Use of zeolitic tuff in ceramic bodies

Abstract

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place" downloadurl="http://www.5iantlavalamp.com/"> Zeolitic tuffs, clays from the Istanbul area, rhyolitic-dasitic tuffs from Çanakkale-Tepeköy area and feldspars from Çine area are used in the preparation of ceramic bodies. Clinoptilolite, quartz, feldspar, biotite and volcanic glass basically form the mineralogical composition of the tuff. Total alkali content of Zeolitic tuff is between 4 and 5 per cent but iron content is less than 1 per cent. In the ceramic body, instead of Çanakkale tuffs, zeolitic tuffs are added with regular increment while the clays and other components stay in constant fractions. Fired colour parameters (<i style="">L</i>, <i style="">a</i>, <i style="">b</i>), dry and firing strength, water adsorption and firing shrinkage are measured. Thus the use of zeolitic tuffs was investigated in the fast fired ceramic bodies which are prepared by semi-dry pressing. Higher water absorption and lower shrinkage of Çanakkale-Tepeköy rich bodies are explained by their coarse quartz content. The grain size and distribution of quartz content and inversion-conversion change influence physical properties of fired bodies. As firing shrinkage increases, water absorption decreases regularly by addition of more zeolitic tuff to ceramic bodies. İn spite of lower Si content of Çanakkale-Tepeköy tuff, the water absorption property is influenced differently by the Si content when it originates from quartz of Çanakkale- Tepeköy or glassy phase of Demirci-Gördes zeolitic tuff. Therefore, chemical composition of the body is not the only factor to dictate the fired physical properties, such as water absorption and firing shrinkage. </smarttagtype></smarttagtype>