Influence of crucible material on the microstructure and properties of iron rich glass-ceramics

Slag glass melting is usually performed on a laboratory scale in crucibles, which are economically viable tools for the production of slag glass-ceramics. In this work, quaternary CaO-Al 2 O 3 -MgOSiO 2 (CAMS) glass-ceramics were prepared by melting the tailing of Bayan Obo mine tailing, blast furnace slag, and fly ash in alumina and graphite crucibles. The effect of the crucible material on the microstructure and properties of the glass-ceramics was investigated using differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and inductively coupled plasma atomic emission spectroscopy. Results indicated that the contents of Al 2 O 3 and Fe 2 O 3 in the initial glass were significantly changed by the corrosion of the alumina crucibles during the glass melting process and by the reducing action of the graphite crucibles. The main crystal phases of glass-ceramics melted in alumina crucibles and graphite crucibles were Ca (Mg, Fe, Al) (Si, Al) 2 O 6 , coesite and Ca (Mg, Al) (Si, Al) 2 O 6 , respectively. According to these findings, we conclude that the microstructure and properties of the glass-ceramics are affected by the crucibles.