Preparation and characterization of the glass-ceramics by co-utilization of ferrochromium slag and titanium-bearing blast furnace slag

Ferrochromium slag (FCS) and titanium-bearing blast furnace (TBFS) were used as the main raw materials to prepare glass-ceramics by the conventional melting method in this study. The DTA tests and crystallization kinetics analysis were conducted to determine the optimum heat-treatment temperatures. The effects of FCS and TBFS addition on the glass-ceramics crystalline phase, microstructure evolution, and physical properties were investigated systematically. The results show that the dominant crystalline phases are Cr-containing augite and wollastonite in the glass-ceramics prepared from single FCS. With the increasing addition of FCS, though the crystallization ability enhanced continuously, a large amount of Cr-containing spinel precipitated, resulting in serious shrinkage cavities. When the TBFS was introduced into FCS glass-ceramics, the original silicon-oxygen was destroyed and the titanium-oxygen-silicon composite glass network formed. The ability of crystallization is further enhanced and the size of the grain is significantly refined. Simultaneously, the Cr-containing spinel is decreased obviously, which alleviates the shrinkage cavities and improves the mechanical properties of glass-ceramics. The final obtained glass-ceramics exhibits a flexural strength of 86.7 MPa, a Vickers hardness of 741.1 HV, a bulk density of 2.96 g/cm3, a water absorption rate of 0.36%, and a Cr ion leaching concentration of 0.66 mg/L. This study clarifies the mechanism of Cr2O3 and TiO2 in glass ceramics, which has important reference significance for the value-added utilization of FCS and TBFS.