Increasing Energy Efficiency through Improvements in Ladle Materials and Practices

Steel foundry ladle practices play an important role in total energy efficiency of melting as well as influence casting quality. Extensive heat losses in the ladle could be associated with excessive superheating of the melt before tap which increases energy consumption, promotes oxidation of the melt and increases refractory consumption. A high cooling rate of the liquid metal in the ladle could also cause casting quality instability. The overall ladle heat balance and components of heat losses were analyzed using FLUENT and FACTSAGE software and validated with experimental data from both the UMR foundry and industrial foundries. The purpose of this paper is to study foundry steel ladles with a focus on increasing energy efficiency through the use of novel lining materials and special techniques of decreasing thermal losses. Special low thermal conductivity materials have been proven to decrease the heat losses significantly resulting in an increase in the holding times and allowing tap temperatures to be decreased by up to 200 degrees F, depending on ladle practices. The laboratory experimental data were incorporated into a computer model that predicts conditions in industrial foundry ladles