore former

“…Then it can be undoubtedly concluded that the corrosion resistance to sulfuric acid of the porous alumina fabri-cated in this work is superior to that reported in references. For corrosion resistance to alkali, the mass loss induced by the corrosion is lower than those in [16], [17], [27], [28], and [29]. The welling time employed in the references was shorter than that in this work.…”

“…For samples fired at the same temperature, the mass loss induced by the corrosion was increased obviously with the PMMA addition increased from 0 to 20 wt.% due to increased porosity. 27 Figure 9C,D illustrates the comparison between the mass loss caused by corrosion of the porous alumina prepared in this study and those reported. 16,17,[27][28][29] For corrosion resistance tests of the porous alumina to acid or alkali, various acid and alkali with different concentrations were used.…”

“…Figure 9C,D illustrates the comparison between the mass loss caused by corrosion of the porous alumina prepared in this study and those reported 16,17,27–29 . For corrosion resistance tests of the porous alumina to acid or alkali, various acid and alkali with different concentrations were used.…”

“…Thus, higher mass loss can be observed for samples with CA as raw powders. For samples fired at the same temperature, the mass loss induced by the corrosion was increased obviously with the PMMA addition increased from 0 to 20 wt.% due to increased porosity 27 …”

Core-Shell Structured Carbon@Al2O3 Membrane with Enhanced Acid Resistance for Acid Solution Treatment

“…However, given that defects usually accumulate at oxide grain boundaries, hydrogen ions enter the vacant sites of the lattice and combine with oxygen negative ions, which often causes the dissociation of metal ions [32,33]. As an amphoteric metal oxide, alumina may be susceptible to acid corrosion, which mainly occurs with inter-crystalline phases and additive-produced glass phases [32,34]. For example, Ma et al found that the corrosion resistance was improved as the proportion of Al 2 O 3 /SiO 2 increased, especially in an acidic environment [34].…”