Effect of CaO on Sintering and Crystallization of CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub> System Phosphorus Slag Glass-Ceramic

Abstract

Much phosphorus slag which is produced every year, not only brings about the resource waste, but also results in the pollution of the environment. In the paper, phosphorus slag was added into the glass-ceramics of CaO-Al2O3-SiO2 system. Through increasing the CaO content of CaO-Al2O3-SiO2 system glass-ceramics and keeping constant content of the phosphorus slag, the phosphorus slag glass-ceramics were obtained. The optimum compositions of CaO-Al2O3-SiO2 system phosphorus slag glass-ceramics was obtained through careful analysis based on X-ray diffraction (XRD), scanning electron microscopy (SEM) and other measuring methods. The results showed that with increasing of CaO content, the leveling temperature, the crystal content and the densities of samples were gradually increasing, however, the leveling temperature range was gradually narrowing. When the content of phosphorus slag was 30wt%, the addition of 17wt%CaO was more reasonable. The main phase of phosphorus slag glass-ceramic was β-wollastonite. The leveling temperature range of glass-ceramic was 1130-1140°C and the holding time was 2 hours.