Experimental Procedure The system kaolinite, quartz, Na-feldspar and waste glass (50, 28, 15-22, 0-7 wt%, respectively), the latter in partial substitution of flux, was explored using three different particle size distribution for waste glass (<=100, <=75 and <=45 ?m) and two for quartz (<=160 and <=20 ?m). Samples have been fired at 1140 and 1170 °C for 20, 40, 60, 80 and 240 minutes and then characterized in terms of phase composition (X-ray diffraction using Rietvel Method), micro-structure occurrence (Scanning Electron Microscopy), water absorption, linear shrinkage and modulus of rupture. Results Differences in phase composition are present: in particular, glass substituting Na-feldspar accelerates the mullite growth (Marinoni et al., 2001; Marinoni et al., 2013) and the same effect is achieved by decreasing the quartz grain size, which leads to a higher reactivity of the starting slip and to a lesser vitrification grade. Cristobalite occurs only in the samples containing waste glass and more complex effects due to the waste glass particle size are observed. The slopes of the mullite phase at given temperature increase in function of time exhibit behaviors in keeping with earlier findings (Bernasconi et al., 2011). Furthermore, secondary mullite seems more abundant and better shaped in samples with small-size quartz. The particle size distribution of the silica-components, soaking time and heating temperature influence the thermal-mechanical properties, as shown by tests on macroscopic ceramic bodies. The presence of smaller quartz together with larger waste glass preserves acceptable technological properties. REFERENCES Bernasconi A., Diella V., Pagani A., Pavese A., Francescon F., Young K., Stuart J. & Tunnicliffe L. 2011. The role of firing temperature, firing time and quartz grain size on phase-formation, thermal dilatation and water absorption in sanitary-ware vitreous bodies. J. Eur. Ceram. Soc., 31, 1353-1360. Marinoni N., Pagani A., Adamo I., Diella V., Pavese A. & Francescon F. 2011. Kinetic study of mullite growth in sanitary-ware production by in situ HT-XRPD. The influence of the filler/flux ratio. J. Eur. Ceram. Soc., 31, 273-280. Marinoni N., D'Alessio D., Diella V., Pavese A. & Francescon F. 2013. Effects of soda-lime-silica waste glass on mullite formation kinetics and micro-structures development in vitreous ceramics.Journal of Environmental Management 124, 100-107.
The influence of quartz and waste glass particle size distribution on the evolution of sanitary-ware vitreous body.
2015
Abstract
Experimental Procedure The system kaolinite, quartz, Na-feldspar and waste glass (50, 28, 15-22, 0-7 wt%, respectively), the latter in partial substitution of flux, was explored using three different particle size distribution for waste glass (<=100, <=75 and <=45 ?m) and two for quartz (<=160 and <=20 ?m). Samples have been fired at 1140 and 1170 °C for 20, 40, 60, 80 and 240 minutes and then characterized in terms of phase composition (X-ray diffraction using Rietvel Method), micro-structure occurrence (Scanning Electron Microscopy), water absorption, linear shrinkage and modulus of rupture. Results Differences in phase composition are present: in particular, glass substituting Na-feldspar accelerates the mullite growth (Marinoni et al., 2001; Marinoni et al., 2013) and the same effect is achieved by decreasing the quartz grain size, which leads to a higher reactivity of the starting slip and to a lesser vitrification grade. Cristobalite occurs only in the samples containing waste glass and more complex effects due to the waste glass particle size are observed. The slopes of the mullite phase at given temperature increase in function of time exhibit behaviors in keeping with earlier findings (Bernasconi et al., 2011). Furthermore, secondary mullite seems more abundant and better shaped in samples with small-size quartz. The particle size distribution of the silica-components, soaking time and heating temperature influence the thermal-mechanical properties, as shown by tests on macroscopic ceramic bodies. The presence of smaller quartz together with larger waste glass preserves acceptable technological properties. REFERENCES Bernasconi A., Diella V., Pagani A., Pavese A., Francescon F., Young K., Stuart J. & Tunnicliffe L. 2011. The role of firing temperature, firing time and quartz grain size on phase-formation, thermal dilatation and water absorption in sanitary-ware vitreous bodies. J. Eur. Ceram. Soc., 31, 1353-1360. Marinoni N., Pagani A., Adamo I., Diella V., Pavese A. & Francescon F. 2011. Kinetic study of mullite growth in sanitary-ware production by in situ HT-XRPD. The influence of the filler/flux ratio. J. Eur. Ceram. Soc., 31, 273-280. Marinoni N., D'Alessio D., Diella V., Pavese A. & Francescon F. 2013. Effects of soda-lime-silica waste glass on mullite formation kinetics and micro-structures development in vitreous ceramics.Journal of Environmental Management 124, 100-107.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
