Optimization of performance and crystallization behavior of glass-ceramics from industrial solid waste using response surface methodology

Abstract

This study investigates the development of high-value added glass-ceramics from low-value industrial solid waste, employing response surface method (RSM) for optimization and evaluation. The effects of CaF₂, MgO, CaO content and Si/Al ratio on key properties — water absorption, acid resistance, alkali resistance and density were systematically investigated. The optimal composition was determined to comprise 25 wt.% CaF₂, 8 wt.% MgO, 9 wt.% CaO and a Si/Al ratio of 1.8. Predicted value for water absorption, acid resistance, alkali resistance and density were 0.02863 %, 100.014 %, 100.015 % and 2.927 g/cm³, respectively. The corresponding experimental values were 0.029 %, 99.97 %, 99.98 % and 2.94 g/cm³, showing excellent agreement with the model predictions and validating the reliability of the RSM approach. The microscopic mechanism underlying the optimal composition were explored through Raman spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The parent glass exhibited volume crystallization, characterized by crystal growth and formed, precipitation through a three-dimensional interface. At 700 °C, CaF₂ crystals formed as small, well-dispersed particles. As the heat treatment temperature increased, the crystalline phased evolved, with the formation of anorthite and calcium aluminum fluoride silicate, which led to significant grain growth and crystal aggregation. This research provides a theoretical basis for the efficient utilization of industrial solid waste, demonstrating for conversion into high-value glass-ceramics, thereby contributing to sustainable resource development.