Por: Carlos Maurício Fontes Vieira (universidade estadual do norte fluminense darcy ribeiro ), Geovana Carla Girondi Delaqua (universidade estadual do norte fluminense darcy ribeiro), Carlos Alberto de Oliveira Guimarães (UNIVERSIDADE ESTADUAL DO NORTE FLUMINENSE DARCY RIBEIRO)
Resumo:
Campos dos Goytacazes in the north region of the State of Rio de Janeiro, Brazil, has become a large producer of red ceramic wall bricks. The industries are now interested in the fabrication of products with greater intrinsic value such as extruded floor tiles. However, the refractory behavior of the local clays poses some serious difficulties. Therefore, the objective of this paper was to evaluate the characteristics, firing behavior, technological properties and the microstructure of a typical industrial extruded floor tile body from Campos dos Goytacazes, Brazil. The firing behavior was studied by thermal analysis (DTA/TG) while the microstructural characteristics were evaluated by mercury porosimetry, nitrogen adsorption/desorption, scanning electron microscopy and X-ray diffraction. Technological properties such as water absorption, linear shrinkage and flexural strength of specimens fired from 900 to 1200oC were also evaluated. The results showed that the industrial ceramic body presents a high porosity, which does not attend floor tile specifications even at a firing temperature of 1200oC. This is due to the predominance of kaolinite and relatively high weight loss during firing, associated with a significant amount of clay mineral and the occurrence of aluminum hydroxide decomposition