Crystallization behavior and structure of CaO–MgO–Al2O3–SiO2 glass ceramics prepared from Cr-bearing slag

Glass ceramics were successfully prepared from Cr-bearing slag and the effect of the slag content (40–70 wt%) on the crystallization behavior and morphology of the glass ceramics was investigated. The values of the crystallization activation energy and crystallization index for crystal growth calculated using various methods were consistent. The crystallization activation energies of the samples exhibited in the range of 165–252 kJ/mol, and it tended to decrease with increasing Cr-bearing slag content. The crystallization index results indicated that the crystallization mechanism of the samples is bulk crystallization. Additionally, the principal phase composition of the glass ceramics with Cr-bearing slag contents of 40, 50, and 60 wt% was diopside; however, anorthite precipitated as a second phase when the slag content was 65% or 70%. Furthermore, the results suggesting that the CMAS glass ceramics could also be synthesized from Cr-bearing slag without using an additional nucleating agent. •Glass ceramics with 40–70 wt% Cr-bearing slag were successfully synthesized without using an additional nucleating agent.•The values of the crystallization kinetics parameters for crystal growth calculated using various methods were consistent.•Spinel can promote crystallization and the crystallization mechanism of the samples is bulk crystallization.•The crystalline phase of the obtained glass ceramics changes from diopside to diopside–anorthite.