Solid State Science and Technology, Vol. 17, No 1 (2009) 89-103

ISSN 0128-7389




Zarina Abdul Wahid1, Rafindde Ramli1, Andanastuti Muchtar2 and

Abd Wahab Mohammad2


1Ceramics Technology Group, SIRIM Berhad, 1, Persiaran Dato’ Menteri, P.O. Box 7035, 40911 Shah Alam, Malaysia

2Faculty of Engineering,Universiti Kebangsaan Malaysia,

43600 UKM Bangi, Selangor, Malaysia



The usage of ceramic filters in the separation industries has become increasingly important especially in the wastewater treatment, food and beverages industries. This is because ceramics are inert materials, have high mechanical strength and can withstand high temperatures and corrosive environment [1-4]. Fused-alpha-alumina has been used very widely as ceramic filter elements or as supports for ceramic membrane filters. This is due to the high flexural strength, high porosity and low pore size characteristics exhibited by this material for ceramic filters. Furthermore, its particle structure which is elongated helps created interlocking structure which enhances the ceramic filters capability. The effects of the particle size and sintering temperatures on the performance of the alumina filters were investigated in this paper. Three particle sizes of alpha-alumina with different average sizes were studied: F500 (20 μm), F600 (10 μm) and F 2000 (1 μm). The apha-alumina powders were mixed with bentonite clay, CMC and water and extruded into tubular form with certain dimensions. The tubes were sintered at 1100° to 1500°C following a fixed temperature programme. The alumina tubes were then characterised for thermal, mechanical and physical properties. The optimum sintering temperature for each size was determined. The findings of this study showed that generally higher sintering temperatures and lower particle sizes reduce porosity and increase flexural strength. These properties however, have to be balanced in order to achieve good ceramic filters. Overall, F500 was found to have excellent properties for ceramic membrane filters at 1350°C sintering temperature with high porosity (40-50%), high flexural strength (60-70 Mpa), reasonable pore size (5 μm) and good permeability capability.



[1]. P. Bolduan and M. Latz (2000). Ceramic membranes and their applications in food and beverage processing. Filtration and Separation 4, 36-38.

[2]. E. Coberth (2003). Membrane Separation. SRI Consulting Business Intelligence.


[3]. R. Sondhi, R. Bhave and G. Jung (2003). Applications and benefits of ceramic membranes. Membrane Technology 11, 5-8.

[4]. R.W. Baker, (2000). Membrane Technology and Applications. California: McGraw-Hill.

[5]. A.J. Burggraaf and L. Cot (1996). Fundamentals of Inorganic Membrane Science and Technology, Amsterdam: Elsevier.

[6]. S. Rakib, M. Sghyar, M. Rafiq, A. Larbot and L.Cot (2001). New porous ceramics for tangential filtration. Separation and Purification Technology 25,385-390.

[7]. S-H. Lee, K-C. Chung, M-C. Shin, J-I. Dong, H-S. Lee and K.H. Auh (2002). Preparation of ceramic membrane and application to the crossflow microfiltration of soluble waste oil. Materials Letters 52, 266-271.

[8]. C.D. Jones, M. Fidalgo, M.R. Wiesner and A.R. Barron (2001). Alumina ultrafiltration membranes derived from carboxylate-aluminoxane nanoparticles. Journal of Membrane Science 193,175-184.

[9]. L. Chu and M.A. Anderson (1996). Microporous silica membranes deposited on porous supports by filtration. Journal of Membrane Science 110, 141-149.

[10]. A. Larbot, A. Julbe, C.Guizard and L. Cot (1989). Silica membranes by sol-gel process. Journal of Membrane Science 44, 289-303.

[11]. S. Rakib, M. Sghyar, M.Rafiq, A. Larbot and L.Cot (2001). New porous ceramics for tangential filtration. Separation and Purification Technology 25, 385-390.

[12]. S. Khemakhem, R. Ben Amar, R. Ben Hassen, A.Larbot, M. Medhioub, A. Ben Salah and L. Cot (2004). New Ceramic Membranes for Tangential Waste-Water Filtration. Desalination 167,19-22.

[13]. Z. Abdul Wahid, R. Ramli, A. Muchtar and A.W. Mohammad (2005). Influence of sintering temperature on the characteristics of α-alumina filtration tubes. In Proceeding of the conference Scientific and Analytical Methods in Manufacturing SAMM 2005

[14]. Z. Abdul Wahid, R. Ramli, A. Muchtar, A. and A.W. Mohammad (2005). The development of a-alumina filtration tube using the extrusion technique. In Proceedings of the conference Advanced Processes and Systems in Manufacturing (APSIM 2005) ISBN 938-2446-19-8, pages 113-116, Bangi, Malaysia, May 2005.

[15]. R.A.Terpstra (1995). Ceramic processing, London: Chapman & Hall.

[16]. E. Jakobs and W.J. Koros (1997).Ceramic membrane characterization via bubble point technique. Journal of Membrane Science 124, 149-159.

[17]. A.L. Ahmad, S. Ismail and S. Bhatia (2005). Membrane treatment for palm oil mill effluent: effect of transmembrane pressure and crossflow velocity. Desalination 179, 245-255.


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