Effect of TiO₂ on the viscosity and slag structure in blast furnace type slags

TiO₂ additions up to 10mass% behaved as a basic oxide and lowered the viscosity in the CaO-SiO₂-17mass% Al₂O ₃-10mass% MgO-based slags by depolymerizing the silicate network structure. Raman spectroscopy revealed the sum of NBO/Si 1 and 3 decreased while the sum of NBO/Si 2 and 4 increased with TiO₂ content. Unlike the silicate structures, the aluminate structures seems to be relatively unaffected by TiO₂ additions according to the FTIR results. 5mass% TiO ₂ significantly decreased the viscosity compared to the TiO ₂ free slags, but beyond 5mass% TiO₂ meaningful changes in the viscosity was not observed. From the comparison of the viscosity at constant TiO₂ of 5 and 10mass% and varying CaO/SiO₂ ratio, increasing the CaO/SiO₂ ratio was more effective in decreasing the viscosity than TiO₂ additions. TiO₂ additions lowered the viscosity of blast furnace type slags by depolymerizing the silicate network, but did not significantly affect the aluminate structures within the slags. TiO₂ (5mass%) decreased the viscosity, but higher TiO₂ showed no meaningful changes in the viscosity. Increasing the CaO/SiO ₂ ratio was more effective in decreasing the viscosity than TiO ₂ additions.