Application of an Improved Tracer in a Water Model of Ladle

The various refining functions in the ladle process are closely associated with the flow behavior of molten steel. In most current studies, high-density salt solution tracers are commonly used in water model studies due to their ease of preparation. However, their relatively large density compared with water can introduce significant experimental error. To more accurately evaluate steel flow behavior, this study introduces, for the first time, a salt solution–ethanol-mixed tracer with a density of 1.075 g/mL for use in a water modeling of ladle with an eccentrically placed single plug, with a water volume of 97 L. The results show that upon injection into the water model, the saturated NaCl solution rapidly sinks due to inertia and buoyancy forces, which disturbs the flow field (density effect). This sinking effect becomes more pronounced with increasing the tracer dosage (volume effect). When the dosage exceeds 42 mL, the tracer transport mode shifts from “main circulation zone to secondary circulation zone” to a “center-to-sides” distribution. Significant deposition of salt solution at the bottom is also observed. In contrast, the improved tracer effectively mitigates the density and volume effects associated with saturated NaCl solution, resulting in a more uniform and stable transport process within the water model and reduced deposition at the ladle bottom. For both tracers, the mixing time at the ladle bottom first decreases and then increases with increasing dosage. However, the turning point occurs at 40 mL for the saturated NaCl solution and at 61 mL for the improved tracer. Overall, the improved tracer exhibits lower sensitivity to dosage variation and is better suited for representing mixing behavior in actual ladle metallurgical processes.