Development of tailored ceramic microstructures using recycled marble processing residue as pore-former

Recycling of marble processing residue is significant since marble processing constitutes an important industrial sector. Therefore, the sustainable management and the valorisation, in an economically profitable manner, of this industrial by-product should be considered. In this work, the potential use of marble residue as pore-former into clayey mixtures for the production of lightweight, porous and thermal insulating ceramics is investigated. Four samples consisting of clayey ceramic body incorporating up to 50 wt.% fine marble residue powder were produced. The final ceramic products were produced upon firing (sintering) at 950oC. Porosity and thermal conductivity measurements were carried out in order to assess the thermal insulating behavior of the produced sintered ceramics. The porosity of the sintered ceramics increases substantially by increasing the marble residue admixture loading. This, in turn, leads to a decrease in thermal conductivity. Consequently, the marble residue can be successfully employed as pore-forming agent, in order to improve the insulating behavior of the ceramic materials.