The Preparation of Microfiltration Ceramic Membrane from Alumina

Abstract

This research described the preparation of tubular microfiltration ceramic membrane from alumina. The results showed that a suitable composition of raw materials for body forming by extrusion was alumina powder, sodium carboxymethylcellulose, zinc stearate and water in the ratio of 7 2.5, 2, 0.5 and 2 5 wt%, respectively. The symmetric membrane with considerable strength was obtained when sintered at 1600 ^oC for 1 hour. This membrane has pore sizes in the range of 0.5-2 µm (average 1 µm), 44% porosity and filtration resistance 1.30x10⁹ m^-l.

Investigation on the parameters affecting the membrane properties indicated that the amount of water in raw material was a very important factor for body forming. The appropriate amount of water was at 25 wt%. It was also found that the sintering time and temperature had no significant affect on membrane pore size. The porosity, however, decreased from 53%  to 44% when sintering temperature was increased  from 1400 to 1600 ^oC and the decrease was from 44 88% to 44 66% when sintering time was increased  from 1 to 5 hours. Moreover, the pore size distribution was observed to be narrower with increasing sintering temperature and time.