Influence of high field strength ions on the crystallization characteristics and properties of slag glass-ceramics

Abstract

Blast furnace slag glass–ceramics were prepared by melting using rare-earth-containing blast furnace slag (REBFS) as the main raw material and Fe2O3 and Cr2O3 as composite nucleating agents. By adding different TiO2 contents, the study comprehensively revealed the effects of high field strength ions on the glass network structure, crystalline properties, elemental distribution and physicochemical properties. Raman spectroscopy and differential scanning calorimetry revealed that TiO2 acted primarily as a network modifier in the glass network. The appropriate TiO2 content disrupted the glass network, decreasing the crystallization activation energy (EC) of the glass–ceramic. However, excess TiO2 repaired the network structure, thereby increasing the EC. The combined effect of the Cr and Ti substantially improved the crystallization characteristics of the glass-ceramics. Cr2O3 induced the formation of spinel, which promoted the crystallization of the main crystalline augite phase. The self-aggregation of the high field strength Ti4+ ion induced the formation of a titanium- and cerium-containing titanite phase, which also contributed to grain refinement. This titanite phase effectively increased the Vickers hardness and acid and alkali resistances of the glass-ceramics to 9.16 GPa and over 98.5 %, respectively. The excellent physicochemical properties render REBFS glass–ceramics as being promising materials for various construction applications. This research provides theoretical support for comprehensively utilizing blast furnace slag and provides theoretical guidance for preparing slag glass–ceramics possessing desirable physicochemical properties.