Effect of Al<sub>2</sub>O<sub>3</sub> and TiO<sub>2</sub> on Viscosity, Surface Tension, and Density of Blast Furnace Slag with CaO/SiO<sub>2</sub> = 1.13
Gert Bartzsch, Rennie Christian, Soumya R. Mohanty, Ajay Kumar Shukla, Olena Volkova
Abstract
The influence of Al 2 O 3 in the range of 10–20 mass% and TiO 2 in the range of 0.55–5 mass% on the flow behavior, viscosity, density, and surface tension of molten industrial blast furnace slag with CaO/SiO 2 = 1.13 is investigated using a high‐temperature microscope, a rotating viscometer, and the maximum bubble pressure method. The measurement results show that Al 2 O 3 acts as a network former in the studied CaO–SiO 2 –MgO–Al 2 O 3 –TiO 2 slags. With an increase in the Al 2 O 3 content from 10 to 20 mass%, the viscosity and surface tension of the slags increase and the density decreases. In contrast to Al 2 O 3 , the TiO 2 acts as a surfactant and network breaker in the range of up to 15 mass%. The addition of TiO 2 up to 15 mass% results in a decrease in the viscosity in the liquid‐dominated region and a decrease in the surface tension of the studied slags. Therefore, the density increases with the addition of TiO 2 due to increasing molar volume. The behavior of the breakpoint temperature on all the viscosity curves is in complete agreement with the behavior of the flow point temperature and crystallization temperatures of melilite and perovskite.