On the production of fired clay bricks from waste materials: A critical update

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.

Incorporation of wastes from granite rock cutting and polishing industries to produce roof tiles

The value of granite sludge wastes (GS) in cement-based mortar formulations was examined by assessing their potential as structural components and pigments. Full characterization of GS was accomplished by X-ray fluorescence (XRF), X-ray diffraction (XRD), laser diffraction and scanning electron microscopy. GS were found to be an effective filler or pozzolanic material for mortars. Also, GS were easily converted into a reddish pigment by calcination at low temperatures (700–900 °C) for a short time. UV–Vis–NIR spectra, colourimetric parameters and XRD analysis confirmed the presence of α-Fe2O3 in the pigment. Therefore, the preparation of coloured mortar with good compressive strength can be an attractive, environmentally friendly method of managing granite sludge wastes.

Use of granite sludge wastes for the production of coloured cement-based mortars

Utilization of muscovite granite waste in the manufacture of ceramic tiles

Reuse of sugarcane bagasse ash (SCBA) to produce ceramic materials.

This work has as its objective to evaluate the effect of granite powder waste incorporation in a red ceramic body. The granite waste came from an industry of stone sawing operations located in the municipal area of Santo Antonio de Padua, State of Rio de Janeiro, Brazil. Initially the granite sawing waste was characterized in terms of chemical composition, particles size distribution and X-ray diffraction. After that, clay mixtures with 0, 10, 20, 30 and 40 wt.% of granite waste were prepared. Red ceramic specimens were fabricated by extrusion and then fired in an industrial furnace at 970 °C. The specimens were also tested to determine the water absorption, linear shrinkage and three points bending flexural strength. Microstructural evaluation was carried out by scanning electron microscopy, X-ray diffraction and mercury porosimetry. The results indicate that granite waste presents favorable characteristics for addition into red ceramics due to facilities on the drying stages and decrease in porosity.

Incorporation of granite waste in red ceramics

This work has for objective to study the characteristics and technological properties of a typical roofing tile ceramic body from the county of Campos of Goytacazes-RJ with other three ceramic bodies of recognized technical quality, coming from States of Santa Catarina and Piaui and of Portugal. The ceramic bodies were submitted to analysis of X-ray diffraction, chemical composition, DTA/TGA, particle size distribution and plasticity. Samples were made by uniaxial pressure at 20 MPa for firing in temperatures varying from 825 to 1075 oC. The firing technological properties evaluated were: lineal shrinkage, water absorption and flexural strength (3 points). The results indicated that the ceramic body from Campos presents significant differences in the evaluated characteristics in comparison with the other ceramic bodies. Consequently, the ceramic body from Campos showed a different firing behavior, with higher values of water absorption, flexural strength and lineal shrinkage.

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Massas cerâmicas para telhas: características e comportamento de queima

Utilizacao de granito em massa ceramica para telhas

This work has for objective to study the characteristics and technological properties of a typical roofing tile ceramic body from thecounty of Campos of Goytacazes-RJ with other three ceramic bodies of recognized technical quality, coming from States of SantaCatarina and Piaui and of Portugal. The ceramic bodies were submitted to analysis of X-ray diffraction, chemical composition,DTA/TGA, particle size distribution and plasticity. Samples were made by uniaxial pressure at 20 MPa for firing in temperaturesvarying from 825 to 1075 q C. The firing technological properties evaluated were: lineal shrinkage, water absorption and flexuralstrength (3 points). The results indicated that the ceramic body from Campos presents significant differences in the evaluatedcharacteristics in comparison with the other ceramic bodies. Consequently, the ceramic body from Campos showed a differentfiring behavior, with higher values of water absorption, flexural strength and lineal shrinkage. Keywords

T. M. Soares

Papers

Incorporation of granite waste in red ceramics

Massas cerâmicas para telhas: características e comportamento de queima

Utilizacao de granito em massa ceramica para telhas

Massas cerâmicas para telhas: características e comportamento de queima (Ceramic bodies for roofing tiles: characteristics and firing behavior)