Session: 10-06-02: Industrial Flows - II

Paper Number: 93971

93971 - Numerical Study and Validation of Hot Metal Desulfurization Using Calcium Carbide in the Ladle 

Hot metal desulfurization using lance injection in the transfer ladle is widely used in the industry. The desulfurization process is mainly controlled by injected desulfurization reagent with carrier gas. Commonly used desulfurization reagents include lime, calcium carbide, and magnesium powder. Many mathematical models are developed based on the thermodynamics, mechanism, and kinetics of hot metal desulfurization by using different reagents, but the majority of works are based on 1D calculation. The size of the reagent particle can be as small as 1-micron meter, but the size of the ladle is around several meters, and the gas, fluid, and solid multiphase interaction and reaction during the process is hard to simulate. Due to the complexity of multiscale and multiphase reactions of hot metal desulfurization, 3D Computational Fluid Dynamics (CFD) simulation is hard to achieve. So far, there is no comprehensive investigation of the prediction of desulfurization rate in a different region of ladle while optimizing ladle design and operating conditions based on simulation results. In order to optimize ladle design and operating conditions, the 3D transient Computational Fluid Dynamics (CFD) model is needed.

In this work, a 3D transient Computational Fluid Dynamics (CFD) model is developed to simulate hot metal desulfurization (HMD) using calcium carbide in the experimental scale ladle. The capacity of the ladle is 70 kg, and the iron temperature is 1623.15 K. The Eulerian-Eulerian multiphase model is employed to simulate liquid, gas, and solid multiphase behavior. The k-epsilon turbulence model is used to study the intense turbulent flow field. The species transport model is conducted to describe the movement and concentration of species. Meanwhile, the efficiency of reagent particles penetrating carrier gas bubbles is considered, and the penetration ratio is related to the gas flow rate and location of the injection port, which is expressed as an equation. In this model, the penetration ratio is calculated by the equation and applied to the simulation. As for validation work, the sulfur mass fraction calculated from the model is compared with experiment measurement. The result shows an average difference of 6.8% achieved. The model is able to predict species concentration and desulfurization rate at the different regions of the ladle. The dead zone can be found out. With the validated model, the effect of different parameters on desulfurization can be investigated. The effects of two different calcium carbide particle sizes and two different iron temperatures on desulfurization rates are discussed. The results show that smaller calcium carbide particles and higher iron temperatures can benefit the hot metal desulfurization rate.

Presenting Author: Xipeng Guo Purdue University Northwest

Presenting Author Biography: Xipeng Guo is a Ph.D. candidate at Purdue University West Lafayette, and a Research Assistant in the Center for Innovation through Visualization and Simulation (CIVS). He currently serves as a project student leader for the Ladle research teams at the Steel Manufacturing Simulation and Visualization Consortium (SMSVC).

Authors:

Xipeng Guo Purdue University Northwest
Congshan Mao Purdue University Northwest
Nicholas Walla Purdue University Northwest
Armin Silaen Purdue University Northwest
Chenn Zhou Purdue University Northwest