Discharging properties of tundish slag for an improved hot-tundish recycling process

Abstract

The discharging properties of tundish slag for an improved hot-tundish recycling process were investigated using a lab-scale discharging experiment at 1773 K. The sticking ratio of the slag (defined as the weight ratio of the sticking slag on a Al2O3 crucible after discharging to the total slag at the moment of discharging) was found to decrease with increasing basicity ((%CaO)/(%SiO2)), Fe,O content and discharging temperature, and decreasing Al2O3 content. While the substitution of MgO for CaO increases the sticking ratio, Al2O3 and SiO2 show nearly identical effects on it. The experimental results were discussed in terms of the physical properties of slag, viz. viscosity and wettability. Finally, both sticking ratio and erosion tendency were linked with optical basicity, and an optimum region of slag composition for an improved hot-tundish recycling process was proposed. With the proposed slag condition, the suitability of the plant slags for an optimized process was investigated.