Preparation of glass-ceramics largely using steelmaking slags and study on the effect of iron content on properties of glass-ceramics

Glass-ceramics were prepared using steelmaking industry waste containing high iron content based on powder sintering and crystallization method. Anthracite was used in varying amounts as the reducing agent to recover iron in raw materials. X-ray diffraction analysis (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscope (SEM) coupled with Energy Dispersive X-ray spectrometer (EDX) were used to study the microstructure of glass-ceramics formed. Bending strength and micro-harness of the samples were compared.;When 12g of anthracite was used, ionic iron (Fe2+/Fe 3+) content was reduced to 4.7% and total iron content was reduced to 8.0% in parent glass. The main crystalline phases formed were diopside and augite. Crystalline phases were well-distributed ranging between 0.2 to 0.4 microm after crystallization. A maximum bending strength of 91MPa and a maximum micro-hardness of 3466MPa were achieved.;Effect of Al2O3 content on glass-ceramics was studied. Both average bending strength and average micro-hardness of glass-ceramics with 15% Al2O3 content were higher than the glass-ceramics with 6% Al2O3 content.;Blast furnace dust was used as both a reducing agent to recover iron and a raw material to prepare glass-ceramics. Compared with glass-ceramics using anthracite as the reducing agent, average bending strength of glass-ceramics formed using BF dust was lower, while average micro-hardness was higher.