Elaboration and chemical corrosion resistance of tubular macro-porous cordierite ceramic membrane supports

摘要

Tubular macro-porous supports for ceramic micro-filtration membranes were prepared by extrusion followed by sintering from low cost commercial grade cordierite powder. The effects of sintering temperature on the micro-structure, fracture strength, LTEC (linear thermal expansion coefficient), pore size distribution and permeation flux were studied. Our results indicate that the optimized sintering temperature was in the vicinity of 1380 ℃. The fabricated cordierite supports showed an average pore diameter of 8.66 μm, open porosity of 36.20%, nitrogen gas flux of 1.45 × 10~4 m~3 m~2 h~(-1) and LTEC of 4.34 × 10~(-6) ℃~(-1) (between 25 and 1000℃). To verify the practicability in the strong corrosive environment, the chemical resistance tests were carried out in the sodium hydroxide and sulfuric acid solutions under the boiling condition, respectively. Compared with the as-used alumina supports, the cordierite supports exhibited better thermal alkali resistance but poorer acid resistance according to the mass loss results. In addition, the corroded cordierite supports were characterized by fracture strength, open porosity and pore size distribution. The fabricated macro-porous supports are expected to have potential applications in the pre-treatment of strong alkali media and dust-containing hot gas.