Opportunities of porous ceramics fabricated by gelcasting in mitigating environmental issues

Porous ceramics fabricated by gelcasting bring many unique capabilities in mitigating environmental issues, particularly waste recycling and neutralization of hazardous emissions. Potential opportunities for using gelcasting technique in setting mechanically foamed slurry can be described by adaptable designing and modification of the foamed slurry characteristics with a goal of preserving the environment. In this paper, we describe three directions of porous shaping routes through gelcasting in an attempt to mitigate environmental issues. Firstly, the fabrication of porous ceramics with inclusion of non-through holes and double-layered porous structure was described as an effective means of reducing pressure drop during filtration. Secondly, the non-toxic gel-former has been successfully applied to the gelling of waste loaded foamed slurry under ambient condition. The process has great benefit not only for the fabrication of lightweight ceramics with multifunction purposes, but also for the development of endless recycling system. Lastly, the pyrolysis of gelcast dried porous ceramics under oxygen-free atmosphere has provided a promising material as a filter having a heating function for oxidation of hazardous emissions. (c) 2008 Elsevier Ltd. All rights reserved.