The Effect of Zirconium Oxide on Properties and Crystallization of Soda-Lime Silicate Glass

In this study, the properties and crystallization of re-melted soda-lime silicate glass cullet added with Al2O3, CaCO3 and ZrO2 were investigated in order to study the potential usage as a parent glass for glass-ceramics. Al2O3, CaCO3 and ZrO2 were added into the 71SiO2-10Na2O-6K2O-5CaO-4MgO-2SrO-ZrO2-Al2O3 glass cullet to increase the crystallization of the glass. The glass batches (%wt) of (65-x) Cullet:13Al2O3:22CaCO3:xZrO2 (x = 0, 1, 2, 4, 6 and 8) were melted at 1500°C for 3 hours. The crystallization was investigated by Differential Scanning Colorimetry technique (DSC) and it was found that the glasses with 6 and 8 %wt of ZrO2 crystallized rapidly. It means that ZrO2 acted as the nucleating agent in this glass system. The major crystallines determined by X-ray diffraction technique (XRD) were silica (SiO2), wollastonite (CaSiO3) potassium silicate (K6Si3O9) and zirconium oxide (ZrO2). The thermal expansion of glasses determined by dilatometric method indicated the characteristic of glass-ceramics and the effect of ZrO2 on the thermal properties of glass. In conclusion, modifying the composition of soda-lime silicate cullet with Al2O3 CaCO3 and ZrO2 had potential to produce glass-ceramics.