%0 Journal Article
%T Gres porcel¨¢nico esmaltado producido por v¨ªa seca: materias primas fundentes
%A Melchiades
%A F. G.
%A dos Santos
%A L. R.
%A Nastri
%A S.
%A Boschi
%A A. O.
%J Bolet¨ªn de la Sociedad Espa£¿ola de Cer¨¢mica y Vidrio
%D 2012
%I Sociedad Espa?ola de Cer¨¢mica y Vidrio
%R 10.3989/cyv.192012
%X Fluxing agents are particularly important in porcelain tile compositions because this type of ceramic tile requires high volumes of vitreous phases during firing to eliminate open porosity. The volume and viscosity of the vitreous phases formed during firing control the densification process and thus determine the firing temperature and pyroplastic deformation. The fluxing agents commonly employed in porcelain tile compositions are feldspars, phyllites (used in Brazil) and nephelines. These raw materials are water-insoluble, which makes them particularly suitable for compositions of traditional porcelain tile produced by the wet route. However, a large group of water-soluble raw materials also have a good potential to act as fluxing agents and could be used in dry route processes. In this context, the purpose of this work was to determine the fluxing potential of water-soluble or partially water-soluble raw materials in a porcelain tile composition. The effectiveness of several borates, i.e., colemanite, ulexite, hydroboracite, as well as sodium carbonate, was tested in a comparative study. The results of this study indicate that small additions of these fluxing agents suffice to greatly reduce the firing temperature without causing high pyroplastic deformation of the bodies. The best results were obtained in compositions containing hydroboracite. This finding is especially relevant for the creation of alternative compositions of porcelain tiles produced by the dry route. Dry route processing is currently the focus of a great deal of interest due to environmental and economic issues. Los agentes fundentes tienen una especial importancia en las composiciones de gres porcel¨¢nico, ya que este tipo de baldosa cer¨¢mica requiere altos vol¨²menes de fases v¨ªtreas durante el proceso de cocci¨®n para eliminar la porosidad abierta. El volumen y la viscosidad de las fases v¨ªtreas que se forman durante la cocci¨®n controlan el proceso de densificaci¨®n y, por consiguiente, determinan la temperatura de cocci¨®n y la deformaci¨®n piropl¨¢stica. Los agentes fundentes que se usan habitualmente en las composiciones de gres porcel¨¢nico son: feldespatos, filitas (usadas en Brasil) y nefelinas. Estas materias primas no son solubles al agua, lo que las hace particularmente adecuadas para las composiciones de gres porcel¨¢nico tradicional producido por v¨ªa h¨²meda. Sin embargo, existe un gran grupo de materias primas solubles que tambi¨¦n tienen un gran potencial como fundentes y que podr¨ªan utilizarse en los procesos de v¨ªa seca. En este contexto, el objetivo de este trabajo ha sido d
%K porcelain tiles
%K fluxing
%K borates
%K dry route
%K vitrification
%K piezas de gres porcel¨¢nico
%K agente fundente
%K boratos
%K v¨ªa seca
%K vitrificaci¨®n
%U http://ceramicayvidrio.revistas.csic.es/index.php/ceramicayvidrio/article/view/1120/1155