Last modified: 2018-01-01
Abstract
To investigate the effects of talc on floor tiles glaze as opacifier
Murtaza Khan*, Zahid Ur Rehman**, Saad Ullah Khan***
* Department of Chemical Engineering UET Peshawar
** Department of Mining Engineering, UET Peshawar
*** Department of Chemical and Material Science Engineering GIK
Email: murtaza_forte@yahoo.com
Abstract
Whiteness and opacity of floor tile glazes are usually developed by changing composition of the raw materials. Traditionally, in ceramic tiles industry zirconium silicate (ZrSiO4) is widely used as opacifier. However, the high cost of zirconium limits its uses. In this study, alternative glazes with suitable whiteness and opacity were investigated using talc (Mg3Si4O10(OH)2) as opacifying agent and gradually eliminating ZrSiO4 content in the glazes. Six samples of glazes (including standard sample) were prepared, sprayed and fired in single fired floor tile roller kiln under industrial conditions. The microstructure and mineralogical composition of glazes were characterized by using Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray (Spectroscopy) EDX. Various physical tests were also done on all samples of glazes in order to investigate the effects of addition of talc on the floor tile glaze. The results of density of the sample glazes revealed that the density of the samples decreased by the addition of talc. The strength of the glazed and fired floor tiles was also tested which showed that the strength of glazed and fired floor tiles sample was not affected significantly, which is directly related to the ceramic tiles body composition and firing temperature of the kiln. The whiteness and opacity of glazes was measured by CIELAB color space. This research work revealed that the glazes containing talc were found more economic and better in fluxing properties, opacity and whiteness which may be attributed to crystalline structure of the talc.
Keywords: talc; opacifier; floor tiles; glaze.