Preparation of innovative glass-ceramic materials based on mica schist within the CaO-MgO-Al₂O₃-SiO₂ system

The preparation of affordable glass-ceramic materials by induced crystallization of glass-based mica schists and other natural raw materials (dolomite & limestone), as well as magnesite as a mine waste, was investigated for the first time. Five glass batches were designed based on the eutectic composition of the diopside-anorthite ratio with increasing the enstatite content from 0-40 wt.% within the quaternary CaO-MgO-Al2O3-SiO2 system. After melting at 1400 to 1500 degree celsius, casting into discs & rod shapes, and annealing process, the prepared glasses were subjected to careful heat treatment schedules. Several techniques were used to characterize the applied raw materials, glass, and glass-ceramic materials such as X-ray Fluorescence (XRF), Differential Thermal Analysis (DTA), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Polarizing-light Microscopy. The produced glass-ceramic from the glass batch with 30 wt% enstatite that was nucleated at 750 degree celsius/2h followed by crystallization at 950 degree celsius/h, displayed the well-developed product on the level of volume crystallization and pore formation.