Effect of Al<sub>2</sub>O<sub>3</sub> on the Glass-Ceramics of CaO-SiO<sub>2</sub>-MgO-Al<sub>2</sub>O<sub>3</sub> System Based on BOF Slag

Abstract

Directly recycling residual iron element in modified BOF slag after reduction and manufacturing glass-ceramics from these remaining inorganic slag materials is an effective way to reuse the waste heat and slag materials of hot BOF slag. In the glass-ceramics, the Al2O3 has an important influence on the slag viscosity and the physical and chemical properties of glass-ceramics. In this paper, glass-ceramics with a basicity of 0.7 and a MgO content of 9~12% were prepared by using chemically pure reagents according to the CaO-SiO2-MgO phase diagram, and the effect of different Al2O3 content on the parent glass crystallization and glass-ceramic performances was studied. Results show that the flexural strength of glass-ceramics is mainly affected by the sintering shrinkage. When the weight content of Al2O3 exceeds 15%, both the flexural strength and the shrinkage rate reached the maximum, and dense microstructure was obtained. In addition, the original dominant crystal structure is affected while Al2O3>12%, with the anorthite crystal phase appearing consequently.