SINTERING MECHANISM, STRUCTURE AND CRYSTALLISATION OF CaO-MgO-Al₂O₃-SiO₂GLASS-CERAMICS FROM BLAST FURNACE SLAG

Abstract

CaO-MgO-Al₂O₃-SiO₂ glass-ceramics with different amounts of ZnO from blast furnace slag were prepared using the sintering method. The structure and properties of the glasses or glass-ceramics were investigated by Raman, DSC, HSM, XRD, and FE-SEM. The Tg and Tc of the glass decreased with an increase in the ZnO amount. As the ZnO content increased from 2 wt.% to 4 wt.%, the Ea of the glass decreased and the sinterability increased, while with any further increase in the ZnO content, the sinterability decreased. The Raman analysis showed that when the ZnO content was 4 wt.%, the adjustment of the glass structure was obvious. The relative area of Q⁰ and Q² reached the maximum, and Q¹ and Q³ reached the minimum, meanwhile, the main structure of the glass changed from Q¹ to Q². The main crystal phase of the glass-ceramics was akermanite; ZnO promoted the precipitation of akermanite, but inhibited the precipitation of diopside. With the increase in the ZnO content, the bulk density of the glass-ceramics increased while the flexural strength and microhardness decreased.

Keywords

• cmas glass-ceramics
• sintering mechanism
• blast furnace slag
• zno