Electrical characterisation of cordierite bodies containing Al-rich anodising sludge

Al-rich sludge produced from industrial anodising and surface treatment processes had been tested in the fabrication of cordierite-based materials, by using unidirectional dry pressing and extrusion as shaping techniques. Mixtures with commercial sand and magnesium-containing materials, like ball clay, and talc were prepared in order to achieve interesting final refractory and/or electrical insulating compositions. Microstructural changes upon sintering and crystalline phase evolution are detailed and their relationship with the electrical behaviour is now studied, by the use of impedance spectroscopy.