2019 Volume 59 Issue 1 Pages 31-38
The viscous behaviors of CaO-SiO2-11.00wt%MgO-11.00wt%Al2O3-43.00wt%TiO2 slag systems were investigated by the rotating cylinder method in this paper, and the effects of CaO/SiO2 on the viscosity, break point temperature and activation energy for viscous flow of slag were analyzed. Meanwhile, the slag structural characterizations were studied by Fourier transformation infrared (FTIR) spectroscopy and Raman spectroscopy, and the phase compositions of pre-melted slags were detected by X-ray diffraction (XRD) analyses. The results show that, when the CaO/SiO2 increases from 0.20 to 0.80, the viscosity, break point temperature and activation energy for viscous flow of slag decrease. FTIR and Raman spectroscopy results indicate that the complex viscous units in slag are gradually depolymerized with the increase of CaO/SiO2, which improve the fluidity of slag. The depolymerization mechanism of silicate networks can be expressed by . The complex O–Ti–O deformation units are depolymerized into the simple structural units ( monomers, chains and Ti–O stretching vibrations in 6-coordinated Ti4+) and the [AlO4]- tetrahedrons are simplified to the [AlO6]- octahedrons. In addition, the relative amounts of low melting point complicated pyroxene in the pre-melted slag increase, improving the meltability of slag and decreasing the break point temperature.