Abstract
In recent decades, significant research efforts have been directed toward the production and development of zinc silicate-based glass-ceramics due to their promising functional properties. Advancing these efforts through the utilization of secondary raw materials represents a pivotal step in sustainable materials development. In this work, zinc silicate glass-ceramics were successfully synthesized employing waste soda lime silica (SLS) as an alternative silicon source, highlighting a novel approach to both material fabrication and glass waste valorization. The glass system were synthesized via the conventional solid-state melt-quenching route, followed by a sintering process to induce crystallization. The physical and structural, characteristics of the glass system were systematically investigated using density measurements, X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and Field emission scanning electron microscopy (FESEM) respectively. The results indicate that increasing the sintering temperature from 500 °C to 700 °C enhanced the density of the 50Z glass samples from 3.1042 g/cm³ to 3.1943 g/cm³, and from 3.0797 g/cm³ to 3.1651 g/cm³ for the 45Z glass samples. This increase in density is primarily attributed to improved structural compactness at higher sintering temperatures. XRD analysis revealed an amorphous phase for all samples sintered between 500 °C and 650 °C for both compositions (45Z and 50Z). However, at 700 °C, the formation of willemite crystalline phases was observed, with crystallinity levels of 51.4% for 50Z and 49.5% for 45Z, respectively.
The increased band intensity with higher temperatures indicates enhanced structural order and crystalline phase formation. The FESEM analysis effectively reveals the sintering temperature-dependent morphological transitions in the studied glass-ceramics. The increase in ZnO content notably enhances crystallization behavior, as reflected in the increased grain density and improved nucleation at higher sintering temperatures. The FESEM findings are in alignment with the crystallographic data obtained from XRD and affirm the critical role of thermal treatment in tailoring the microstructure of glass-ceramic systems. These findings underscore the viability of converting SLS glass waste into functional zinc silicate glass-ceramics, offering a dual benefit of environmental remediation and the development of luminescent materials suitable for advanced material application.

Key words: Glass- ceramic, Melt-quenching, Waste SLS glass, Amorphous.