Influence of Cr2O3 on the viscosity and crystallization behavior of glass ceramics based on blast furnace slag

CaO–MgO–Al2O3–SiO2 glass-ceramics with various Cr2O3 contents are successfully prepared from blast furnace slag as the main raw material using a conventional melting method. The influence of Cr2O3 addition on the viscosity, crystallization kinetics, structure, and properties of the obtained materials are systematically determined by viscometry, differential scanning calorimetry, Fourier-transform infrared spectroscopy, X-ray powder diffraction, thermal-field-emission environmental scanning electron microscopy, and corrosion-resistance property tests. The results showed that the obtained glass-ceramics is composed of dendritic diopside (main crystalline phase) and bulk spinel (second crystalline phase). With increasing amount of Cr2O3, the viscosity of the slag glass melt increases. In addition, the samples exhibit crystallization activation energies in the range 378–454 kJ/mol, with slight fluctuations. Moreover, the crystallization index increases from 0.84 to 2.80. The obtained glass-ceramics exhibit a maximum density, bending strength, and acid and alkali resistances of 2.97 g/cm3, 196.69 MPa, 97.61%, and 98.04% respectively, demonstrating their wide application potential for various industrial applications. •Glass-ceramics with diopside and spinel phases were derived from blast furnace slag.•The parallel relationships are [001]diopside∥[111]spinel, [100]diopside∥[111]spinel.•The viscosity of CAMS-Cr2O3 slag glass increases with increasing Cr2O3 content.•Volumetric crystallization mechanism in samples when Cr2O3 is more than 1.0%.