Effect of Cr₂O₃ Addition on Sintering Behavior of Novel Chromite-Based Ladle Filler Sand

Developing novel filler sands has garnered significant interest in improving the ladle's free-opening rate and enhancing the cleanliness of high-Mn and high-Al steel. Laboratory studies explore the effect of adding Cr2O3 powder on the sintering behavior of chromite-based filler sands. Furthermore, interfacial phenomena are examined between the sands and the steel grades, varying in Mn contents. The results demonstrate that adding Cr2O3 power plays a role in inhibiting the liquid phase formation in the sand. With a 16% addition, the steel (Mn mass% = 30) reacts with the sand, leading to the shape of a spinel phase, specifically (Mn, Fe, Mg)O(Al, Cr)(2)O-3, which facilitates the separation of the liquid phase. The reduction of FeO to Fe by Mn, Al, and C in steel, especially Al, is hindered by adding Cr2O3, resulting in a suitable sintering degree that ultimately benefits ladle free-opening. SiO2 is crucial for forming the liquid phase during the sintering process. The SiO2 content of the sand should be about 20% to achieve optimal sintering effects. Chromite sand for casting is not suitable for the steels. The mixed sand presented in the current study demonstrates potential as a suitable filler sand for the steel (20 <= Mn mass% <= 30).