Summary: | A new process with argon injected into the ladle around the tapping hole for controlling slag carry-over in a teeming ladle was presented. Physical modeling was used to study the mechanism of controlling slag carry-over, and the feasibility of the new process was also investigated by industrial trials. The results show that vortex forms firstly, and then converts to drain sink. With argon injected into the ladle around the tapping hole, an argon ring was formed, and the rotating angular velocity of the melt close to the tapping hole reduced dramatically, and even vanished when the melt passed the argon ring. Therefore, the new controlling slag carry-over process can eliminate the slag carry-over caused by vortex. The velocity of the melt toward the tapping hole was reduced due to the bubble buoyancy as the melt passed the argon ring. So, the new process can decrease the critical height of slag carry-over caused by drain sink. The application feasibility of the new controlling slag carry-over process is verified by the plant trials. Compared to the traditional teeming ladle process, the new controlling slag carry-over process shows much better efficiency on decreasing the steel residual in the poured ladle.
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