Effect of holding time on properties of macroporous support sintered at low temperature

Tubular macroporous supports were fabricated using alumina (α-Al₂O₃) and titanium dioxide (TiO₂) as starting materials via a plastic extrusion method. The effect of the holding time on the linear shrinkage, bulk density, pore structure, permeability and three-point bending strength of the supports at a sintering temperature of 1400°C was investigated. The formation mechanism of the promising macroporous support was also preliminarily analyzed. The results show that the solid state reaction between Al₂O₃ and TiO₂ at 1400°C favors greatly to obtain a support with integrated properties of high permeability and sufficient mechanical properties. The properties of the support sintered at 1400°C for 2 h are the pure water flux of 45 m³/(m²·h) at 0.1 MPa, the average pore size of 6.8 μm and the three-point bending strength of 32.7 MPa, respectively. There is little variation of bending strength of the supports immersed in 1% (in mass) NaOH (90°C for 720 h), indicating that the support can be used as a microfiltration membrane support due to its excellent corrosion-resistant property in hot NaOH.