Abstract
Industrial growth and the development of societies have led to increased waste generation and environmental degradation. Consequently, there have been attempts to search for alternative ways of reusing waste materials. Studies aimed at the insertion of these residues into ceramic materials are currently ongoing, partially because of the perceived potential for their suitability in this industrial branch. In this context, the present work aims to verify the potential use of the residue generated from a sludge that is an abundant byproduct of the processing of natural stone and that is difficult to discard. The study considers the use of this sludge as raw material in the development of a ceramic mass that is used in the manufacture of coatings, blocks, tiles, and bricks, among other applications. The residue from natural stone processing is then incorporated into the ceramic mass as a partial substitute for the less plastic clay of a standard mixture used in the ceramic industry located in the northwestern state of Esp??rito Santo (ES), Brazil. The characterization of the raw materials, clays, and residue was performed by X-ray diffraction, X-ray fluorescence, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, granulometric analysis, and plasticity index. Mixtures containing clays and residue were prepared, and from them cylindrical specimens were molded by the application of uniaxial pressure. Sintering of the specimens was conducted at temperatures similar to those used in the red ceramics industries, i.e., at 850?§C, 900?§C, and 950?§C. Physical tests were performed to determine the indices of water absorption, apparent porosity, apparent density, linear firing shrinkage, and compressive strength. The results obtained were analyzed to identify possible outliers, and the five most scattered results were eliminated. The experimental results indicate a potential for obtaining ceramic masses with technological properties that are comparable with those of masses employed for the production of the reference red ceramics.
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