Effects of TiO₂ and alkalinity on viscosity and structure of CaO-MgO-Al₂O₃-SiO₂-Cr₂O₃-Fe₂O₃-TiO₂ slag system and solubility of chromium oxide

To make more use of stainless steel slag to prepare glass-ceramics to solidify Cr in slag, this paper systematically studied the effects of different TiO₂ and alkalinity on the solubility of Cr₂O₃ in CaO-MgO-Al₂O₃-SiO₂-Cr₂O₃-Fe₂O₃-TiO₂ slag system and the adhesion and melting characteristics of slag system. The changes in viscosity, phase composition and structure of slag system with different TiO₂ content (4%-10%) and alkalinity (C/S=0.5,0.75,1) were investigated using melt physical property comprehensive tester, XRD and Raman spectrometer. The results show that with the increase of TiO₂ content and alkalinity, the solubility of Cr₂O₃ in the slag sample increases, the viscous flow activation energy decreases, and the viscosity of the slag system also decreases accordingly. Compared with TiO₂, increasing alkalinity can effectively reduce viscosity. The increase of TiO₂content and alkalinity increases the number of Q⁰ and Q¹ structural units in the slag, while the decrease of Q³ simplifies the silicate network structural units and reduces the viscosity of the slag system. At the same time, it also hinders the crystallization of chromium-containing spinel and increases the solubility of Cr₂O₃ in the slag sample.