ZHOU Jianer ,ZHANG Xiaozhen, YANG Hao, WANG Ting
(University Key Laboratory for Inorganic Membrane in Jiangxi Province, Jingdezhen Ceramic Institute, Jingdezhen 333001)
Abstract: Natural minerals mullite and kaolin were used as main raw materials for the preparation of mullite composite microfiltration (MF) membrane. The prepared mullite -based support and MF membrane were characterized in terms of structrue and properties. The mullite-based support was prepared from the mixture of 90wt% mullite powder (d50＝9.85μm)and 10wt% kaolin by dry pressing. The prepared support shows a mean pore size of 2.1 μm, porosity of 46.9%, pure water flux of 9.1 m3·m-2·h-1·bar-1 and bending strength of 23.1MPa with sintering at 1250℃ for 3h. Mullite MF layer was prepared on the porous support by the combination of dip -coating method and solid state sintering. The suspension, with 10wt% mullite (d50＝1.14μm), 7% PVA and 0.8% PAA and pH =11, exhibits good dispersity and stability, and was used for the preparation of mullite MF membrane on the mullite support. The mullite MF layer shows a mean pore size of 0.24μm and thickness of 18μm when sintered at 1200℃ for 2h . The as-prepared mullite composite MF membrane shows a pure water flux of 0.83 m3·m-2·h-1·bar-1, and can be used in the MF separation process.
Keywords: Microfiltration membrane; Mullite；Chracterization; Permeate flux; Mean pore size