On-line version ISSN 1678-4553
MORENO, M. M. T.; BARTOLOMEU, D. and LIMA, R. H. C.. Analysis of the firing behavior of clays and formulations for ceramic tiles. Cerâmica [online]. 2009, vol.55, n.335, pp. 286-295. ISSN 1678-4553. http://dx.doi.org/10.1590/S0366-69132009000300008.
The use of red fired clays for the production of ceramic tiles has become important due to the technological progress and the improvement of raw material quality. In this processing, dry milling is used and the maximum firing temperatures are larger than 1000 ºC with the occurrence of sintering reactions through liquid phase. In this work, the behavior of red clays and their mixtures to obtain the best sintering conditions was studied. Individual types of clay were analyzed using the following parameters: wt.% in the composition, maximum firing temperature and absorption of water of the individual raw materials. Test specimens were fired in laboratory with temperature varying between 800 and 1100 ºC. After characterization of the individual properties, binary and ternary combinations of clays were analyzed using the same conditions of the individual ones. The results obtained allowed us to elaborate a proposal of how to prepare these types of mixtures based on the raw material. Because mixtures show variations on their response that are mainly dependent on the particle size distribution and fluxing compounds, it is necessary to perform corrections in the composition of the mixture to reach the desired properties. Using the proposed methodology, it is possible to orientate the changes in the composition in order to reach the desired result.
Keywords : red clays; ceramic tiles; firing behavior.