Preparation of alumina disc ceramic membrane with enhanced abrasion resistance for dynamic membrane filtration

Abstract

Although disc ceramic membranes for dynamic filtration provide notable benefits in reducing membrane contamination, enhancing their resistance to erosive wear remains a challenging task. In this work, boehmite sol was employed as an effective additive to establish tightly connections between the membrane particles, and narrow the pore size of ceramic membrane with the increase of boehmite content. Alumina ceramic membranes with 15 wt% of boehmite sol and sintered at 1250 °C exhibited exceptional mechanical strength of 94 MPa, a porosity of 34 %, and an average pore size of 450 nm. Accelerated erosive wear tests were conducted by adjusting variables such as wear time, rotational speed and silica slurry concentration. It was observed that membranes prepared with 15 % boehmite sol exhibited a wear rate only 1/25th that of the without boehmite sol. Furthermore, the membrane displayed a consistent permeate flux of 1510 L m−2 h−1 bar−1 and a retention rate exceeding 99.5 % when filtering slurry containing 150 g/L of solid contents. After an extended duration of dynamic filtration, the flux and retention rate of the disc membrane exhibit a consistent and stable behavior. This disc ceramic membrane demonstrates promising potential for the filtration of suspensions with high solids content.