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

Al 2 O 3 -SiO 2 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 T g and T c of the glass decreased with an increase in the ZnO amount. As the ZnO content increased from 2 wt. % to 4 wt. %, the E a 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 Q 0 and Q 2 reached the maximum, and Q 1 and Q 3 reached the minimum, meanwhile, the main structure of the glass changed from Q 1 to Q 2 . 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.