Structure and performance of glass–ceramics obtained by Bayan Obo tailing and fly ash

• Glass and glass–ceramics have been obtained by Bayan Obo tailing and fly ash.
• We report the key role of Fe2O3, Cr2O3 and CaF2 from Bayan Obo tailing.
• Diopside, fluorite, quartz and silicon oxide have precipitated in glass–ceramics.
• The size of crystals in the glass–ceramic prepared by ourselves is below 300 nm.
• The structure of the glass–ceramic was characterized by using Raman spectroscopy.
• We provide an effective way for comprehensive utilization of Bayan Obo and fly ash.

Glass in the CaO–Al2O3–MgO–SiO2 quaternary phase system has been obtained by the Bayan Obo tailing and fly ash as main raw materials. On the basis of differential scanning calorimetry (DSC) analyses, this article took the glass and glass–ceramic samples which the Bayan Obo tailing and fly ash added respectively to 50% and 20% as the object of study. Nucleation experiment was carried out at 720 °C for 2 h whereas crystallization experiment was performed at 880 °C for 2 h. The phases and microstructure of glass and glass–ceramic samples were characterized by X-ray diffraction (XRD), Raman spectra, transmission electron microscopy (TEM) and scanning transmission electron microscope (STEM). In addition, physical and mechanical properties of the produced glass–ceramics have been examined. The results demonstrate that the glass–ceramics have potential for a wide range of construction application.