Waste-to-resource preparation of a porous ceramic membrane support featuring elongated mullite whiskers with enhanced porosity and permeance

Different from traditional particle packing structure, a porous structure of ceramic membrane support was fabricated, featuring elongated mullite whiskers with enhanced porosity, permeance and sufficient mechanical strength. The effect of additives (MoO₃ and AlF₃) and sintering procedure on open porosity, mechanical properties, pore size distribution, micro-structure, phase structure, and permeance of the membrane supports was characterized in detail. The introduction of MoO₃ and AlF₃ promoted formation of a porous whisker-interlocked structure, which effectively improved open porosity and permeance. A mullite membrane support containing 5wt.% MoO₃ and 4wt.% AlF₃ exhibited an open porosity as high as 48.6±0.5%, a mechanical strength of 81.2±3.2MPa at 1200°C, and the value of permeance was higher than the membrane without any additives. Such enhancements in porosity and permeance, with sufficient mechanical strength, were a result of tortuosity decrease due to a porous structure of interlocked mullite whiskers.