Melt Flow and Scrap Melting Characteristics in a Bottom-Blown Hot Metal Ladle
摘要
The global steel industry’s shift toward green manufacturing is intensifying the need for efficient scrap utilization. A three-dimensional mathematical model coupled turbulent flow, solidification/melting behavior, and species transfer was established to investigate the melt flow and scrap melting characteristics in a 210 t bottom-blown hot metal ladle. The study systematically evaluated the effects of argon blowing rate, scrap carbon content, preheating temperature, and specific surface area. Key results indicated that increasing the argon blowing rate to 200 L min−1 can reduce dead zones and shorten scrap melting time by up to 77 pct. Scrap carbon content emerged as a critical factor, with high-carbon scrap (1.836 and 3.672 wt pct) forming a thin solidified layer and melting completely within 120 seconds, whereas low-carbon scrap (0.183 to 0.612 wt pct) formed a thicker solidified layer (volume increase to 158 pct of the original volume), prolonged melting time to 200 to 375 seconds. Preheating the scrap to 1273 K can reduce the initial solidified layer volume to 107 pct of its original volume and shorten the initial melting time by about 38 pct, though its effect on the subsequent melting stage was limited. Geometrically, cylindrical scrap (239 m2 m−3) melting is 16.7 pct faster than a cubical pieces due to superior heat exchange. The present work can provide a validated strategy for enhancing scrap melting efficiency in various iron-carbon vessel.