Preparation and Characterization of Ceramic Microfiltration Membrane using Red Mud as cost effective resource

Abstract

This work highlights the fabrication of ceramic microfiltration membranes using Red mud as the raw material. The raw material was pre-processed and paste casting method was used for fabrication. Two different membranes were successfully fabricated: membrane A and membrane B. Membrane A had a regular stoichiometric composition of red mud and binding agents whereas in case of membrane B, a significant percentage of kaolin was added to prop up the membrane matrix. After initial treatments, both the membranes were sintered at high temperatures e.g. 800 and 900oC respectively. Comprehensive material characterization techniques viz. scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), BET surface area analysis, Thermogravimetric analysis (TGA) and Mercury intrusion porosimetry were followed to ascertain the nature of the membrane fabrication and their inherent material properties. The membranes A and B being sintered at 900oC, reported an average pore size of 10 and 6µm respectively. These membranes were found well suited for oil-water emulsion and clarifying raw sugar cane juice studies. A maximum rejection of 53% was achieved with membrane B in oil-water emulsion studies. In sugar cane juice study as well, membrane B performed superior to its counterpart. The performance was reasonably well and membrane B reported 78% of turbidity and 28% of colour removal. In addition to that purity percentage was increased to 1.7 units. All the membranes were studied for their regeneration and reusability. The role of organic solvents was found to be important along with hot water wash. A detailed cost analysis was also performed and it was seen that the membranes fabricated were much cheaper than the similar products reported in literature.