Crystallization and vitrification behavior of CaO-SiO2-FetO-Al2O3 slag: Fundamentals to use mineral wastes in production of glass ball

摘要: Abstract In this study, we investigated the effect of CaO/SiO2 (C/S) ratio on crystallization behavior CaO-SiO2-FetO-Al2O3 slag system, which simulates mixed mineral wastes red mud, mine tailings, and waste limestone, using a differential scanning calorimetry (DSC) technique. The both isothermal non-isothermal cooling was simultaneously evaluated X-ray diffraction (XRD) analysis electron microscopy (SEM) images. calculated equilibrium phases, such as pseudo-wollastonite (ps-CaSiO3) melilite (Ca2[Al,Fe][Si,Al]2O7), crystallized during process at different C/S ratios (=0.65–1.02). were varied by simulating various mixing among limestone. Even with relatively low rate 5 °C/min, none exothermic peaks detected cooling, irrespective ratio. However, phases in samples identified XRD SEM analyses, except for C/S = 0.65 slag. Ability increased increasing due to fluidity slags based structural consideration. As result, our findings show that is increasingly difficult decrease Although holding remains between 900 °C 1200 °C long period time high basicity (C/S = 1.02) present weak delayed observed Consequently, study provides evidence (C/S = 0.65–1.02) exhibit strong vitrification characteristics control melts viscosity important granulation produce commercial grade glass ball tailing