3. Methodology for Preparation Samples from Waste and Techniques for Characterization

The samples were produced via melt-quenching technique followed by powdering, pressing, and sintering. In the first stage the soda-lime-silicate (SLS) glasses were crushed, grounded, and sieved to gain the expected particle size. The prepared powder was mixed with ZnO followed by melting at the temperature of 1400 °C and quenching in water to obtain fritz glass. The prepared fritz glass was crushed using mortar and pestle to the size of 63 μm. After that the prepared powder was heat treated at the temperature of 1000 °C to produce willemite. The willemite-based glass-ceramic was doped with trivalent erbium (Er³⁺) in the ([(ZnO)_0.5(SLS)_0.5]1-x[Er₂O₃]x) composition where x = 1–5 wt.%. At the end, the powder was pressed, and different pallets were prepared and finally sintered at different temperatures ranging from 500 to 1100 °C. The crystal (phase) changes with different contents of Er₂O₃, and different sintering temperatures were investigated using X-ray diffraction (XRD); the binding structure was explored by Fourier-transform infrared spectroscopy (FTIR); the microstructure, morphology, and chemical composition were studied using field emission scanning electron microscope (FESEM) along with EDAX; and the optical properties were analyzed by UV-VIS spectroscopy.