Preparation of SiO₂-Na₂O-CaO-P₂O₅ Glass-Ceramic from Waste Materials and Heat Treatment Effects on its Morphology

Abstract

Currently, many researchers interested studying waste materials to recycle them or reuse them in new products. From the sustainable perspective development, it is necessary to implement new technologies to help reduce waste and thus minimize the environmental problems associated with disposal. In this study, the preparation of SiO2-Na2O-CaO-P2O5 (SNCP) glass-ceramic is composed of Soda Lime Silicate (SLS), Clam Shell (CS), Na2CO3 and P2O5 in the ratio of 50: 25: 20: 5 respectively. The waste materials that were used for fabricate glass-ceramic are SLS and CS. All the compounds were mixed to fabricate the SNCP glass-ceramic through solid state reaction. The samples were investigated through X-ray diffraction (XRD), field emission microscope (FESEM) and density measurement. The samples were sintered at temperature 550°C, 650°C, 750°C, 850°C until 950°C. The main phase obtained from XRD analysis is Sodium Calcium Silicate, Na2CaSiO4 with cubic crystal system at 550°C. The highest intensity phase of the diffraction peak is (220) and at the angle 33.7°. There was new peak presence at right side of the main phase Na2CaSiO4, which belong to Silicon Phosphate, SiP2O7 at 650°C and 750°C.When heat treatment increased at 850°C - 950°C, the main phase is Combeite, Na4Ca4(Si6O18) at diffraction peak (220) with rhombohedral crystal system which is assigned to high crystallization temperature (Tc). The density of samples increases at 550°C - 750°C and decreases when heat treatment 850°C - 950°C. Sample density decreases at heat treatment 850°C - 950°C due to increases of sample lattice parameter. FESEM analysis showed that the grain size and porosity increased when the heat treatment increased.

INFLUENCE OF DIFFERENT CaF₂ CONTENTS AND HEAT TREATMENT TEMPERATURES ON APATITE-MULLITE GLASS CERAMICS DERIVED FROM WASTE MATERIALS

“…As shown in Figure 1, the sample density decreased as the temperature of the heat treatment rose until the maximum temperature of 1000 °C was achieved. The same outcome was revealed by previous studies which explained that the decrease in the density measurement of the samples after they reached their optimal temperature was due to the increasing of the lattice parameter and the volume of the samples [40]. The heat treatment process supplied energy to the particles in the sample, which caused the atom to vibrate and rearrange from a random ordered, amorphous phase of the glass to a properly ordered, crystalline phase of glass ceramics.…”