abstract
The present work aimed at studying the incorporation of wastes from natural rock cutting and polishing to produce roof tiles. The sintered products incorporating the sludge were targeted to have similar or even enhanced properties in comparison to those made of a standard reference paste industrially used to fabricate concurrent products available in the market. Firstly, the raw materials, including the sludge, were characterised by particle size distribution, density, X-ray diffraction (XRD), thermal properties and loss on ignition. Different formulations were prepared to evaluate the effects of each component on plasticity of pastes, drying and firing processes, and on the final properties of the tiles. Finally, the most promising formulations were selected and characterised for sintered density, water absorption, and flexural bending strength. The results obtained made it possible to conclude about the possibility of producing roof tiles incorporating 10% of granite wastes having excellent properties (water absorption <6%, lower pyroplastic deformation index, and bending strength values of about 14 MPa and 38 MPa for the green and sintered products, respectively). Therefore, the sludge derived from the granite cutting and polishing industries can be classified as a by-product suitable to replace natural non-plastic raw material in traditional ceramic formulations. This will contribute to preserve non-renewable natural resources, while it allows minimization of the negative environmental impact due to its disposal. (c) 2008 Elsevier Ltd. All rights reserved.
keywords
SLUDGES
subject category
Materials Science
authors
Torres, R; Fernandes, HR; Olhero, S; Ferreira, JMF
our authors
Hugo Alexandre Gonçalves da Rocha Fernandes
Junior Researcher
José Maria da Fonte Ferreira
Retired Professor
Paula Maria da Costa Torres
Assistant Researcher
Susana Maria Henriques Olhero
Assistant ProfessorGroups
G3 - Electrochemical Materials, Interfaces and Coatings
G5 - Biomimetic, Biological and Living Materials
acknowledgements
The financial support of CICECO is acknowledged. S.M. Olhero wishes to thank Foundation for Science and Technology (FCT) of Portugal for the financial support under the grant SFRH/BPD/27013/2006.